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A MANUAL
OF
ELEMENTARY CHEMISTRY,
THEORETICAL AND PRACTICAL.
BY GEORGE FOWNES, PH.D.
From  the Tenth Revised and Enlarged English Edition.
itt1 one 1junbTe6 A    nnt n g-shQeben 5 J lFation6.
EDITED BY ROBERT BRIDGES, M. D.,
Professor of Chemistry in the Philadelphia College of Pharmacy.
In one large and handsome royal 129no. volume of about 850 closely prinzted
pages; extra cloth, $2 75; leather, $3 25.
Enough of the old structure remains, however, to give to the work a familiar look
to its early friends, with many of whom it deservedly holds a high place among elementary books on chemistry. Its comparative fulness of detail and general simplicity
of style render it convenient and attractive as a book of reference for both teachers
and students, especially medical students; while for the purposes of a drill book in
class-room instructions, its very fulness is a bar to its usefulness for that purpose.
In the hands of an expert teacher, however, who is master of the science, it is an
admirable book, and equally so to the student who wishes faithfully to review the
teachings of the chemical lecture-room.-Silliman's Journal, Nov. 1869,
It would almost appear superfluous to say anything about Fownes' Chemistry.
Nearly a generation of Chemists have been brought up on it, and as the science has
advanced, and one discovery after another has rendered changes in the text necessary, the proper alterations have been made, and it has kept pace with the demands
of the times. We do not see how the student could procure a more thorough treatise
than the present edition of Fownes.'-Journal of Applied Chemnistry, Dec. 1869.
This tenth edition, with its complete revision, makes it, in our judgment, the best
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The amount of matter condensed into this small volume is almost wonderful. It
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achieve a large success and wide popularity.-Chicago Med. Journal, Oct. 1869.
This is a new and improved edition of one of the very best text-books on this science.-St. Louis M3ed. Archives, Oct. 1869.
It is sufficient to state, that this is the text-book recommended by the medical
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Journal, Sept. 1869.
We are happy to see that chemical science, in its recent eminent advancement, has
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St. Louis lffed. and Surg. Journal, Sept. 10, 1869.
It is altogether the best text-book now in hand for the student of chemistry.-Pacigfc Med. and Surg. Journal, Sept. 1869.
If the student of medicine can afford but one text-book on chemistry, we advise
him to give Fownes' the preference.-N. Y. Med. Record, Sept. 1, 1869.
HENRY C. LEA, Philadelphia.




PRACTICAL HANDBOOK
OF
MEDICAL CHEMISTRY.
BY
JOHN E. BOW MAN, F.C.S.,
FORMERLY PROFESSOR OF PRACTICAL CHEMISTRY IN KING'S COLLEGE, LONDO'.
EDITED BY
CHARLES L. BLOXAM,
PROFESSOR OF PRACTICAL CHEMISTRY IN KING'S COLLEGE, LONDO}T,
FIFTH AMERICAN
FROM THE FOURTH AND REVISED LONDON EDITION.
WITH ILLUSTRATIONS.
PHILADELPHIA:
II E N R Y C. L E A.
1870.




PITILADELPHTA:
COLLINS, PRINTER, 705 JAYNE STREET.




PREFACE
TO THE FOURTH EDITION.
DURING the seven years which have elapsed since
the publication of the third edition of this work,
considerable advances have been made in the practical part of Medical Chemistry.
The Editor has endeavored to represent these
as fully as is consistent with the concise and simple
character which constitutes one of the great merits
of Bowman's "Handbook," always remembering
that the processes described should be such as can
be carried out by the medical student, with the
resources of the medical school and the hospital.
In the chapters on the Analysis of Urine, where
the greatest services are rendered by chemistry to
clinical medicine, processes have been introduced
for the quantitative determination of kreatinine
and of ammonia, and the methods of determining
them have been carefully revised at the laboratory
1*.




Vi                PREFACE.
table. The application of the volumetric principle
to the analysis of urine has been extended as far
as it appears to be safe, since the rapidity with
which volumetric determinations may be executed,
with great relative accuracy, and without demanding great skill on the part of the analyst, recommends this method strongly to the attention of the
medical practitioner.
Short practical directions for the examination of
the solid excrements, of bile, and of the liquids of
muscular flesh have been added; but chyle, lymph,
&c. have been omitted, as not generally obtainable
for analysis.
Much improvement remains to be made in the
difficult examination of mixed fluids for the proximate constituents of animal bodies, through the
recent researches of English and Continental chemists have enabled the editor to make some additions, which, it is hoped, will prove useful.
Since the examination for poisons in organic
mixtures is comparatively seldom undertaken,
except by the professional chemist, the additions
which have been made to that part of the work
presuppose considerable familiarity with chemical
manipulations; though it has not been forgotten
that, for the purposes of a judicial inquiry, the




PREFACE.                  Vii
medical man often requires a knowledge of the
best processes for the detection of poison, though
not desiring to carry them out himself.
Believing that the revival of the electrolytic
method for the detection of metallic poisons will
give greater confidence in chemico-legal investigations, the editor has fully described its application.
Short chapters have been added upon the detection of strychnia, nicotia, phosphorus, and alcohol,
in organic mixtures.
The general systematic course for the detection
of poisons in organic mixtures has been tested by
mixing minute quantities of the poisonous substances to which it refers with articles of food, and
proving that the directions given would certainly
lead to their detection.
The concluding chapter contains some concise
directions for the application of the elegant process of dialysis, introduced by Professor Graham,
to the separation of poisons from organic mixtures.
KING'S COLLEGE, LONDON,
October, 1862.








PREFACE
TO THE THIRD EDITION.
THE rapid sale of two large editions of this little
work encourages me to hope that I was not altogether unsuccessful in supplying a deficiency in
medical literature which has been long felt by a
large body of the Profession, as well as in furnishing a plain and trustworthy text-book for the
Medical Student.
In the present edition I have endeavored, without materially adding to it, to embody all the
recent discoveries in Medical Chemistry which have
been announced up to the present time, and thus
to keep pace with the rapid advance which is every
year being made in this most important branch of
medical science.
JOHN E. BOWM![AN.
KING'S COLLEGE, LONDON,
January, 1855.








PREFACE
TO THE FIRST EDITION.
THE want which, as a teacher of Practical Chemistry in a Medical School, I have long felt, of a
small manual containing instructions for the examination and analysis of urine, blood, and a few
other of the more important animal products, both
healthy and morbid, and comprising also directions
for the detection of poisons in organic mixtures
and in the tissues, was my chief inducement in
undertaking to write the present little work.
In doing this, my endeavor has been to supply a
book that will be found useful, not only to the
Medical Student, but also to the Practitioner, to
whom the value and importance of the applications
of modern chemistry and microscopic analysis to
his art are becoming daily more and more apparent.
The writers to whom I have been chiefly indebted
are Drs. Golding Bird, Owen Rees, Day, Franz




xii                PREFACE.
Simon, Vogel, and Donne My warm acknowledgments are also due to my friend and colleague,
Professor Miller, who, in addition to much other
valuable assistance, kindly undertook to revise the
proof-sheets during their passage through the
press.
J. E. BOWMAN.
KING'S COLLEGE, LONDON,
April, 1850.




CONTENTS.
PA R T I. -URINE.
CHAPTER I.
PAGE
HEALTHY URINE......      25
The extraction, composition, and properties of the several
constituents of healthy urine; Urea, Uric Acid, Hippuric
Acid, Kreatinine, Mucus, Extractive and Coloring Matters,
Ammoniacal Salts, Fixed Alkaline Salts, and Earthy Salts.
Quantitative Determination of Kreatinine.
Separation of Indigo-blue from Healthy Urine.
CHAPTER II.
QUANTITATIVE ANALYSIS OF HEALTHY URINE...      48
Determination of Water, Urea, Uric Acid, and Salts.
Determination of Ammonia.
Quantitative Analysis of the Ash of Urine.
Determination of Alkaline and Earthy Phosphates, Sulphuric
Acid, and Chlorine in the Original Urine.
Volumetric determination of Phosphates in Urine.
Determination of the degree of Acidity.
CHAPTER III.
AVERAGE COMPOSITION OF HEALTHY URINE..            61
Results obtained by Berzelius, Simon, Miller, Marchand, Lehmann, and Becquerel.
CHAPTER IV.
MORBID URINE.......      63
Detection of Abnormal proportions of Urea, Uric Acid, Urate
of Ammonia, Urate of Soda, Hippuric Acid, Mucus, Coloring
Matters, and Salts.
Urine containing Sugar. Tests for Sugar proposed by Trommer, Maumen6, Moore, Bottger, and Briicke. Fermentation
Test.
Detection of Sugar in Healthy Urine.
2




xiv                     CONTENTS.
PAGE
New substance, Alkcapton, simulating Sugar in Urine.
Albuminous Urine. Detection of Blood in Urine.
Urine containing Biliary Matter. Pettenkofer's, Heller's, and
Gmelin's Tests for Bile.
Presence of Pus, Fatty and Chylous Matter, Kiestein, and Semen in Urine.
Detection of Oxalate of Lime, Cystine, &c., in Urine.
CHAPTER V.
EXAMINATION OF URINE SUSPECTED TO CONTAIN EITHER AN UNNATURAL
PROPORTION OF SOME ONE OR MORE OF THE USUAL INGREDIENTS, OR
ELSE SOME ABNORMAL MATTER...                   94
Quantitative Estimation of Urea by Liebig's process.
Methods of determining Urea proposed by Leconte and E.
Davy.
CHAPTER VI.
EXAMINATION OF MORBID URINE, THE NATURE OF WHICH IS ALTOGETHER UNKNOWN......      122
Identification of Urinary Deposits.
Systematic Examination of the Clear Urine.
Microscopic Examination of Urinary Deposits.
CHAPTER VII.
QUANTITATIVE ANALYSIS OF DIABETIC URINE...     137
Volumetric Determination of Sugar by an Alkaline Solution
of Tartrate of Copper.
Analyses of Diabetic Urine by Simon, Percy, and Bouchardat.
CHAPTER VIII.
QUANTITATIVE ANALYSIS OF ALBUMINOUS URINE.            146
Analyses of Albuminous Urine by Simon and Percy.
PART I.- CALCULI AND CONCRETIONS.
CHAPTER 1.
URINARY CALCULI                                           150
Identification of Calculi composed of Uric Acid, Xanthine,
Urate of Ammonia, Phosphate of Lime, Triple Phosphate,
Oxalate of Lime, Urate of Lime, or Cystine.




CONTENTS.                          XV
CHAPTER II.
PAGE
SYSTEMATIC COURSE FOR THE EXAMINATION OF CALCULI, THE COMPOSITION OF WHICH IS UNKNOWN....      159
CHAPTER III.
BILIARY CALCULI OR GALL-STONES....      163
Composition and properties of Cholesterin.
Thudichuma's process for the Analysis of Biliary Calculi.
CHAPTER IV.
G{OUTY CONCRETIONS......      164
Qualitative Analysis of Gouty Concretions.
CHAPTER V.
SOLID EXCREMENTS....                         167
Marcet's process for Separating the Proximate Principles contained in the Feces.
Excretine and Excretolic Acid.
PART III.- BLOOD.
CHAPTER I.
HEALTHY BLOOD...                          169
General Characters of Blood
Separation of its Proximate Constituents; Blood Corpuscles,
Albumen, Fibrine, Extractive, Fatty and Saline Matters.
Recognition of Blood-stains on Textile Fabrics, and on Iron.
Extraction and Properties of Huemuatin.
Huematoidin. Blood crystals.
CHAPTER II.
QUANTITATIVE ANALYSIS OF BLOOD...             190
Analysis of Coagulated and Uncoagulated Blood.
Average Composition of Healthy Blood.
Results obtained by Dumas, Simon, Becquerel and Rodier,
Lehmann and Enderlin.
CHAPTER III.
MORBID BLOOD......      210
Detection of Abnormal Proportions of Water, Corpuscles, Albumen, Fibrine, Fatty Matter, Cholesterin, Urea, and Salts.
Blood containing Sugar, Biliary Matter, Pus, and Animalcules.




Xvi                     CONTENTS.
PART  IV. —MILK, BILE, MUCUS, PUS, &c.
CHAPTER I.
PAGE
MraK.....                          224
General Characters of Milk.
Extraction and Identification of the Caseine, Lactine, Fat and
Saline Matters in Milk.
Composition of Human Milk, according to Simon, Clemm,
Chevalier and Henri, Vernois and Becquerel.
Composition of the Milk of other Animals.
Results obtained by Chevalier and Henri, and by Morin.
Galactine.
CHAPTER II.
QUANTITATIVE ANALYSIS OF MILK.                          232
Volumetric Determination of Lactine.
CHAPTER III.
MILK DURING DISEASE.
Composition of the Colostrum.
CHAPTER. IV.
THE ADULTERATIONS OF MILK.....      236
Detection of Starch, Gum, Annato, &c.
Use of the Lactometer.
Daubrawa's process for the Valuation of Milk.
CHAPTER V.
BILE.......      239
Composition of Bile.
Extraction and Properties of Cholic and Choleic Acids.
Taurine. Biliverdine. Biliphaeine.
Sugar-forming Substance in the Liver.
CHAPTER VI.
JUICE OF FLESH......      242
Preparation and Properties of Kreatine.
Kreatinine. Sarcine. Inosite.
Extraction of Sarco-lactic and Butyric Acids from Juice of
Flesh.




CONTENTS.                       XVii
CHAPTER VII.
PAGE
Mucus.....      245
Quantitative Estimation of its Proximate Constituents.
Morbid Conditions of Mucus.
CHAPTER VIII.
Pus........      249
General Characters and Quantitative Analysis of Pus.
Blue Pus. Pyocyanine.
CHAPTER IX.
BONE.......             254
Quantitative Analysis of Bone.
Chancel's process for the Determination of Phosphoric Acid.
Analyses of Bone, by Von Bibra and Berzelius.
Diseased Bone. Analyses by Lehmann, Prbsch, Valentin, and
Von Bibra.
CHAPTER X.
EXAMINATION OF MIXED ANIMAL FLUIDS....      263
General Processes for the detection of Fibrin, Albumen, Caseln,
Pyin, Pus, Mucus, Gelatine, Chondrin,'Blood, Biliary Matter, Urea, Kreatine, Inosite, Kreatinine, Fat, Cholesterin,
and Serolin, Milk, Sugar, Ammonia, Uric Acid, Taurine,
Leucine, and Tyrosine.
Systemnatic Examination of Mixed Fluids for the proximate
Constituents of Animal Bodies.
PART V. -THE DETECTION OF POISONS IN
ORGANIC MIXTURES, &c.
CHAPTER I.
ARsENIC...                                 274
Identification of Arsenious Acid when in the pure state.
Marsh's and Reinsch's tests. Examination of the Copper
and Hydrochloric Acid for Arsenic.
Detection of Arsenic in Organic Liquids, which are pretty
clear and homogeneous.
Electrolytic test for Arsenic.
Detection of Arsenic in the contents of a Stomach, Vomited..4




Xviii                   CONTENTS.
PAGE
Matters, &c., and in the Tissues and other solid Organic
Matters.
Detection of Arsenite of Copper in Paper Hangings, &c.
Quantitative Determination of Arsenic in other Mixtures.
CHAPTER II.
ANTIMONY.......      292
Identification of Tartar Emetic.
Electrolytic tests for Antimony.
Detection of Antimony in the presence of Organic Matters.
Quantitative Determination of Antimony.
CHAPTER III.
MERCURY.......      294
Detection of Mercury in Organic Mixtures.
Lassaigne's process for identifying minute Sublimates of
Mercury.
Electrolytic tests for Mercury.
Detection of Mercury in the Tissues.
CHAPTER IV.
LEAD........      298
Examination of Water suspected to contain Lead.
Detection of Lead in Organic Mixtures and in the Tissues.
CHAPTER V.
COPPER.......      304
Detection of Copper in Organic Mixtures and in the Tissues.
Electrolytic test for Copper.
Quantitative Determination of Copper in any Organic Mixture.
CHAPTER VI.
ZINC........      307
Examination of Organic Matters for Zinc.
CHAPTER VII.
IODINE.......      309
Detection of free and combined Iodine in Organic Mixtures.




CONTENTS.                         Xix
CHAPTER VIII.
PAGE
SULPHURIC ACID......      311
Detection of Sulphuric Acid in Organic Mixtures; and in
Stains on Clothing.
Detection of " Sulphate of Indigo" in Organic Mixtures.
CHAPTER IX.
HYDROCHLORIC ACID......      313
Detection of Hydrochloric Acid in Organic Mixtures.
Quantitative Determination of Hydrochloric Acid.
CHAPTER X.
NITRIC ACID.......      315
Examination for Nitric Acid in Organic Mixtures; and in
Stains on Clothing.
CHAPTER XI.
OxALIC ACID.......      317
Separation of Oxalic Acid from Organic Mixtures. - Ideltification and Quantitative Determination.
CHAPTER XII.
HYDROCYANIC OR PRUSSIC ACID....      319
Detection of Hydrocyanic Acid in Organic Mixtures. Tests
applicable to the Vapor. Liebig's test. Henry and Hurmbert's test. Prussian Blue test.
Quantitative Determination of Hydrocyanic Acid.
CHAPTER XIII.
OPIUM.......      325
Examination of Organic Mixtures and Tissues for Morphia
and Meconic Acid. Identification of Morphia.
CHAPTER XIV.
STRYCHNIA.....                         328
Processes for the detection of Strychnia in Organic Mixtures,
Tissues, &c. Extraction of Strychnia by Ether, Chloroform, and Benzole.




X X                     CONTENTS.
CHAPTER XV.
PAGE
NICOTIA.......      330
Extraction of Nicotia from Organic Mixtures. Identification.
CHAPTER XVI.
PHOSPHORUS..     331
Detection of Unoxidized Phosphorus in Organic Mixtures.
Examination for Phosphorous Acid resulting from the
Oxidation of the Phosphorus.
CHAPTER XVII.
ALCOOL......     333
Extraction of Alcohol from Organic Mixtures; its Identification.
CHAPTER XVIII.
GENERAL SYSTEMATIC COURSE FOR THE DETECTION OF POISONS IN
ORGANIC MIXTURES......      334
1. The Poison is believed to be Metallic. Systematic Examination' for Arsenic, Antimony, Mercury, Copper, Lead, Zinc,
Barium, Silver, Bismuth.
2. The Poison is believed to be Organic. Systematic Examination for Oxalic Acid, Morphia, Strychnia, Nicotia, and
Conia.
3. Nothing is known of the Nature of the Poison.
CHAPTER XIX.
SEPARATION OF POISONS FEROMI ORGANIC MIXTURES BY DIALYSIS.  339
WEIGHTS AND MEASURES,..                     o            341
INDEX......     343




LIST OF ILLUSTRATIONS.
FTGURE.                                                         PAGE
1. Oxalate of Urea......     30
2. Nitrate of Urea......      30
3. Uric Acid.......     32
4. Hippuric Acid......     35
5. Mucus and Epithelium.....     38
6. Evaporated Residue of Healthy Urine...     42
7. Mixed Phosphates......     44
8. Prismatic Crystals of Triple Phosphate...     45
9. Penniform Crystals of Triple Phosphate...     45
10. Stellate Crystals of Triple Phosphate...     46
11. Urate of Ammonia....             65
12.   "         "     with Spicula....      66
13.   "   of Soda......      67
14. Crystallized Phosphate of Lime....     70
15. Fermentation Test for Sugar....      76
16. Toru]la Vesicles......     78
17.   "   Stem......      78
18. Fibrinous Cast......      82
19. Blood in Urine......      83
20. Pus in Urine......      85
21. Large Organic Globules.....     86
22. Small Organic Globules.....      86
23. Spermatozoa and Spermatic Granules...     88




Xxii             LIST  OF  ILLUSTRATIONS.
FIGURE.                                                         PAGE
24. Octohedra of Oxalate of Lime....      90
25.     "'    "        "  seen when dry..      90
26. Dumb-bells of Oxalate of Lime....      91
27. Rosettes of Cystine....             92
28. Hexagonal Crystals of Cystine....     92
29. Chloride of Sodium simulating Cystine...      92
30. Nitrate of Urea......      95
31. Pipette.......      98
32. Burette.......      98
33. Leconte's Apparatus for determining Urea..    101
34. Crystalline Forms of Uric Acid....    104
35.     "....    105
36. Chloride of Sodium.....    107
37. Hippuric Acid......    108
38. Mixed Phosphates.                                           112
39. Pus Corpuscles..                          117
40. Urinometer......   123
41. Triple Phosphate (Stelle).....    133
42.   "       "      (Prismatic)....    133
43. Crystalline Forms of Uric Acid....    133
44. Octohedra of Oxalate of Lime....    133
45. Dumb-bells of Oxalate of Lime....   133
46. Rosettes of Cystine.....    134
47. Hexagonal Plates of Cystine....    134
48. Urate of Soda......    135
49. Fat in Urine......    135
50. Mucus and Epithelium.....    135
51. Pus in Urine......    135
52. Blood in Urine......    135
53. Spermatozoa, &c......    135
54. Apparatus for the Estimation of Sugar in Urine.           138
55. Alternating Calculus....   151
56. Uric-Acid Calculus.....    151
57. Urate of Ammonia Calculus,...    153




LIST  OF  ILLUSTRATIONS.                     xxiii
FIGURE.                                                         PAGE
58. Phosphate of Lime Calculus...           154
59. Fusible Calculus....           156
60. Oxalate of Lime Calculus.                                  156
61. Biliary Calculi......    163
62. Cholesterin....    164
63. Blood Corpuscles in strings...           172
64.   "      "       detached...           172
65.   "      C"      collapsed...           174
66. White Corpuscles of the Blood...           178
67. Fat in Blood......    215
68. Cholesterin......         216
69. Milk Globules......    227
70. Colostrum Corpuscles.....   228
71. Pus in Milk......    235
72. Blood in Milk......    235
73. Starch Granules......   237
74. Pus Corpuscles......    251
75. Apparatus for the Estimation of Carbonic Acid..   260
76. Arsenious Acid......   275
77. Crust of Reduced Arsenic...           276
78. Apparatus for Marsh's Test...           277
79.     "            "     "....    278
80. Small Marsh's Apparatus for Minute Testing.             279
61. Electrolytic Apparatus.....    284
82. Apparatus for Dialysis.....    339








MEDICAL
CHE MISTRY.
PART I.
CHAPTER I.
HEALTHY URINE.
SECTION I.
1. HEALTHY human urine is an amber-colored, watery
fluid, holding in solution a great variety of substances,
both organic and inorganic, and containing also in suspension a small quantity of mucus, derived from the
bladder and urinary passages.  The specific gravity
(278) of the healthy secretion may be said to vary from
1003 to 1030, depending on the amount of solid and
liquid food taken, the period of the day at which the
urine is passed, and other circumstances which tend to
increase or diminish the proportion of solid matter contained in it. Thus the urine which is passed shortly
after drinking. much water or other fluid, commonly
called urina potus, is usually pale in color, and of low
specific gravity, varying from 1003 to 1009; while, on
the other hand, that which is secreted soon after the
digestion of a full meal, commonly called uiriia chyZi,
has most commonly a high specific gravity, frequently
1030;- the urine which is passed immediately after a
night's rest, called urina sanguinis, may generally be
considered to furnish a fair specimen of the average
3




26               HEALTHY URINE.
density of the whole urine, and will in most cases be
found to have a specific gravity varying from 1015 to
1025. The average density of the whole urine passed
by an individual in the twenty-fours hours is usually from
1015 to 1020; and the quantity passed during the same
period varies from twenty to forty-eight or fifty ounces,
holding in solution usually from 600 to 700 grains of
solid matter (279).
2. While warm, urine has a slightly aromatic smell,
which is not perceptible after cooling. It is usually
slightly acid to test-paper, from the presence of acid
phosphate of soda (NaO,2HO,PO,) but the experiments
of Dr. Bence Jones show that when passed shortly after
eating, the urine is often neutral, or even alkaline, becoming again gradually more and more acid, up to the
time when the next meal is taken.'When kept for some
little time, it first becomes a little more acid (apparently
from the formation of little lactic and acetic acids), and
deposits of a few crystals of uric acid entangled in the
cloudy deposit of mucus; but after, a longer period it
putrefies, becoming alkaline and ammoniacal, and deposits a sediment of earthy phosphates, previously held
in solution by the free acid (43). If the urine be kept
for a still longer time, it becomes more and more concentrated by. spontaneous evaporation, deposits minute
crystals of chloride of sodium, phosphates, and other
salts, and eventually becomes covered with a grayishcolored mould, containing minute fungi and animalcules.
3. Although chemists have not yet succeeded in insulating for examination all the ingredients of urine, nor
even in ascertaining the general nature and character of
several of the compounds which probably enter into its
composition, still they have, by their researches, determined what appear to be the most important of: its constituents; and it is to these only that the student need
turn his attention, leaving the more problematical and
obscure parts of the subject to be decided by the future
labors of the physiological chemist.
4. The solid matters of the urine may be said to consist of the following —viz., Urea; uric acid; hippuric acid;
kreatinibze; grape sugar; vesical m ucus, and epithelial debris;




UREA.                        27
animal extractive; ammoniacal salts; fixed  aline salts;
and earthy salts.*
5. The student will do well to test a little of the healthy
secretion, which should, for this purpose, be that passed
immediately after a night's rest (1), for these several substances, in the manner described under each, in the following sections; and if he has leisure and opportunity,
he may prepare specimens of urea, uric and hippuric
acids, and some of the other constituents.
SECTION It.
Urea (C0H4N,20).
6. This important ingredient of the urine, which appears to be the vehicle by which nearly the whole of the
nitrogen of the exhausted tissues of the body is removed
from the system, is a solid crystalline substance, colorless
when in a state of purity, and easily separated firom the
other matters with which it is associated.
7. The presence of urea in the urine may be readily
shown by concentrating a little of the secretion to about
one-half or one-third its bulk, and mixing it with aa
equal quantity of pure nitric acid; when delicate crystalline rhomboidal plates of impure nitrate of urea (C2H4
N 202,HO,NO,) will be found gradually to separate from
the liquid (16).
8. Pure urea may be obtained from the nitrate thus
separated.  For this purpose, about a pint of urine,
filtered from the mucus as soon as possible (11), is evaporated, at a heat below its boiling point, to two or three
ounces; when cool, the concentrated urine is decanted
from the deposited salts, and mixed with an equal bulk
of colorless nitric acid (sp. gr. 1'25). After standing for
some time, the pasty mass of nitrate of urea is pressed, to
free it from the adhering liquid, dissolved in a little boiling
water, and allowed to crystallize.  The pure crystals are
again dissolved in hot water, and finely powdered carbonate of baryta is added in small portions, as long as
* According to Campbell, urine also contains a minute quantity of
formic acid (C2H204).




28               HEALTHY  URINE.
any effervescence is perceptible.  The nitric acid has
now combined with the baryta, whilst the carbonic acid,
being incapable of combining with the urea, makes its
escape.
Nitrate of urea.  Carb. ba.ryta.   Urea.  Nitrate baryta.
C2H4N202,HO,N05 + BaO,CO2 = C2H4N202 + BaO,NO5 + HO +CO2.
The excess of carbonate of baryta is separated by
filtration, and the clear liquid evaporated to dryness on
the water-bath.  The dry residue of urea and nitrate of
baryta is boiled with a little alcohol, which dissolves only
the urea, and, when decanted off and evaporated, deposits
it in prismatic crystals resembling nitre, which may be
purified, if necessary, by dissolving in water, decolorizing with animal charcoal, and evaporating the filtered
solution.
9. The crystals of urea, which, when obtained by slow
evaporation, are four-sided prisms, and deliquesce slightly
in air, are soluble in about their own weight of cold
water, and in a much smaller quantity of hot; from
which latter the urea separates, on cooling, in the form
of beautiful silky needles.  It is soluble in about 4'5
parts of cold alcohol, and in less than half that quantity
of hot; in cold ether it is nearly insoluble.  Its taste is
saline and cooling, somewhat resembling that of nitre.
10. The proportion of urea present in healthy urine
appears to vary from twelve to upwards of thirty parts
in 1000, about fourteen or fifteen being the average.
11. An aqueous solution of urea may be kept, provided it is pure and tolerably concentrated, for a considerable length of time, without undergoing chemical
change; but if any albumen or mucus, or other fermentescible matter, is present, decomposition rapidly sets in,
and in a short time the whole of the urea becomes
transformed into carbonate of ammonia:(Nt40, CO2), the
elements of water being at the same time assimilated.
C2 4N 02+4rH0=2(NH40,  002).
In urine, this change speedily takes place, owing to the
presence of mucus; the secretion thus acquiring, especially
in warm weather, an alkaline reaction in the course of a




UREA.                       29
few  hours after being passed.  Under the influence of
the caustic alkalies, also, urea becomes gradually converted into carbonic acid and ammonia.
12. When heated on platinum foil to about 250~, urea
fuses without undergoing decomposition; but if the heat
be increased much beyond that point, it is decomposed
into ammonia (NH3) and carbonate of ammonia (NE140,
C02), which volatilize, leaving a residue consisting chiefly
of melanuric acid (C,E14N404).
13. Urea, though its solution is neutral to test-paper,
has decidedly basic characters, combining with acids t(,
form salts, some of which are crystalline.- Of these, the
two which are of the mlost practical importance are the
oxalate (C2H-,4N202,IH0,020) and the nitrate (C024N202,
H0,NO,), which on account of their sparing solubility
in water, supply a ready means of separating urea from
the other matters coexisting in the urine.
14. Oxalate of urea (C2HE4NO02,HO C,,03) may be prepared by concentrating urine on a water-bath to about
one-eighth its bulk, and filtering through- muslin, in order
to separate the insoluble sediment of phosphates and
urates, which are generally deposited during the evaporation. The liquid thus clarified is mixed with about an
equal bulk of a strong solution of oxalic acid in hot
water, or the solid acidt in powder may be added as long
as the liquid, heated to about 190o or 2000, continues to
dissolve it.  The mixture, on codoling, deposits an abundant crop of crystals of oxalate of urea, mixed with a
little of the excess of oxalic acid, and colored brown by
the adhering impurities. The crystals are then gently
pressed between folds of filtering paper, washed with a
small quantity of ice-cold water, and purified by recrystallization; the last traces of coloring matter being
removed, if necessary, by boiling the solution with purified animal charcoal.t
* The bibasic character of oxalic acid being now generally recognized, the formula of oxalate of urea should be written 2(C2H4N202),
2HO,C406,
t Animal charcoal is purified from the phosphate and carbonate of
lime by repeatedly boiling it with hydrochloric acid, till the acid
liquid is not precipitated by ammonia; the charcoal must then be
washed with water till the latter is no longer acid.
k*




30                HEALTHY  URINE.
Fig. 1.          15. The oxalate thus obtained is
colorless, and in the form of tabular
or prismatic crystals (Fig. 1), which
are readily soluble in hot water, but
only sparingly so in cold, twentyfive parts of which dissolve not more
than one part of the salt.
The oxalate of urea obtained from
Oxalate of Urea.  urine may be employed to furnish
pure urea, by dissolving it in hot
water, and adding powdered chalk as long as it causes
effervescence. The insoluble oxalate of lime is then
filtered off, and the solution of urea evaporated on a
water-bath to crystallization.
Oxalate of urea.   Carb. lime. Oxal. lime.   Urea.
C2H4N202,HO,C203 +- CaO,CO2 - CaO,C203+ C2H4N02 +- HO + CO2.
16. Nitrate of urea (C2HIN202,I IO,NO0) may be robtained
by adding strong, colorless nitric acid, free from nitrous
acid, to urine previously concentrated by evaporation to
about one-third its bulk; the nitrate gradually separates
in irregular rhomboidal plates
Fig. 2.        (Fig. 2), more or less colored and
modified in form by the impuri.
ties present.  The crystals are
washed with a little ice-cold water,
then  pressed  between folds of
filtering paper, and redissolved in
lukewarm water; lastly, they are
purified by recrystallization, and,
if necessary, the last traces of
coloring matter may be removed
by boiling the solution with purified animal charcoal.
=-By,,___"  The absence of nitrous acid in
the nitric acid employed for preNitrate of Urea.  cipitating the urea is insisted on
because this substance is immediately decomposed by nitrous acid, with violent efierveseence, from escape of carbonic acid and nitrogen.




URIC (OR LITHIC) ACID.              31
C2H4N202+2NO3=2CO- N4+ 4HO.
Even with colorless nitric acid, a slight effervescence
always takes place, since a little nitrous acid is formed
by the action of urinary coloring matter upon the nitric
acid.
17. Nitrate of urea is soluble in about eight times its
weight of cold water, and in a much smaller quantity of
hot. It is tolerably soluble also in alcohol, especially
when warm; but almost insoluble in ether.
18. The formation of this crystalline compound on the
addition of nitric acid, is one of the most distinctive tests
for the presence of urea which we possess. The experiment is made easily, and with great delicacy, under the
microscope, by concentrating a drop or two of urine on
a glass slide, and adding to it about an equal quantity of
pure nitric acid; the nitrate will gradually crystallize in
delicate rhomboidal plates (Fig. 2), the number and
abundance of which will furnish some indication of the
quantity of urea present in the secretion (181).
SECTION III.
Uric (or Lithic) Acid ( CoHNO4  = 2 O, C10I2N4 04).
19. Uric acid, though usually present only in small
quantity in human urine, appears to be one of the most
important of its ingredients; and as the pr6portion varies
considerably in many forms of disease, its determination,
when in abnormal quantity, frequently affords much
valuable assistance to the physician in diagnosis. The
proportion present in the healthy secretion appears to
vary from 0'3 to nearly 1'0 in 1000 parts, about 0'4 being
the usual average. It probably exists, for the most part,
in combination with alkalies, since, when uncombined, it
requires nearly 15,000 times its weight of cold water to
dissolve it, while the alkaline urates are considerably
more soluble (22.)
20. Uric acid may be obtained by adding to urine, previously concentrated to about half its bulk, a few drops
of hydrochloric acid (IfC1l), and allowing the mixture to




32                HEALTHY  URINE.
stand for a few hours in a cool place.*  Minute relddish
crystals of the acid gradually appear, having the fo)rms
shown in Fig. 3, stained with the coloring matters co-existing in the urine. These crystals may then be dissolved
in moderately dilute potash, and
Fig. 3.       from the solution thus obtained-the
pure acid may be again precipitated
~:~.:~,.~       in a crystalline and colorless state,
by supersaturating it with hydrog~~    S)O  chloric acid.
21. The crystalline forms in which
uric acid is presented to us are very
V    a  im various (186), but they all appear to
be  modifications  of the  rhombic
Uric Acid.     prism. Most of these crystals, when
examined with the polarizing microscope, develop very beautiful colors; and their forms are
frequently characteristic, and indicative of the peculiar circumstances under which they may have been deposited.
22. Uric acid requires, according to Liebig, about
15,000 times its weight of cold, and nearly 2000 times
its weight of hot water to dissolve it, forming, in the
latter a solution which is feebly acid to test-paper. It
is insoluble in alcohol, and nearly so in dilute hydrochloric and sulphuric acids; it dissolves in the latter acid
when concentrated, and is reprecipitated on the addition
of water.  It combines with bases, especially the alkalies
and alkaline earths, forming salts (urates), which are for
the most part insoluble, or very sparingly soluble in
water.  Of these the most soluble is the urate of potash
(2K1O,CoH2N N), whi'ch dissolves in about 35 times its
weight of hot water. On this account, uric acid dissolves
with comparative facility in a dilute solution of potash.
Urate of soda (2NaO,C,,H2N404) requires for its solution
124 times its weight of hot water; and urate of ammonia
(NH140,HO,CI0H2N404) 243 times its weight of hot, and
about 1720 of cold water, to effect its solution. The
presence of a small quantity of chloride of sodium, such
* Even without previous concentration, urine will generally deposit
crystals of uric acid, if mixed with a little hydrochloric acid and set
aside.




HIPPURIC ACID.                    33
as is contained in the urine, renders water capable of
dissolving nearly twice as much urate of ammonia as is
taken up by pure water?.*
23. The action of nitric acid (HO,N05) upon uric acid
is highly characteristic, and furnishes, perhaps, the most
delicate test of its presence which we possess.  If a little
of the acid, in the state of powder, is placed in a drop or
two of tolerably strong nitric acid, in a watch glass or
on a strip of glass, it will gradually dissolve: carbonic
acid (CO2) and nitrogen being given off with effervescence, and leaving behind a mixture of alloxant (C8-H4
N201,o), alloxantine (CsY-fN20,,), urea, and some other
compounds. This may then be evaporated nearly to
dryness at a gentle heat, when a red residue will be left,
which, when cold, should be moistened by a drop or two
of ammonia, or exposed to ammoniacal fumes, which will
develop a beautiful purplish red color, owing to the formation of murexide (CG21T6N508).  If the mass be now
moistened with solution of potash, a very beautiful purple
color will be produced. The potash may be applied at
once to the residue left after evaporating the nitric acid,
and is a far:more delicate and characteristic test than the
ammonia.  The same effect is produced when urate of
ammonia, or any other urate, is similarly treated.
24. When heated before the blowpipe, uric acid is
decomposed, emitting a disagreeable smell, resembling
that of burnt feathers, mixed with that of hydrocyanic
acid, which, together with carbonate of ammonia and
some other compounds, is formed during the decomposition.
SECTION IV.
Hippuric Acid (HO,C,,0HN05).
25. A small quantity of hippuric acid appears to be
generally present in healthy urine, and in certain forms
of disease, especially in cases where a vegetable diet has
* Lithia forms one of the most soluble urates. Schilling has shown
that the acid urate of lithia (LiO,HO,C,0H2N40,) dissolves in 39 parts
of boiling water, and 368 parts of cold water. The neutral urate
would be still more soluble.. t Alloxan has been found by Liebig, on one occasion, in mucus
from the intestines.




34:                HEALTHY  URINE.
been adopted, the quantity is found to increase considerably.*  In jaundice according, to Kiihne, hippuric acid
is entirely absent from the urine, even after the administration of benzoic acid, which is converted, in the normal
state of the system, into hippuric acid.
26. Hippuric acid may be prepared from fresh human
urine, or still more readilyfrom the urine of the herbivora,
which usually contains it in much larger quantity than
the human secretion. The urine is first evaporated at a
gentle heat until it has the consistence of a syrup; it is
then, after cooling, supersaturated with hydrochloric acid,
which will dissolve the earthy salts, and cause after a
time a crystalline precipitate of impure hippuric acid
mixed with uric acid, coloring matters, and other substances, which give a more or less dark brown or reddish
color. The precipitate is then dissolved in a small
quantity of hot water, from which it again crystallizes
on cooling. To obtain the pure; acid, these crystals may
be boiled with hydrate of lime- and water, the solution
of hippurate of lime (CaO,C,8H,1NO5), filtered and mixed
with excess of hydrochloric acid, which precipitates the
hippuric acid, in the form. of minute tufts of needle-shaped
crystals (Fig. 4, a and b);. these may be again dissolved in
hot water, and allowed to cool gradually, when beautiful
crystals (four-sided prisms) will be obtained of considerable length, but so friable as to'fall into powder under
the slightest pressure. A morre minute examination for
hippuric acid in human urine may be made by evaporating eight or ten ounces of urine to a syrup, acidulating
with  hydrochloric acid, and agitating with about an
equal volume of ether, the separation of which is afterwards promoted by adding a little alcohol. If the solution
* According to Licke, hippuric acid is often entirely absent from
the urine of persons living upon a mixed diet, and can only be detected
when the food is composed chiefly of vegetables. It is said to increase
in fever, in chorea, and in diabetes.  Dr. Bence Jones has recently
determined the hippuric acid in the urine of two healthy men living
upon a mixed diet. A large number of experiments led to the mean
result that, in one case, the urine of 24 hours (1-25 pint) contained
4'96 grs. of hippuric acid, and in the other (2'37 pints) 6'5 grs., the
quantities of uric acid passed in the same time being, respectively,
4-74 and 11'6 grs.




HIPPURIC ACID.                   35
in ether be evaporated, and the residue boiled with a
little water, the hippuric acid will be dissolved, and deposited in crystals, when the solution is allowed to stand.
Fig. 4.
Hippuric Acid.
27. lHippuric acid is very sparingly soluble in cold
water, requiring about 400 times its weight to dissolve
it; in hot water, however, it is readily soluble, and, on
cooling, crystallizes in beautiful silky tufts. It is very
soluble in alcohol, but very slightly in ether.*
28. When mixed with uric acid, it may-be separated
from that substance by treating the mixture either with
hot water or alcohol, in both of which uric acid is insoluble or nearly so (22). It may be distinguished from
uric acid also, by its giving no purple color when tested
with nitric acid and ammonia (23), and by its different
crystalline form (26, 29, 186).
29. When an alcoholic solution of hippuric acid is
allowed to evaporate slowly, the crystalline residue which
is left has usually some such appearance as that shown
in Figure 4, c. When deposited from a hot aqueous
solution, the crystals have more the appearance shown
at d in the figure.
30. When heated in a tube, it is converted chiefly into
benzoic acid (HO,C1,H,,03), and benzoate of ammonia
(N 140,014H103), which sublime, together with a red oily
matter (benzonitrile, C,4,HN), which has a peculiar and
characteristic smell, resembling that of the Tonka bean.
* Thus distinguished from benzoic acid, which dissolves readily in
ether.




361                HEALTHY URINE.
When boiled with acids or alkalies, hippuric acid is converted into benzoic acid and glycocine (gelatine sugar):
Hippuric acid.       Benzoic acid.   Glycocine.
H0, C18sHsN O5  2HO  HO,C,14H503+ C4H5NO4.
SECTION V.
Kreatinine (C8H1,N302).
30 a. This substance is contained in healthy human
urine, in the proportion of about 0-4 in 1000 parts, and
in larger quantity in cow's urine, and, although its physiological and pathological relations have not yet been
fully investigated, it must be regarded as a very important constituent of the excretion.
In order to extract the kreatinine, a pint of urine is
neutralized with milk of lime, and chloride of calcium
is added as long as it causes a fresh precipitate. The
earthy phosphates are then separated by filtration, and
the clear liquid evaporated on a water bath to a small
bulk, so that the salts begin to crystallize out on cooling
After it has been allowed to stand for some time, the
liquid is poured off into another vessel (leaving the deposit), mixed with about - th of a saturated solution of
chloride of zinc, well stirred with a glass rod, and set
aside for three or four days. A crystalline precipitate
will then be deposited, consisting of a compound of
kreatinine with chloride of zinc (CH7N302,OZnCl). This
is washed two or three times with small quantities of
cold water, and dissolved in boiling water. The solution
is boiled in a dish, and freshly prepared hydrated oxide
of lead* added in small portions, till a yellow precipitate
(oxychloride of lead) has separated, and the solution is
decidedly alkaline. The kreatinine is thus set free and
dissolved by the water, whilst the chloride of zinc is
decomposed by the hydrated oxide of lead, with production of hydrated oxide of zincand oxychloride of lead,
which are both insoluble in water. The filtered liquid
* Prepared by precipitating nitrate of lead with a slight excess of
potash, and rapidly washing, on a filter, so long as the washings are
strongly alkaline.




KREATININE.                   387
is boiled with a little animal charcoal, which removes
the coloring matter, as well as any oxide of lead which
may have dissolved, and after a second filtration is evaporated to dryness on the water-bath. On treating the
residue with hot alcohol, the kreatinine is dissolved, and
may be obtained in beautiful transparent prisms, by
allowing the alcohol to evaporate. The portion left undissolved by the alcohol generally contains kreatine
(C3H9N304), a feeble organic base, which is found in the
juice of flesh. It was formerly thought that the kreatine
was also a constituent of urine, but recent experiments
have shown it to be formed from the kreatinine, during
the evaporation of the urine, by the assimilation of the
elements of water:
Kreatinine.     Kreatine.
C8H7N302 + 211O = C8H9N304
Since this change takes place, even in the cold, in alkaline
solutions, the urine should be filtered as rapidly as possible after the addition of milk of lime, and a large excess
of the latter should be avoided.
IKreatinine forms brilliant prismatic crystals, which
dissolve in twelve parts of cold, and in a smaller proportion of hot water or of alcohol. The solution is alkaline
to test-papers, and, even though moderately dilute, yields
a characteristic crystalline precipitate with solution of
chloride of zinc, especially on stirring. It combines with
acids to form crystalline salts.
Quantitative determination of kreatinine in urine.-In
order to determine the quantity of kreatinine in urine,
the process given above requires some modification. The
following is the method adopted by Neubauer for the
estimation of kreatinine in the form of the double compound with chloride of zinc.
About 5000 grs. of urine are rendered slightly alkaline
with milk of lime, and chloride of calcium  is added as
long as any fresh precipitate is formed. The filtered
liquid is evaporated nearly to dryness on the water-bath,
and mixed, while still warm, with about an ounce of
strong alcohol (95 per cent.); the mixture is rinsed into
a beaker, set aside for four or five hours and filtered, the
4




38                HEALTHY  URINE.
residue upon the filter being washed with alcohol. The
filtrate and washings are evaporated to about one and a
half ounce, and mixed with a small quantity of a very
strong alcoholic solution of chloride of zinc. After being
briskly stirred, the mixture is set aside for three or four
days, when the crystalline compound of kreatinine with
chloride of zinc may be collected on a weighed filter,
washed with alcohol, and dried at 212~. From the weight
of the precipitate, that of the kreatinine may be found by
the proportion:
Ate. wt. of kreatinine    Ate. wt. of
and chloride of zinc.    kreatine.
-.______...j -- X _ _- -____ -- - J
181:   113::  weight of precipitate: x.
SECTION VI.
Vesical Mucus and.Epithelial Scales.
31. The small traces of mucus and epithelial debris,
which are always present in urine, and which do not
generally amount to more than from 0'1 to 0'3, in 1000
parts of the healthy secretion, are derived from  the internal surface of the bladder and urinary passages.  The
quantity is so small as to be scarcely visible in healthy
urine, until after standing a short time, it has subsided,
in the form of a thin cloud, to the bottom of the liquid.
It may be separated by passing
Fig. 5.         the urine through a filter, on
the sides of which it will be
deposited in the form of a shin-'i ~; ~    ing pelliele.
Q"~. ~:7/,,~~       32. *When examined under
I  ~    the microscope, mucus is found
to consist of minute granular
corpuscles (Fig. 5, a) floating
in the fluid, which are colorless, or nearly so, more or less
round, and frequently oval in
Mucus Corpuscles and Scales of Epi- shape, and usually accompathelium. Magnified 200 diameters. nied by epithelial scales.  The
mucous corpuscles dissolve when treated with strong nitric
and acetic acids, forming a solution from which, after




EXTRACTIVE MATTER.                   39
boiling, ferrocyanide of potassium throws down a white
precipitate.
33. When treated with dilute acetic acid (HO, C4H303),
these corpuscles become more transparent, lose their
granular appearance, and show in the interior one or
more distinct nuclei (662). The corpuscles are unaffected,
or nearly so, by the dilute mineral acids, but readily dissolve in a solution of potash. For the further characters
of mucus, see paragraphs 99, 153, 210, 247, 660, &c.
34. The epithelial scales found in the urine, associated
with mucus, and derived from the epithelial covering of
the organs through which the secretion has passed, are
usually more or less torn and broken (Fig 5), but are
occasionally met with uninjured, when they have the
appearance shown at b in the figure.
SECTION VII.
Extractive Matter.
35. The term extractive matter is usually applied to
those organic constituents of animal fluids, the nature of
which cannot be exactly defined, and its use therefore
becomes more restricted in proportion as analysis advances. Thus, within the last few years, the analyses of
urine have disclosed, among the extractive matters,
minute proportions of two substances, which are also
found in the juice of muscular flesh, viz., kreatine
(CHN3O4), and kreatinine (C8117N302), as well as a little
grape-sugar.* The peculiar yellow coloring matter of
the urine is also included under the head of extractive
matters, together with minute quantities of fatty acids.
36. In stating the results of an analysis of urine, it is
usual to distinguish between the alcoholic extractive matters, which are soluble in alcohol, and the watery extractive, which will dissolve only in water. The former averages about twelve parts in 1000 of normal urine, whilst
the watery extract amounts to only two or three parts.
D* r. Bence Jones (Quart. Jour. Chem. Soc., April, 1861) lhas obtained as much as two grains of grape-sugar from forty ounces of
healthy urine.




40               HEALTHY URINE.
The real nature of these matters is still very imperfectly
understood; and until we shall have obtained further
insight into them and their connection with the animal
functions, the student may consider them as so much undefined matter excreted from the body; without waiting
to inquire whether lactic acid and other compounds, the
presence of which may at present be considered as uncertain, are or are not contained in it.
Co oring matters obtainedfrom urine.-The yellow coloring matter of urine is characterized by the purple color
which it gives when heated with concentrated hydrocloric acid. A peculiar red coloring matter containing iron,
and very similar in its character to the coloring matter of
the blood, has been extracted from urine* by the following process: The urine was evaporated to a syrup, and
treated with alcohol; the alcoholic solution boiled, and
gradually mixed with milk of lime, until it was decolorized. The precipitate containing the coloring matter in
combination with lime was filtered off and washed successively with water and ether; it was then dried and
treated with a mixture of hydrochloric acid and alcohol,
by which the coloring matter was dissolved. By shaking
the alcoholic solution with an equal volume of ether during
several days, the coloring matter was obtained in ethereal
solution, and after washing the latter with water, and
evaporating, was left as a dark red mass, consisting of the
urohematin accompanied by a resinous substance.
Several observers have recorded the occasional presence
of a blue coloring matter in urine, as well as the existence,
in other cases, of some substance which gave rise to the
separation of an insoluble blue matter, when the urine
was mixed with sulphuric or hydrochloric acid and allowed to stand. Dr. Hassall showed that this substance
corresponded, in its properties, to ordinary indigo-blue,
and the more recent experiments of Schunck have demonstrated the existence in most specimens of healthy urine
of a substance possibly identical with the indican existing
in woad, which is resolved, by the action of strong acids,
* Harley, Journ. Pr. Chem., xliv. 264.




AMMONIACAL SALTS.                      41
into sugar and indigo-blue (C,,HlNO02). Indigo was obtained from most of the samples of healthy urine by the
following process: sixteen ounces of urine are mixed with
tribasic acetate of lead in excess, and filtered. The filtered
liquid is mixed with an excess of ammonia, the precipitate collected and decomposed with cold dilute sulphuric
acid. The solution is again filtered and set aside, when it
deposits a blue precipitate.  If this be filtered off; washed
with a little caustic soda, and then with boiling alcohol,
the latter dissolves a purple-red coloring matter, which
resembles the so-called purpurine, and leaves indigo-blue
undissolved, which may be recognized by its evolving
violet vapors, condensable to coppery scales, on heating
and by its dissolving, with a blue color, in concentrated
sulphuric acid.t
The odor of urine is caused by minute quantities of
certain volatile acids, among which phenylic or carbolic
acid (C,121O02) only is well known.
SECTION VIII.
Ammoniacal Salts.
37. In perfectly fresh urine these are present in very
small quantity.  The urate of ammonia which has been
already noticed (19), appears to be one form in which the
uric acid present in the urine is held in solution, since
the free acid requires for its solution a larger proportion
of water than the secretion usually contains.
38. The presence of ammonia in urine is best shown
by adding a little caustic baryta (BaO,HIO)T to the resi* Samples of urine in which no sugar could be detected by the
copper-test, when heated with sulphuric or hydrochloric acid, deposited
brown flakes, and the filtered liquid gave decided indications of sugar.
The brown precipitate had the same composition as anthranilic acid
(C,4H7N04), which is a product of the decomposition of indigo-blue;
it dissolves in boiling alcohol, with a fine purple color.
t Heller calls the yellow coloring matter of the urine uroxacnthin,
terming the red substance derived from it urrhodine, and the blue
uroglaucine.
t Baryta is here to be used in preference to potash, since the latter
would cause the evolution of ammonia by its action upon the urea,
which, in presence of the alkalies, is converted into carbonate of amniollia (11).
4*




42               HEALTHY URINE,
due left after evaporating the liquid nearly to dryness at
a gentle heat, when the odor of ammonia will be perceptible, and a rod moistened with dilute hydrochloric acid,
held over it, will give rise to the characteristic white
fumes of hydrochlorate of ammonia. The proportion of
ammonia contained in healthy urine appears to be very
small: in some forms of disease, however, especially in
certain kinds of fever, the quantity is found to increase
considerably. Neubauer found, in the case of one person
in health, about thirteen grains of ammonia in the excretion of twenty-four hours. In another case, about eight
grains.
SECTION IX.
Fixed Alkaline Salts.
39. In order to obtain the fixed salts present in the
urine, about eight ounces should be evaporated to dryness
in a porcelain dish, in which
Fig. 6.          the residue  is afterwards
heated as long as any fumes
2oOPJi   9Ka2          escape; the resulting carbo0~~O~-obg Ci7      naceous mass is powdered:o?- "~ ~.~A/Oo~'o S-and  introduced  in  small
~X             $ 7,i~u~" 4~s~ portions into a porcelain
ej/(~' ~   ~:~n Adz %~%;" Ocrucible heated to a very
J"'~ 1A    16       low redness.*  In this way
4,>t ( —b.'     the carbon will be gradually burnt off; and a gray or
~ XOCX4  o`""  ~   white ash left, consisting of
7('y   oo          a mixture of the alkaline
Evaporated Residue of Healthy Urine.  and earthy salts; the former
may then be separated from
the latter by dissolving in water, in which the earthy salts
are insoluble (43). The composition of this ash, however,
will not exactly represent that of the inorganic portions of
the urine, on account of the chemical changes induced
among its constituents during incineration.
* At a higher temperature, partial fusion might take place, rendering
complete incineration impossible;'some of the alkaline chlorides might
also be lost.




FIXED ALKALINE SALTS.               43
40. The alkaline salts, which in the healthy secretion
usually amount to from ten to twelve parts in 1000, consist of the sulphates of potash and soda (KO,SO3) and
(NaO,SO03), chloride of sodium (NaCl), chloride of potassium (KCI), and phosphate of soda (2 NaO,tHO, P05 + 24Aq).
The crystalline residue left after slowly evaporating a few
drops on a piece of glass, usually has the appearance represented in Fig. 6. The crosslets (a) consist of chloride of
sodium, and the more plumose crystals (b) are probably
phosphate of soda.
41. The presence of these several salts may be shown
by adding to the aqueous solution of the ash the following tests:(a) Nitrate of Silver (AgO,NO5) throws down a whitish
precipitate, cotrsisting of a mixture of chloride (AgCl)
and phosphate (3AgO,PO) of silver.  These may be
separated from each other by warming the precipitate
with a little nitric acid, when the phosphate will dissolve,
leaving the insoluble CHLORIDE, which may then be tested
with ammonia, in which it is readily soluble.
(b) The acid solution separated from the chloride (a)
must now be cautiously neutralized with ammonia, which
will throw down a pale yellow precipitate of PHOSPHATE
(3AgO,PO,), which may be again dissolved by adding a
slight excess of nitric acid.
(c) Chlorideof barium (BaCl), or nitrate of baryta (BaO,
NO5), throws down a white precipitate of sulphate of
baryta (BaO,SO3), mixed with phosphate of baryta (2BaO,
HtO,PO,); which latter may be separated by dilute hydrochloric acid, which leaves the sulphate undissolved,
proving the presence of SULPHURIC ACID. If the acid
solution of the phosphate be neutralized with ammonia,
the phosphate of baryta is again precipitated.
In order conclusively to prove the presence of phosphoric acid, another portion of the aqueous solution of
the ash should be acidified slightly with acetic acid, and
a drop of perchloride of iron (Fe2Cl3) added, which will
cause a yellowish-white precipitate of perphosphate of
iron (Fe2O3,PO5).
(d) The absence of all bases except the alkalies, may
be proved by testing the solution with hydrosulphate of




44               HEALTHY URINE.
ammonia (NHAS,IIS), and carbonate of soda (NaO, C02),
neither of which will be found to cause any precipitate.
(e) POTASH may be shown to be present by adding to
a little of the strong solution about an equal quantity of
bichloride of platinum (PtCl2), which will cause a yellow
precipitate of the double chloride of platinum and potassium (KC1,PtCl2)' and another portion may be stirred on
a slip of glass with solution of tartaric acid, which will
throw down. a white crystalline precipitate of the bitartrate (KO,HO,CHO401,o)
(f) SODA may be identified by dipping a clean platinum wire into the solution, and heating it in the blowpipe flame, which will be tinged golden yellow.
42. It is difficult to say in what exact state of combination these several bases and acids exist in the urine:
but it is most probable that each base is divided among
the several acids, and that a portion of each of the acids
is combined with some of each of the fixed bases, and
also of the ammonia (37,40).
SECTION X.
Earthy Salts.
43. The earthy salts, which form the insoluble portion
of the ash, and which usually amount in healthy urine to
about one part in 1000, consist of the phosphates of lime
and magnesia, together with a small trace of alumina and
silica. These earthy phosphates,
Fig. 7.      which are insoluble in water, appear to be.iretained in solution in
the urine by the small excess of acid:c.:''-":.-...   (probably phosphoric) usually pre":.;~::  sent in the healthy secretion, and
may be immediately precipitated;,'.from  it by supersaturating with
ammonia.  The precipitate thus
formed consists of a mixture of
Mixed Phosphates.   PHOSPHATE OF LIME (3CaO,PO),
and the DOUBLE PHOSPHATE OF AMMIONIA and MAGNESIA (2MgO,N1H4O,PO0+12Aq), which
is also called TRIPLE PHOSPHATE. If this precipitate be




EARTHY SALTS.                     45
examined under the microscope, it will generally be
found to consist of minute crystals of the triple phosphate, mixed with amorphous particles of phosphate of
lime (Fig. 7). Collect the precipitate upon a filter, wash
it several times with water, and drop a little nitrate of
silver upon it.  The formation of the bright yellow
phosphate of silver (3AgO,PO5), will indicate the presence of phosphoric acid.
44. The crystalline form of the triple phosphate, as
well as its chemical composition, depends upon the quantity of ammonia present in the liquid during its formation.  When the urine is cautiously neutralized with the
alkali, the crystals are prismatic (Fig. 8), and in a few
rare cases, penniform* (Fig. 9), and appear to consist of
Fig. 8.                      Fig. 9.
Prismatic Crystals of Triple Phosphate.  Penniform Crystals of Triple
Phosphate.
(MgO,NH4,0,    0,PO); while, if a decided excess of ammonia be added, the crystals are star-like and foliaceous
as shown in Fig. 10, and then consist of (2MgO,NHO,
P05+12Aq).  When the urine gradually becomes alkaline, owing to the spontaneous formation of amnmonia
from the urea (11), the triple phosphate is precipitated
in the prismatic form, crystals of which are always to be
detected in stale urine.
45. Both varieties of triple phosphate will be found
to develop beautiful colors when examined with polarized
light.
* According to Dr. Hassall, these consist of phosphate of lime.




46                HEALTHY  URINE.
Fig. 10.
Stellate Crystals of Triple Phosphate.
46. The presence of phosphoric acid, in combination
with lime and magnesia, together with a trace of silica,
in the insoluble portion of the ash, may be shown by
digesting a considerable quantity of the latter in dilute
hydrochloric acid, and filtering the solution from the insoluble residue. This insoluble portion,* the amount of
which is usually very small, may then be washed, and
tested for SILICA, by fusion before the blowpipe with
carbonate of soda, with which it will form, when pure,
a clear colorless bead (Prac. Chem. 138).
47. The acid solution of the phosphates, filtered from
the silica, may then be divided into two portions, and
tested as follows:(a) Add ammonia in slight excess, redissolve the precipitate by adding acetic acid, and add a few drops of
perchloride of iron; the yellowish-white precipitate (Fe9
03,PO) indicates the PHOSPHORIC ACID.
(b) To the same portion add about twice its volume of
water, and boil for a few seconds to precipitate the whole
of the phosphate of iron; filter, and add oxalate of anmmonia, which will precipitate the LIME as oxalate (CaO,
C203).
(c) The mixture (b) is boiled, and filtered from the
oxalate of lime; after which the clear solution is well
stirred with a decided excess of ammonia, which will in
a short time cause a disposition of the crystalline double
phosphate of ammonia and MAGNESIA, thus proving the
presence of the latter base.
* This residue generally contains carbon, which should be burnt
off upon platinum foil.




EARTHY SALTS.                  47
48. The same experiments (a, b, & c) may also be made
upon the phosphates which are thrown down by the addition of ammonia to fresh urine.
49. The earthy phosphates may also be distinguished
by the following peculiarities, which may be readily seen
either with or without the assistance of the microscope:(a) When present in excess they may frequently be
precipitated from the urine in an amorphous form by
boiling, thus behaving like albumen (139). The phosphatic deposit may be readily distinguished from the
latter, by being soluble in a few drops of nitric acid, and
in not being reprecipitated by any excess of that reagent
(140).
(b) The earthy phosphates are readily soluble, without
effervescence, in dilute acids, such as the hydrochloric,
nitric, and acetic; and are reprecipitated by neutralizing
the acid solution with ammonia; that of lime being amorphous, and the triple phosphate, in crystalline form,
either prismatic or stellate (43).
(c) They are insoluble in a solution of potash. The
triple phosphate, when warmed with an excess of the
alkali, gives off ammoniacal fumes, which may be detected
by the smell, and by the white cloud formed when a rod
moistened with dilute hydrochloric acid is held at the
mouth of the tube.  2MgO,N,40,PO, +2(KO,HO)=
2(MgO,HO) + 31N  + 2KO,O, PO5.
(d) When heated before the blowpipe, phosphate of
lime experiences little or no change, unless the heat be
very intense, and continued for a long time, when it
sometimes partially fuses. The triple phosphate, when
heated, gives off ammonia and water; and the residual
phosphate of magnesia (2MgO,PO) fuses considerably
more readily than the phosphate of lime. When the
two phosphates are mixed in about equal proportion,
they resemble in composition the fusible calculus, and
fuse with extreme facility before the blowpipe (392).




48        QUANTITATIVE ANALYSIS OF
CHAPTER TI.
QUANTITATIVE ANALYSIS OF HTEALTHY URINE.
50. COUNTERPOISE or weigh two Berlin porcelain evaporating basins, which for the sake of distinction, may
be marked A and B, each capable of holding about four
ounces of water; and retain the counterpoises, marking
them in order to avoid confusion. Then weigh into each
of the basins, 1000 grains of urine, and allow them to
evaporate first on the water-bath, and afterwards in a hotwater oven, or chloride of calcium bath,* until they cease
to lose weight when weighed at intervals of an hour or
two. While the evaporation is going on, the experiments
described in paragraphs 59, 66, &c., may be proceeded
with. The specific gravity also may be determined (278),
and the action of the urine on test-paper ascertained (277).
Then accurately weigh them, and if the weights of both
residues agree with each other, the loss experienced during evaporation will represent the quantity of WATER contained in the urine. If the weights do not agree, it is
probable that desiccation of at least one of the portions
has been incomplete; in which case it is better to continue the heat a short time longer, until the results agree
more closely.
51. The residue A may be first examined, retaining B
for subsequent examination (62).
52. Warm the residue A with half an ounce or an
ounce of alcohol of specific gravity about'833, stirring
the mixture occasionally with a glass rod. Pour off the
solution into another basin, and again warm the residue
with a little more alcohol, fresh portions of which must
be added until it ceases to dissolve anything more.
* Pract. Chem., pp. 201, 212o




HEALTHY URINE.                  49
Whether this is the case, may be known by evaporating
a drop of the clear liquid on platinum foil or a slip of
glass, when, if anything has been dissolved, it will be left
behind as a residue. The aleclholic solution, which will
contain the whole of the urea, contaminated with extractive matter and other impurities, is now to be evaporated
to dryness on a water-bath, retaining the residue which
proved insoluble in the alcohol for subsequent examination (57).
53. The residue, containing the urea, left after evaporating the alcoholic solution (52), is now to be dissolved in
as small a quantity as possible of lukewarm water, and
mixed with pounded oxalic acid (HO,C203+ 2Aq), which
may be added as long as the liquid, heated to about 1900
or 200~, continues to dissolve it (14). The urea is thus
converted into the oxalate (C2H4N2O2,HO, C203), which,
as the solution cools, crystallizes out, mixed with some
of the excess of oxalic acid employed, together with extractive matters and other impurities, which give the
crystals a more or less intense brown color. The crystals
are to be washed in the basin with a very small quantity
of cold distilled water, which may be poured off, and
fresh water added to the crystals as long as it continues
to become decidedly colored; by which means most of
the soluble salts and other foreign matters are removed.
54. The washings are now to be concentrated to a small
bulk by evaporation on a water-bath, and left to cool,
when a fresh crop of crystals will gradually separate.
Care must be taken that an excess of oxalic acid is present in the liquid separated from the crystals, which may
be known by its reddening litmus paper; if this is found
on trial not to be the case, a little more of the pounded
oxalic acid must be added to the solution, as otherwise,
some of the urea, which, when uncombined, is very
soluble in water, might escape separation.
55. When the whole of the oxalate of urea has been
separated by successive crystallization from the liquid,
it must be gently pressed between the folds of filtering
paper, and dissolved in warm water; after which the
solution is to be digested for a few hours, at a temperature of about 1000, with pounded carbonate of lime,




50         QUANTITATIVE ANALYSIS OF
stirring the mixture from time to time with a glass rod,
as long as any effervescence is produced. The oxalate is
thus decomposed in the following manner:Oxalate of urea.      Oxalate of lime.
CH42,02,O, C203 + CaO,CO,2= CaO,C20,+ C02+ HO
Urea.
+ C1r-4N2 0256. The urea, which being soluble remains in solution,
is to be separated by filtration from the insoluble oxalate
and carbonate of lime, and carefully evaporated to dryness either on a water-bath or in vacuo over sulphuric
acid. Its weight will then represent the proportion of
UREA in 1000 grains of the specimen of urine under
examination.*
57. The portion of the residue which proved insoluble
in the alcohol (52), containing the uric acid, vesical mucus, the extractive matter soluble in water, but insoluble
in alcohol, the earthy salts, and most of the other saline
matter, is now to be well stirred with successive small
portions of warm water, which leaves undissolved the
uric acid, mucus, and earthy salts. The insoluble matter
is to be collected upon a filter, which has previously been
dried and weighed, and then carefully dried on a waterbath, or in a hot-water oven, and weighed. The weight
having been noted, the dry residue is to be ignited together with the filter in a crucible, until the incombustible
ash becomes white, or very nearly so; when the crucible
with its contents is to be again weighed. The difference
between this weight and that of the dry residue previous
to ignition, gives the amount of combustible matter, consisting of URIC ACID and VESICAL MuCUS; while that of
the ash represents the EARTHY PHOSPHATES AND SILICIA.
58. The portion of urine A will now have given us the
weight of-1. The water; 2. Urea; 3. Uric acid and
vesical mucus; and 4. Earthy phosphates and silica.
59. For the purpose of ascertaining the respective
weights of the uric acid and vesical mucus, 2000 grains
* The exact determination of the amount of urea in urine must be
effected by an indirect method, which will be subsequently described.




HEALTHY URINE.                    51
of the fresh urine may be concentrated by evaporation
to about half its bulk, and mixed with twenty or thirty
drops of hydrochloric acid.* In the course of twentyfour hours, the whole of the uric acid will have been set
free by the hydrochloric acid, and being insoluble (22),
will be deposited in the form of minute crystals on the
sides and bottom of the glass. These are to be collected
on a weighed filter, and, after being washed with a little
alcohol, dried in a hot-water oven or on a water-bath.
The weight of this acid, divided by two (since it is derived
from 2000 grains of urine), will represent the URIC ACID
contained in 1000 grains of the secretion; and having
already determined the quantity of uric acid and VESICAL
MUCUS together (57), the weight of the latter is known
by deducting fiom the combined weights that of the uric
acid.
60. The proportion of uric acid and mucus may also be
determined by evaporating to dryness 1000 grains of the
urine previously filtered from the mucus, and washing
the residue first with dilute hydrochloric acid (containing
one part of acid to eight or ten of water), and afterwards
with a little alcohol. We thus dissolve out everything
but the uric acid, which, after being washed with cold
water, may be dried and weighed.
61. If it is required to determine the respective proportions of earthy phosphates and silica in the residue of
earthy salts (57) —which, however, is seldom necessary,
since the quantity of silica is always very smnall-it may
be done in the following manner: Moisten the residue
with hydrochloric acid, and evaporate to dryness; then
digest it with the aid of a gentle heat, in dilute hydrochloric acid, which will dissolve out the phosphates, leaving the sILICa perfectly insoluble. The weight of the
latter is then ascertained, and deducted from the gross
weight of the earthy salts (57), when the differences will
represent that of the EARTHY PHOSPHATE; or the phosphates may be precipitated from the hydrochloric acid
* In general, the uric acid may be determined in the urine without
previous concentration, if it be acidulated and set aside for twentyfour hours.




52                 HEALTHY  URINE.
solution by supersaturating it with ammonia, filtered,
ignited, and weighed.
62. We have now to operate upon the residue left after
the evaporation of the second portion of urine marked B
(50), for the purpose of determining the weight of-i.
The animal extractive and ammoniacal salts; and 2. The
fixed alkaline salts.
63. The dry residue, after being accurately weighed, is
to be incinerated (39) in a platinum or porcelain crucible,
until the whole of the blackness (carbon) has disappeared,
after which the weight of the ash is to be noted.* The
loss experienced during ignition being due to the combustion of the organic matters and the volatilization of
the ammoniacal salts; and as we have already ascertained
the weight of the urea, uric acid, and vesical mucus, we
have only to deduct from the whole amount of loss the
combined weights of those three substances, in order to
determine the quantity of the ANIMAL EXTRACTIVE AND
AMMONIACAL SALTS.
64. The ash obtained by ignition contains the whole of
the inorganic matter, or, in other words, the fixed alkaline
and earthy salts contained in the urine. By deducting
from this the weight of the earthy salts already determined (57), we obtain the proportion of FIXED ALKALINE
SALTS.
65. We shall thus have determined the proportion of
the
Water,
Urea,
Uric acid,
Vesical mucus,
Animal extrac.tive ancl ammoniacal salts,
Fixed alkaline salts,
Earthy phosphates,
Silica,
which, when added together, ought to make up a fraction
less than 1000 grains, some slight loss being unavoidable
during the course of the analysis.
* If al exact determination of the amount of ash be required, the
dry residue must be carbonized by a low heatl until no more fumes
are evolved, the soluble salts thoroughly extracted from it by boiling
water, and their weight determined by evaporating the filtered-liquid.
The coal containing the insoluble salts is then dried and burnt, at a
higher temperature, to a white ash.




INORGANIC SALTS.                 53
Q an titative determination of Ammonia.
65a. Place about an ounce of filtered urine in a shallow
flat evaporating dish, upon which is supported, by means
of a triangle made of bent glass rod, a smaller flat dish
containing half an ounce of dilute sulphuric acid, which
is known to be exactly neutralized by a certain amount
of a standard solution of soda. Add to the urine about
half its volume of milk of lime, cover the whole with a
bell glass, and allow it to stand for forty-eight hours. The
ammonia which is set free by the lime will be absorbed
by the sulphuric acid, and it only remains to ascertain
how much of the latter has been neutralized by the ammonia, which is easily done by means of the solution of
soda above referred to. Every forty grains of sulphuric
acid (SO3) neutralized, will represent seventeen grains of
ammonia (NH3).* Dark-colored urine, which easily putrefies, must be precipitated with a mixture of acetate and
tribasic acetate of lead, and filtered before determining
the ammonia.
Quantitative determination of the Inorganic Salts.
66. For the sake of practice in analysis, it will be well
for the student to determine the proportions of the seteral
bases and acids contained in the ash obtained in (39) and
(63), but for purposes of diagnosis, it is more convenient
to estimate the alkaline and earthy phosphates, the sulphuric acid, and the chlorine in the original urine, and
this is the more necessary because the composition of the
ash of any given sample of urine is liable to variation,
according to the temperature at which the incineration
was conducted.
67. For the quantitative analysis of the ash, about sixty
grains will be required, which would be furnished by
about 5000 grains (ten fluidounces) of urine treated according to the directions given in (39); the ash should
be thoroughly mixed together in a dry mortar whilst still
warm, and transferred to a stoppered bottle.
68. Determination of time, magnesia, and phosphoric arid.
* This process was devised by Neubauer.
-.5




54        QUANTITATIVE DETERMINATION
-Heat twenty grains of the ash with dilute hydrochloric
acid for a few minutes, and filter the solution from  the
undissolved residue (carbon and silica,) taking care to
wash the latter as long as the washings are acid.  Mix
the filtered solution with ammonia in excess, stir it well,
and allow it to stand for some time (if possible for twelve
hours). Collect the precipitate of phosphate of lime
(3CaO,PO5), and phosphate of magnesia and ammonia
(2MgO,N140,P05) upon a filter, wash it with ammoniacal water as long as the washings leave any considerable
residue, when evaporate upon a slip of glass and save
the filtrate and washings for further examination (72).
69. Determination of lime.-Dissolve the precipitate off
the filter with a little warm acetic acid, taking care to
wash the filter, and mix the solution with oxalate of
ammonia. Allow it to stand for some time, that the
oxalate of lime (CaO,C203) may separate, collect it upon
a filter, wash it till the washings leave no residue on
evaporation, dry, and ignite, together with the filter, in a
weighed crucible, when the oxalate will be converted into
carbonate of lime (CaO,CO,).  Moisten the ignited precipitate with a little carbonate of ammonia, to convert
any caustic lime into carbonate, dry at a moderate heat,
and 4veigh. The amount of lime may then be calculated
by the proportionAte. wt. of carb.  Ate. wt. of  Wt. of carb. of lime   Wt. of lime in
lime.      lime.       obtained.    20 grs. of ash.
50          28::       a:    x
70. Determination of magnesia. —Th e filtrate and washings from the precipitate of oxalate of lime (69), are concentrated by evaporation, mixed with excess of ammonia,
well stirred, and set aside for twelve hours; the precipitate of phosphate of magnesia and ammonia is collected
upon a filter, washed with ammoniacal water, dried,
ignited and weighed. Since it is converted by ignition
into pyrophosphate of magnesia (2MgO,PO,), the amount
of magnesia will be calculated by the proportionAtc. wt. of    Ate. wt. of  Wt. 2MgO,PO,  Wt. of magnesia in
2MgO,PO,.    2MgO.    obtained.    20 grs. of ash.
111-4:   40'4::        a:     x




OF THE INORGANIC  SALTS.                  55
By deducting the weight of the magnesia from the total
weight of the precipitate, we obtain the amount of phosphoric acid which was in combination with magnesia in
the twenty grains of ash employed.
71. Determnination of phosphoric acid.-In order to determine the phosphoric acid which was in combination
with the lime, the filtrate and washings from  the phosphate of magnesia and ammonia (70) may be concentrated by evaporation, and the phosphoric acid precipitated by adding a mixture of sulphate of magnesia, chloride of ammonium, and ammonia, and proceeding with
the precipitate as in the last experiment, the amount of
phosphoric acid being calculated by the proportionAtc. wt. of   Ate. wt. of  Wt. of 2MgO,PO0   Wt. of phosphoric acid
2MgO,POS.    PO,       obtained.     in 20 grs. of ash.
1114:   71::        a:        x
72. To ascertain the amount of the phosphoric acid
which was in combination with the alkalies, the filtrate
and washings from the first precipitate produced by
ammonia (68) are evaporated to a small bulk, and the
phosphoric acid determined precisely'as in the last case.
73. D)etermination of the chlor'ine.-Dissolve  twenty
grains of the ash in a little dilute nitric acid with the
aid of heat, filter, wash the filter till the washings are no
longer acid, and mix the filtered solution with nitrate of
silver as long as it causes a fresh precipitate; stir the
solution briskly to favor the separation of the chloride
of silver, collect the precipitate upon a small filter, wash
it till the washings are no longer rendered turbid by
hydrochloric acid, dry it, detach every particle from the
filter, and fuse it carefully in a weighed porcelain crucible; burn the filter, allowing the ash to drop into the
crucible, again ignite till all the carbon has burnt off,
and weigh.*  From  the weight of the chloride of silver
that of the chlorine is calculated by the proportion* If the precipitate be too small to be detached fiom the filter, the
latter must be burnt with it, and the ash afterwards moistened with
a few drops of nitric and hydrochloric acid, to convert the reduced
silver into chloride; it is then again ignited and weighed.




56        QUANTITATIVE DETERMINATION
Ate. wt. of chloride  Ate. wt. of   Wt. of AgC1   Wt. of chlorine in
of silver.  chlorine.    obtained.   20 grs. of ash.
143-5:   35 5::    a:       x
74. Determination of sulphuric acid and the alkalies.Dissolve twenty grains of the ash in hydrochloric acid,
filter the solution (68) and precipitate with excess of
chloride of barium; collect the sulphate of baryta (BaO,
SO3) upon a (Swedish) filter, wash it with hot water till
the washings leave no considerable residue when evaporated, and save the filtrate and washings for further
examination (75). Dry the sulphate of baryta, empty
as much of it as possible into a weighed crucible, burn
the filter so that the ash may fall into the crucible, ignite
till all the carbon has burnt off, and weigh. The amount
of sulphuric acid is calculated by the proportionAte. wt. of   Ate. wt. of   Wt. of BaO,SO3   Wt. of sulphuric acid
BaO,SO3.    SO3.        obtained.     in 20 grs. of ash.
116-5;    40;:     a:        x
75. In the liquid filtered from the sulphate of baryta,
the potash and soda have now to be determined. For
this purpose, ammonia in excess, and carbonate of ammonia must be added, and the solution gently heated.  The
excess of baryta, together with the lime, magnesia, and
phosphoric acid, are thus precipitated, and must be filtered off; and washed till the washings leave no considerable residue on evaporation. The filtrate and washings
are then evaporated to a small bulk, introduced into a
weighed porcelain or platinum dish, carefully evaporated
to dryness and heated to dull redness, as long as any
fumes (of chloride of ammonium) escape.
76. The residue after ignition, consisting merely of
the chlorides of potassium and of sodium, is now to be
weighed. It is then dissolved in a small quantity of
water, mixed with a solution of bichloride of platinum,
and the mixture is evaporated to dryness on a water-bath.
The residue is treated with successive small portions of
alcohol, which will dissolve out the excess of the bichloride of platinum, together with the chloride of sodium;
leaving undissolved the double chloride of platinum and
potassium  (KCl,PtCl2).  The latter is to be dried in a




OF THE  INORGANIC  SALTS.                   57
weighed filter, at a temperature of 212~, and weighed.
From the weight of the double chloride thus obtained,
we may then calculate that of the POTASH equivalent to
it, as follows:Atc. wt. of the double                       Wt. of potash
chloride of platinum   Ate. wt. of  Wt. of the double  in 20 grs. of
and potassium.    potash.   chloride obtained.    the ash.
- — 4-4' - — J ~ —-- --—'~
244-1          47             a             x
77. From the weight of potash thus obtained, we are
enabled to ascertain how much of the mixed chlorides
(76) was chlorite of potassium; and the difference between the latter and the gross weight will of course represent the quantity of chloride of sodium. The weight of
chloride of potassium equivalent to the potash is for this
purpose calculated as follows: —
Ate. wt. of   Ate. wt. of chlo-   Wt. of pot-  Wt. of chloride of potassium conpotash.  ride of potassium. ash obtained.  tained in the mixed chlorides.
47          74-5::                       x: 
78. The weight of chloride of potassium thus calculated
is then deducted from the weight of the mixed chlorides
(76), and the difference will represent the weight of chloride of sodium; thus:Weight of mixed chlorides
Deduct weight of chloride of potassium.
WVeight of chloride of sodium..     
79. The whole of the soda, however, does not exist in
the urine as chloride of sodium, a portion of it being in
combination with phosphoric, and, perhaps, also with
some of the other acids present.  We have, therefore, to
calculate from the quantity of chlorine obtained in a former experiment (73) how much of the chloride of sodium
obtained in paragraph 78 existed as such in the urine.
This is done as follows:Ate. wt. of  Ate. wt. of chlo-   Wt. of chlorine in  Wt. of chloride of sodium.
chlorine.  ride of sodium.    20 grains of ash.  in 20 grains of ash.. —_r__J_.  v-__ ___t  -   "J %-_- _v- 
355:    58'5::        a                   x
80. The quantity of CHLORIDE OF SODIUM thus calculated
is deducted from the whole weight of chloride of sodium
previously obtained (78), and the difference will represent
the amount of chloride of sodium equivalent to the SODA,




58        QUANTITATIVE DETERMINATION
which in the urine was combined with phosphoric or
other acids; thus:Difference between
Ate. wt. of chlo-  Ate. wt.  the two amounts of Soda existing as such
ride of sodium.   of soda.  chloride of sodium. in 20 grs. of the ash.
585:  31::      a               x
81. All the quantities obtained in the foregoing experiments (68 to 80) represent the amounts of the several
saline ingredients contained in twenty grains of the ash;
as, however, the organic ingredients were estimated as
contained in 1000 grains of urine (65), the proportion of
the inorganic constituents should also be reduced to the
same scale. This may be done in the case of each constituent by the following calculation:r Quantity of in-    Wt. of each con-    ( Wt. of that
l organic mat- a     stituent obtained   ] constituent
20: (  ter in 1000 i::   from 20 grains of:  contained
grs. of urie.     the ash.            I in 1000 grs.
L            J                     J    [ of urine.
82. Determination of the alkaline and earthy phosphates,
the sulphuric acid, and the chlorine in the original urine.Although it would be very difficult to determine these
constituents in the original urine with perfect exactness,
it may be effected with sufficient accuracy for the purpose
of diagnosis, since the results of the analysis of each specimen of urine are affected by the same sources of error,
and may be compared with safety.
To ascertain the amount of earthy phosphates, 1000
grains of the urine may be mixed with excess of ammonia, and set aside for some hours. The precipitate is then
filtered off and washed, as in (68), dried, ignited, and
weighed.
The phosphoric acid contained in the solution filtered
from this precipitate will, of course, be the measure of
the alkaline phosphates present. In order to determine
its amount, the filtrate and washings are precipitated with
a mixture of sulphate of magnesia, chloride of ammonium,
and ammonia, set aside for twelve hours, and further
treated, as in (71).
Volumetric determination of phosphoric acid in urine. —
The phosphoric acid in urine may be determined very




OF THIE INORGANIC SALTS.               59
easily, and, after a little practice, with considerable exactness, by ascertaining the amount of iron required to precipitate it as phosphate of sesquioxide of iron (Fe2O3PO,)
from the urine, acidified by acetic acid.
A solution of sesquichloride of iron of known strength
is prepared by dissolving twenty-eight grains of clean
thin iron wire in half an ounce of hydrochloric acid, with
the aid of heat, and gradually adding one drachm of nitric
acid; the solution is evaporated very nearly to dryness
at a gentle heat, and the residue dissolved in water. If
the solution is not clear, it is rendered so by adding a
very little hydrochloric acid, and it is then diluted to
2000 grains.  100 grains of this solution correspond to
1'775 grains of phosphoric acid.
In order to confirm this, 3-58 grains of pure crystallized phosphate of soda (2NaO,HO,PO0+24Aq) are dissolved in an ounce of water in a small beaker, the solution mixed with a little ammonia,* then with an excess
of acetic acid, and the solution of iron added from  a
burette until a trace of iron can be detected in the filtered
liquid by ferrocyanide of potassium.
The most convenient mode of filtering a little of the
fluid consists in employing a small tube about five inches
long and half an inch wide, open at both ends, which
should be turned over like the rim of a test-tube. Over
one of these ends a circular piece of filtering paper is
tightly bound by a platinum  wire, so that its edges may
overlap about two inches of the tube. The filter-paper
having been moistened, it is dipped about an inch below
the surface of the liquid containing the precipitate, when
a few drops of the clear liquid will enter the tube, and
may be poured into a test-tube containing a little dilute
solution of ferrocyanide of potassium.  As soon as it is
found that, on making this experiment, a slight blue
tinge is produced, it is known that a sufficient quantity
of the iron solution has been added.
The 3'58 grains of phosphate of soda should have
* This ammonia serves to neutralize the hydrochloric acid which
is set free in the reaction, and which would. otherwise dissolve the
phosphate of iron: 2NaOHO,PO5 + Fe2Cl- = Fe23,PO5 +- 2NaC1 +
HC1.




60    QUANTITATIVE DETERMINATION, ETC.
required forty grains of the iron-solution for complete
precipitation.
In order to determine the phosphoric acid in urine,
500 or 1000 grains (according to the state of concentration) may be mixed with ammonia in excess, then with
acetic acid in excess, and afterwards tested with the iron
solution in the manner just described. From the number
of grain measures of this solution required to complete
the precipitation, the amount of phosphoric acid is calculated by the proportion —
Grs. of iron  Phosphoric
solution.  acid.
100:  1'775::   Grs. of solution used:  x
If it be desired to determine the amount of phosphoric
acid existing in combination with lime and magnesia,
1000 grains of urine may be mixed with ammonia in
excess, allowed to stand for an hour or two, filtered from
the precipitated phosphates, the filtered liquid acidified
with acetic acid, and tested, as before, with the iron solution. The difference between the amount of phosphoric
acid thus obtained and the total quantity in 1000 grains,
inferred from the former determination, will represent
the phosphoric acid existing in the forms of earthy phosphates.
83. For the determination of the sulphuric acid, 500
grains of the urine are acidified with hydrochloric acid,
precipitated by chloride of barium and the precipitated
sulphate of baryta treated as in (74).
The chlorine may be determined by acidifying 500
grains of urine with nitric acid, precipitating with nitrate
of silver, and proceeding as in (73), avoiding as far as
possible, the reducing effect of light upon the silver-salt
in the presence of organic matter.
84. If it be required to compare the acidity of different
specimens of urine, it may be effected by adding to 1000
grains of the urine, from a graduated burette, a weak
solution of carbonate of soda, of known strength, until
it ceases to redden litmus paper. Of course the degrees
of acidity will vary as the quantities of carbonate of soda
employed.




COMPOSITION OF HEALTHY URINE.    61
CHAPTER III.
AVERAGE COMPOSITION OF HEALTHY URINE.
85. THE following analysis of healthy human urine
will serve to give some idea of its average composition.
Although in the amount of the several constituents they
will be seen to differ considerably from each other, it
will be found that these differences are not really quite
so great as they at first sight appear, being in a great
measure owing to variations in the relative proportions
of water and solid ingredients (1).
Analysis I. (Berzelius.)
Water...... 933'00
Urea.....                               30-10 1
Uric acid...                            100   [
Lactic acid, lactate of ammonia, and extractive matters.                17'14 
Mucus....  032 
Sulphate of potash.            3711   l 
Sulphate of soda.            3116 
Phosphate of soda...                2'94     1
Biphosphate of ammonia..  >65 1J,
Chloride of sodium..                 445 I 
Muriate of ammonia... 1'50 
Phosphates of lime and magnesia..    00 
Silica.                                   0'03 
1000.00J
Analysis II. (Simzon.)
Specific gravity 1012.
Water.. 956000
Urea....... 14578
Uric acid.                               0710
Extractive matters and ammoniacal salts   12-940      o
Chloride of sodium.                     7         ]280    1
Sulphate of potash...               3508I I 
Phosphate of soda                         2330 i
Phosphates of lime and magnesia..  0664     
Silica.a trace 
998 —J 000 
998'000'




62    COMPOSITION OF HEALTHY URINE.
Analysis IlI. (Dr. MJiller.)
Spec;fic?gravity 1020. -
Water... 9568000
Urea..    14-2300 ]
Uric acid.         0'3700 ]    29-812    ]
Alcohol extractive. 12 5270  -   Organic
Water extractive. m25204         matters.
Vesical mucus.   01650 J 
Chloride of sodium    7-2195 )-                       43'16
Phosphoric acid.  2'1189 [                  [ Solid matters.
Sulphuric acid.  17020
Lime...   02101          1 3349
Magnesia..   0'1198    Fixed salts. J
Potash...   19260
Soda...   0'0536 J
999-9623
Analysis IV. (iftarchand.)
Water...                  933'199
Urea...   32675 ]
Uric acid...                            1'065
Lactic acid...                          1521
Extractive matters.         11151
Mucus...    0283
Sulphate of potash.  3.587          66-8
Phosphate of soda.  3'056 t       Solid
Sulphate of soda...          3213        matters.
Biphosphate of ammonia...  1552
Chloride of sodium.  4218
Muriate of ammonia.           1652
Phosphates of lime and magnesia..   1'210 [
Lactates...                    1618 J
1000'000
Analysis V. (Lehlzann.)
Water.....                              937'682
Urea.                                     31450 ]
Uric acid.                                1021 
Lactic acid                                1.496
Water and alcohol extractives.    10'680
Lactates...                 1897   62318
Chlorides of sodium and amnmonia    3. 646 }    Solid.
Alkaline sulphates....   7314       matters.
Phosphate of soda..        3765
Phosphates of lime and magnesia.   1132
Mucus......   0112
1000'195 J




MORBID  URINE.                         63
Analysis VI. (Becquerel.)
Showing the comparative composition of 1lMale and Female Urine.
Mean composition   Ditto of four    General
of the urine of four healthy women.   mean.
healthy men.
Specific gravity. 1018'9      1015.12      1017'01
Water.           968-815     975-052      971'935
Solid constituents      31'185      24'948       28'066
Urea                  13-838      10-366       12'102
Uric acid...   0-391        0-406        0.398
Other organic matters   9'261      8'033        8'647
Fixed salts.   7'695        6'143        6'919
Consisting ofChlorine..                                0502
Sulphuric acid..                       0855
Phosphoric acid.  0'317
Potash..                                   1-300
Soda, lime, and magnesia...              3'944
CHAPTER IV.
MORBID URINE.
86. THE urine passed during a diseased state of the
system, is almost invariably more or less altered in its
composition, and frequently presents physical peculiarities, as of color, opacity, &c., which are at once apparent
on the most cursory examination. The variations which
are found to occur in the chemical composition of morbid
urine may be divided into two classes, viz:Ist. Those in which no abnormal ingredient is present;
but in which one or more of the normal constituents
is present either in greater or less proportion than
is found in healthy urine, or is altogether absent.
2d. Those in which one or more ingredients are present, which are not found in healthy secretion.




64                 MORBID  URINE.
I. Urine containing no abnormal ingredient, but in which an
excess or deficiency of one or more of its normal constituents
is present.
SECTION I.
Urine containing Urea in abnormal quantity.
87. Urine containing an excess of urea, is chiefly
characterized by its high specific gravity, in which respect
it resembles that secreted by diabetic patients (116). If
the urea be present in large excess, it deposits irregular
rhomboidal crystals of the nitrate (C21H4N202,IO,NO5),
when the urine, either in its natural state, or especially
when slightly concentrated, is mixed with an equal
quantity of nitric acid (181). The proportion of urea
present in the healthy urine passed during the twentyfour hours is usually about fourteen or fifteen parts in
1000 (10); while in disease it often amounts to thirty
parts, or even more.
SECTION IIL
Urine containing Uric (or Lithic) Acid in abnormal quantity.
88. When urine contains an access of uric acid, it has
usually rather a higher color than the healthy secretion,
either deep amber or reddish brown. Its specific gravity
is seldom much higher than 1020 or 1025, unless an
excess of urea is also present, which is not unfrequently
the case. It generally has a decided acid reaction to
test-paper; and if the uric acid is present in any considerable excess, it is partially deposited as the urine
cools, in the form of a crystalline sediment, usually of a
more or less decided red color, and frequently mixed
with urate of ammonia, mucus, and other matters.* The
crystalline forms in which uric acid is found in the urine,
are represented in paragraph 186. This deposition of
uric acid is greatly accelerated by the addition of a few
drops of nitric or hydrochloric acid to the urine (20).
89. The urine of infants and young children not unfrequently deposits lozenge-shaped crystals of nearly
*- Hippuric acid has been known to deposit together with uric acid.




IMORBID URINE.                   65
pure uric acid, containing only a trace of yellow coloring
matter. It rarely happens that uric acid is deposited in
the solid state previous to emission, being held in solution in the warm liquid, and gradually separating in the
form of a sediment, as the secretion cools (186).
90. The quantity of uric acid, which, in the healthy
scretion, is seldom more than from 0'3 to 1'0 in 1000
parts, varies in morbid urine from a scarcely perceptible
trace to upwards of two parts in 1000.
SECTION III.
Urine containing an excess of Urate (or Lithate) of Ammonia.
91. Urine containing an excess of urate of ammonia
varies very much in color and appearance, being sornetimes pale and of low specific gravity, but more frequently high colored, dense,
and turbid. It is most com-             Fig. 11.
monly slightly acid, but is also
met with neutral and even alka-     %~.. r. 
line. The urate of ammonia is:
gradually deposited as the urine
cools, in the form  of an amor-:.;
phous precipitate, which, with a
high magnifying power, appears;..;.
to consist of minute rounded..t
particles, occasionally adheirig 
together, and forming irregular
linear masses (Fig. 11); fre-        Urate of Ammonia.
quently mixed with microscopic
crystals of uric acid; and occasionally, when the secretion is neutral or at all alkaline, with the earthy phosphates (106).
92. Urate of ammonia has been met with, in a few
rare cases, in the form of globular masses of a larger size,
and pierced with spicular crystals, probably of uric acid
(Fig. 12). Like the other varieties of urate of ammonia
deposit, it is usually found mixed with crystals of uric
acid.
6*




66                  MORBID  URINE.
93. Urate of ammonia* constitutes one of the most
common of the urinary deposits.  The color of the sediment is found to vary considerably, being
Fig. 12.     met with all shades, from  pale fawn
color to reddish purple- or pink, the latter
t     purpurine, which is very frequently found
associated with the urates (104, 217).
Urate of soda, and traces of the urates of
lime and magnesia, are not unfrequently
Urate of Ammonia.t  found associated with urate of ammonia
deposits.
94. A deposit of urate of ammonia readily dissolves
when the urine containing it is gently warmed; and is
again precipitated as the liquid cools. If, however, as is
often the case, it contains also an admixture of free uric
acid or earthy phosphates, the deposits will not wholly
dissolve on the application of heat, those substances being
nearly insoluble in hot as in cold  water.  The presence of purpurine (104, 217) usually renders the urate
less easily soluble when warmed.
95. When a deposit of urate of ammonia is treated
with a little dilute hydrochloric or acetic acid, it is
decomposed; and minute crystals of uric acid shortly
appear, which may be readily distinguished under the
microscope (194).
SECTION IV.
Urine containing Urate (or Lithate) of Soda.
96. The acid urate of soda (NaO,HIO,C10H2N404) is also
a frequent sediment in the urine, particularly in the
urine of patients taking medicinally the carbonate or
other salts of soda. It may generally be recognized without difficulty under the microscope, usually forming mi* The amorphous deposit formerly described and figured as urate
of ammonia has been proved by Dr. Bence Jones to consist of different
acid urates, among which acid urate of potash occasionally predominates. On washing it with cold water, crystalline uric acid separates,
although none could be perceived in the unwashed deposit.
j See note to (93).




MORBID URINE.                     67
nute globular and sometimes granulated        Fig. 13.
aggregations, with occasionally irregular
and curved protuberances, as shown in            0
Frig 13.*                                             o
97. It resembles the urate of ammonia,
in being soluble in hot water (22, 192),
and also in most of its chemical charac-       o
ters; giving the  same purple-colored    Urate of Soda.
residue when tested with nitric acid and
ammonia (23). It also yields crystals of uric acid, when
treated  with dilute hydrochloric acid  (194).  When
warmed with potash, however, it does not of course give
off ammoniacal fumes (377); and by this, and more especially by its behavior before the blowpipe (202), and by
its microscopic appearance, it may readily be distinguished from the ammoniacal salt. The two salts are frequently found occurring together in the same deposit.
SECTION V.
Urine containing an excess of Hippuric Acid.
98. There is but little that can be said to be characteristic in the appearance of urine in which an excess of
hippuric acid is present. It is most commonly either
neutral or slightly acid to test paper, but occasionally
alkaline; and is in most cases pale and whey-like and of
low specific gravity.  The mode of its detection will be
found described in paragraphs 206, &c.
SECTION VI.
Urine containing an excess of nlucaus.
99. Mucous urine is most commonly very similar in
color to the healthy secretion. It deposits a viscid, tenacious sediment, usually of a dirty yellowish color, consisting chiefly of mucus mixed with epithelium (328);
which, when agitated, does not mix again uniformly with
* The acid urate of soda (NaO,HO,CIOH2N404+2Aq) has been obtained artificially in transparent granules, which might be mistaken,
under- the microscope, for fat-globules, but when washed with water
they assume the ordinary appearance of urate of sodh.




68                MORBID URINE.
the fluid, but coheres together in tenacious, ropy masses,
entangling and retaining numerous bubbles of air.
100. Urine containing an excess of mucus is generally
neutral or slightly acid when passed, unless it has been
retained some time in the bladder, when it is not unfre.
quently alkaline; and when this is not the case, it very
speedily becomes so, owing to the rapid conversion of
the urea into carbonate of ammonia under the influence
of the mucus (11). This change takes place first in the
portion of the fluid which is in contact with the mucous
sediment: this may frequently be seen in specimens of
slightly acid urine, the upper portions of which redden
litmus paper; but if the lower part, more immediately in
contact with the mucus, be tested, it will be found to
restore the original blue color.
101. Mucous urine differs from that containing pus, in
the ropy and tenacious character of the deposit; and also
in not giving any sensible indication of albumen when
tested with heat and nitric acid (254), unless the albumen
be derived from some other independent source, which is
sometimes the case (255). Minute traces of albumen,
indeed, are present in the undiluted -mucous fluid, but
the quantity is so small, that when mixed with urine, it
is incapable of being detected (663).
102. The mucous deposit is frequently found mixed
with a considerable quantity of earthy phosphates or
urates; in which case its opacity renders it more liable
to be mistaken for pus. The true nature of such a mixed
deposit is, however, readily distinguished by microscopic
examination, which should always be had recourse to in
such cases (156, 211, 832).
SECTION VII.
Urine containing an excess of Extractive and Coloring
Matters.
103. Urine containing extractive matters in excess is
usually more highly colored than the natural secretion,
a-large proportion of what is included under the title of
extractive matter, consisting apparently, in most cases,
of the peculiar coloring matters of the urine. When




MORBID URINE.                    69
boiled and subsequently mixed with a little hydrochloric
acid, such urine becomes of a more or less decided red
color (215); and on cooling, usually deposits a quantity
of brownish or bluish-black sediment, which is readily
soluble in alcohol.
104. It is not unfrequently the case, that the peculiar
red coloring matter called purpurine is present in considerable quantity in certain forms of morbid urine.
This, when a deposit of urate of soda or ammonia is also
present, is precipitated withothe urate, giving the sediment a pink or red color (211). When no deposit of
urate exists, the purpurine remains i.n solution, giving
the urine a more or less bloody appearance, which may
sometimes lead to the suspicion that blood is present.
For the methods of identifying purpurine, see paragraphs
216 to 221.
SECTION VIII.
Urine containing an abnormal proportion of Fixed Alkaline
Salts.
105. When these salts are present in excess, they tend
to raise the speifi61gravity of the secretions. The quantity of soluble saline matter may be readily estimated
in the mass, by incinerating the dry residife left after
evaporating a known weight in the urine, and treating the
ash with water, which will dissolve out the alkaline salts,
leaving the earthy phosphates and silica undissolved.*
The aqueous solution is then evaporated to dryness,
ignited and weighed. The individual proportion of the
several salts, which is sometimes a point of considerable
interest, may be determined in the manner described in
paragraphs 66 to 84.
SECTION IX.
Urine containing the Earthy Phosphates in abnormal quantity.
106. The physical characters of urine containing an
excess of earthy pho[sphates vary considerably. The color
is most commonly paleo,and the specific gravity rather low,
but it is also occasionally dark, and of high specific gravity,
* See note to (63).




I70              MORBID URINE.
especially when urea is present in large quantity (87,
301). It is generally slightly acid when passed, but
shor-tly becomes neutral or alkaline (43), when the phosphates are precipitated, often in large quantity, in the
form of a crystalline sediment the color of which varies
from white and gray to a yellow or reddish brown.
When white or gray, the sediment will probably be
found to consist chiefly of phosphates mixed with mucus;
when yellowish or red, it will probably be found to contain, in addition, a certain amount of uric acid, or ur:ate
of soda, or ammonia, most commonly one of the latter.
107. It must be borne in mind that the spontaneous
occurrence of a precipitate *of earthy phosphates, is not
of itself a proof that they are present in excess; nor, on
the other hand, is the non-occurrence of a deposit a proof
that a small quantity only is present. When the urine
is acid, as in health, they may be retained in solution in
considerable quantity, without forming any solid sediment; while if the secretion is neutral or alkaline, a
comparatively small amount of earthy phosphates may
be precipitated in the form of a deposit.
108. When examined with the microscope, deposits of
the earthy phosphates will frequently be found to contain
both the crystalline triple phosphate (MgO,NH140,,EO,
PO), and also phosphate of lime, in the form of an
amorphous powder, or in minute, irregular, rounded particles (43, 44). Minute dumb-bells, like those of oxalate
of lime (Fig. 25), have also been met with.
Crystallized phosphate of lime (Fig. 1,4) (2CaO,HO,
P05) is by no means
Fig. 14.           uncommon in urine.
It may always be obtained  by  _partially
neutralizing the fresh
urine with ammonia,
and setting it aside.
""   Ax  H    i  ~~    109. The quantity
~~-k ~   ~ >of earthy phosphates
w-lich in healthy. urCrystallized Phosphate of Lime.  ie, is usually about




MORBID URINE.                     71
one part in 1000, varies, in disease, from a scarcely perceptible trace to 5,5 in 1000 parts, and is occasionally
even higher.  When present in excess, they may generally be partially precipitated by. warming the urine
(49).
110. It sometimes happens, in certain forms of disease,
that the -earthy phosphates are secreted in much smaller
quantity than is found in healthy urine, and in some rare
cases they appear to be altogether absent.  Whether this
is the case in any specimen of the secretion, may be ascertained by adding to it a slight excess of ammonia, when
if present only in very small proportion, or not at all,
no precipitation will take place; or the ash of the urine
may be digested in dilute hydrochloric or nitric acid, and
the clear acid solution supersaturated with ammonia,
when, if no precipitate is produced; it may be concluded
that no perceptible trace of earthy phosphate is present.
II. Urine containiny one or more abnormal ingredients.
111. The abnormal matters usually found in morbid
urine are: 1, sugar;* 2, albumen; 3, blood; 4, biliary
matter; 5, pus; 6,fat'and chylous matter; 7, semen; 8,
oxalate of lime; 9, cystine and other foreign matters.
Besides the substances just enumerated, various others
may be occasionally.detected in urine, such as arsenic,
antimony, and many other saline and organic matters,
which having been taken into the system  medicinally or
otherwise, and being incapable of assimilation, have
passed through either unchanged, or more or less modified in composition.
SECTION X.
Urine containing Sugar (C,,H,,O,,.)
112. The variety of sugar always present in the urine
of diabetic patients, and hence called diabetic sugar, has
the same chemical composition as that contained in most
* Recent researches (35) have removed sugar from the list of strictly abnormal ingredients of urine, but this does not affect the practical
value of the classification here given, or of tests described in the following section.




72                MORBID URINE.
kinds of fruit, commonly known as grape sugar or
glucose. It appears to contain two equivalents of water
of crystallization, which,may be expelled at a temperature of 212~; so that its composition may be more correctly expressed by the formula (CG2H,2 0,2+ 2Aq).
113. Diabetic sugar may be obtained by concentrating
the urine containing it, by evaporation on a water-bath,
until it begins to dep.osit a crystalline sediment; the
mass is then allowed to cool, on which the greater part of
the sugar crystallizes out. It is then filtered; and when
most of the liquid has passed through, the crystals are
to be pressed between folds of filtering paper, and washed
with a small quantity of cold strong alcohol, which serves
to remove the greater part of the impurities, without
dissolving much of the sugar. The crystals are then
dissolved in hot water, and purified by successive crystallizations, or, if necessary, by boiling with animal charcoal.
114. Diabetic sugar differs from cane sugar (C2111111O),
in being considerably less sweet to the taste, harder- and
less soluble in water; one part requiring about one and
a half of cold water to dissolve it. In dilute alcohol, on
the other hand, it is somewhat more soluble than the
cane variety; but is insoluble in absolute alcohol and
ether. It is usually in the form of granular crystals;
but when crystallized out of a considerable mass of syrup,
is often obtained in needle-like tufts.  When crystallized
from its solution in dilute alcohol, it usually separates in
the form of hard transparent cubes, and occasionally in
square plates.*
115. Strong sulphuric acid dissolves grape sugar, forming a pale yellowish solution; cane sugar, on the contrary,
is almost instantly charred and blackened by the strong
acid.
116. Urine containing sugar is usually characterized
by its high specific gravity, which is frequently from1030 to 1045, and occasionally as high as 1050 and 1055.
* Vohl has met with a case in which a part of the diabetic sugar
in the urine was replaced by inosite. It is also stated that acetone
has been found- in diabetic urine.




URINE CONTAINING  SUGAR.                  73
If, however, the sugar is present only in small quantity,
the specific gravity may not be higher than usual; so
that a moderately low specific gravity is of itself no proof
of the absence of sugar.
117. Diabetic urine has usually, after standing a short
time in a warm atmosphere, a white scum, somewhat
resembling flour, on the surface, consisting of minute,
oval-shaped confervoid vesicles (132), which is highly
characteristic of the presence of sugar, and occasionally
leads to its detection before it has been secreted in sufficient abundance to raise the specific gravity of the urine
to a suspicious extent.
118. This variety of urine is usually paler than the
natural secretion, and frequently possesses a faint greenish tint.  It is most commonly slightly turbid.  WVhen
fresh, it has a faint and rather agreeable odor, somewhat
resembling that of hay.
119. The proportion of urea in diabetic urine is usually
much smaller than that found in the healthy secretion;
but whether the absolute amount secreted differs materially from the normal average, or whether the apparent
deficiency is merely owing to the large quantity of water
passed by diabetic patients thus largely diluting the urea,
has not yet been satisfactorily decided, owing to the
difficulty of correctly estimating the quantity of urea
when mixed with any considerable amount of sugar (334).
120. The proportion of sugar in diabetic urine varies
from a mere trace to from 50 to 80 parts in 1000; and has
been known to amount to as much as 134 parts in 1000.
121. Several tests have been proposed for the detection
of sugar in urine. Of these, the following only need here
be noticed, viz., Tromrner's test, Maumnene's test, J/ioore's test,
the fermentation test, and the -test afforded by the growth
of a microscopic confervoid vegetation, called the torula.
122. Y'rommer's Test.* -This excellent test is founded
on the circumstance that when a solution containing dia* If diabetic urine be not procurable, a few grains of grape sugar
may be dissolved in normal urine for the demonstration of these tests.
Grape sugar may be obtained by boiling white sugar with water and
a few drops of sulphuric acid for a few minutes, neutralizing with
chalk, filtering and evaporating.
7




74                 MORBID URINE.
betic or grape sugar (112), is boiled with a mixture of
potash (If0), and sulphate of copper (CGO,S03), the oxide
of copper ((Cu0) contained in the latter becomes reduced
to the state of suboxide (Cu20), which is precipitated in
the form of a reddish or ochre-colored granular powder.
123. A little of the urine suspected to contain sugar is
placed in a tolerably large test-tube, and mixed with a
drop or two of a solution of sulphate of copper, which
should be added only in sufficient quantity to give the
mixture a very pale blue tint. This will probably cause
a slight precipitation of pale blue phosphate of copper,
owing to the presence of soluble phosphates in the urine
(40); this, however, need not be regarded, as it will not
afterwards interfere with the indications of the test.  A
solution of potash is now added in large excess,* or in
quantity equal to about half the volume of urine employed; this will first throw down a pale blue precipitate
of hydrated oxide of copper (CuO,HO), which, if sugar
is present, will immediately redissolve, forming a purplishblue solution, something similar to that caused in a very
dilute solution of copper by ammonia.
124. The mixture is now to be carefully heated over
a lamp, and gently boiled; when, if sugar is present, a
reddish or yellowish-brown precipitate of suboxide of
copper (CuO) will be deposited in the liquid generally
before the boiling point is reached.,.. If no sugar is present, a black precipitate of the common oxide of copper
(CuO) will be thrown down, totally distinct in appearance
from the suboxide.  It is important, in this experiment,
not to add too much of the sulphate of copper, because,
in that case the suboxide might be mixed with some of
the black oxide (the sugar being capable of reducing only
a certain definite quantity), which would more or less
mask the characteristic color and appearance of the suboxide. This test is extremely delicate, and is capable of
detecting very small traces of sugar in the urine. If very
much sugar be present, the action of the potash upon it
- Or the potash may be added, and the solution filtered from any
deposit of earthy phosphates that may be thrown down, before the addition of the sulphate of copper.




URINE  CONTAINING  SUGAR.                   75
will produce a very dark brown color, which may disguise
the suboxide of copper.  If this be the case, another
portion of the urine may be diluted before being tested.
Since other substances are occasionally found in urine,*
which reduce the oxide of copper, this test cannot be
considered as conclusive, except as to the absence of
sugar. Since the presence of arnmmonia in any considerable quantity interferes with the test, as Dr. Beale originally pointed out, recourse must be had to the yeast test,
if much ammonia be smelt in this experiment.
125. Jaumener's test.-This test is founded on the circumstance that when the sugar is moderately heated in
contact with the bichloride of tin (SnCl2), it is decomposed, and a brownish-black compound, somewhat resembling caramel, is formed. The most convenient method
of applying this test is to saturate strips of merino,
flannel, or some other woollen tissue,t with a solution of
bichloride of tin-prepared by dissolving the salt in about
twice its weight of water, and filtering -after which they
may be dried at a gentle heat on a water-bath, and kept
ready for use.  On moistening one of these strips with
urine, or any other liquid containing sugar, even in a
highly diluted state, and holding it near a fire or over a
lamp, so as to heat it about 270' or 300~ Fahr., it immediately assumes a brownish-black color. The delicacy of
this test is stated to be so great that though ordinary
healthy urine causes no change of color, if ten drops of
diabetic urine be diffused through half a pint of water,
the mixture will immediately give decided indications of
sugar.
126.  1o[bore's test. —Mix a little of the suspected urine in
* Even uric acid produces the same effect, but in general its quantity is too small in normal urine to allow of its being mistaken for
sugar.
t It is necessary in this-test to avoid the use of cotton or linen,
since these substances, being analogous to sugar in composition, undergo also a similar decomposition when warmned with the bichloride
of tinll; and would consequently become blackened, even though no
sugar were present. It will be seen that the utility of this test depends
upon the circumstance that the prepared str-ips can be carried about
so as to render the tests available in a clinical examination. In the
laboratory the other tests are more convenient.




76               BMORBID URINE.
a test-tube, with about half its volume of liquor potassm,
and boil the mixture gently for a minute or two. If
sugar is present, the liquid will assume a brownish or
bistre tint, while little or no heightening of color takes
place when the urine is free from saccharine matter.
127. Bottger's test. —Add to the urine suspected to
contain sugar a few drops of somewhat dilute solution
of nitrate of bismuth (BiO3,3NO,) in nitric acid, then add
carbonate of soda till the solution is alkaline, and boil for
three or four minutes, when, if sugar be present, the
mixture assumes a dark color from the reduction of bismuth, and when set aside, deposits a gray or black precipitate.  With healthy urine a white precipitate of phosphate and carbonate of bismuth is obtained.
128. Fermentation test.-Fill a test tube with the suspected urine, having previously mixed with it a few drops
of fresh yeast, or still better a little of the dried German
yeast; close the open end with a small saucer or evaporating dish, and while gently pressing the latter upon the
tube, invert them, when they will be in
Fig. 15.    the position shown in the figure (Fig. 15).
A little more of the urine is then poured
into the saucer in order to prevent the
escape of any of the liquid from the tube;
and if any bubbles of air have accidentally
been allowed to enter, the exact height of
the upper surface of the liquid in the tube
must be marked with ink, or with a strip
of gummed paper. The tube, with its
ermentation test.  contents, is then set aside in a warm place
having a temperature of about 790 or 800,
for twenty four hours. As bubbles of gas are sometimes
given off by the yeast itself, it is a good precaution to put
the same quantity of yeast into a second tube of equal
size, and fill it up with pure water. The amount of gas,
if any, derived from  the yeast, will thus be rendered
apparent, and may afterwards be deducted from the voluime of gas in the tube containing the urine.
129. If sugar is present, it begins almost immediately
to undergo the vinous fermentation, by which it becomes
converted into alcohol (C4,0IO,HO) and carbonic acid




URINE CONTAINING  SUGAR,                 77
(002), each equivalent of sugar giving rise to the formation of two equivalents of alcohol, four of carbonic acid,
and two of water, thus:C,22,4 0 14=2( C1- QH50,H0)+4C 02+2H0.
The carbonic acid thus formed rises in minute bubbles,
causing gradual and general effervescence, and collects in
the upper part of the tube; at the same time displacing
the liquid, which escapes through the open end of the
tube into the saucer.*
130. That the gas thus formed is really carbonic acid,
may be proved by decanting a little of it under water
into a clean tube, and testing it with lime-water, which
will instantly become milky, owing to the formation of
the insoluble carbonate of lime (CaO,CO2). When the
quantity of sugar present is at all considerable, the urine,
after fermentation, will be found to possess a faint vinous
smell, due to the alcohol formed during the process.
181. If, on the contrary, the urine is free from sugar,
of course no fermentation will take place, and no gas will
be formed in the tube.
132. Test afforded by the growih of the torula —During
the process of' the vinous fermentation of a liquid containing sugar, a delicate white scum gradually collects on
the surface, which, when seen merely with the naked eye,
is so highly characteristic an indication of the presence
of sugar, as frequently to lead to its detection when present only in very small quantity.  If a little of this scum
be examined under the microscope, with a magnifying
power of four or five hundred diameters, it will be found
to consist of minute oval vesicles (Fig. 16), which in the
course of a fewdhours rapidly change their form, becornming longer and more tubular, and giving rise to new
vesicles, which shoot out from the parent body, forming
an irregularly jointed confervoid stem (Fig. 17).  These
again gradually break up into a great number of oval
vesicles, which eventually separate, and fall to the bottom,
where they may be detected by microscopic examination.
* This has been lately proved to be only one of the changes which
are involved in the fermentation of sugar, other substances, such as
succinic acid and glycerine, beiing formed at the same time.
7*




78                  MORBID URINE.
Fig. 16.                       Fig 17.
@tgo       g 0
Torula Yesicles, magnified 400 diameters.  Torula Stem.
Precpitation by tribasic acelae of lead and ammonia.When the proportion of sugar present in urine is very mrinute, the best process for extracting it consists in precipitating the urine, first with acetate of lead, then with tribasic
acetate of lead added in excess, and lastly, after filtering,
with ammonia. This last precipitate is collected upon a
filter, washed, suspended in water, and (lecomposed by
sulphuretted hydrogen. After filtering from the sulphide
of lead, and evaporating, the sugar may be detected by
any of the tests above described.*
Precipitation by potash and alcohol. —If urine contain.
ing sugar be mixed with four volumes of absolute alcohol, allowed to stand for some time, filtered, mixed with
a little alcoholic solution of potash, and set aside for a
day or two, a combination of grape-sugar with potash
separates as a deposit which adheres to the side of the
vessel. The alcoholic liquid having been drained off;
the deposit ma'r be dissolved in water, and tested by any
of the above tests.t
132a. A very remarkable substance has occasionally
been observed in urine, which answers to the test with
the alkaline copper solution in precisely the same manner as sugar, but does not possess the property of re* This process has been employed for the demonstration of the presence of sugar in normal urine, but the circumstance that the indigoproducing body described by Sclhunck (36) is precipitated in the same
way, and yields sugar as a product of its decomposition, nmuch diminishes the value of the evidence which it affords.
t According to Brticke, sugar may be detected in healthy urile by
this process.




URINE CONTAINING  ALBUMEN.                 79
ducing the oxide of bismuth, or of fermenting in contact
with yeast. Its most striking feature is that of absorbing oxygen from the air, and producing a brown color,
when an alkali is added to the solution containing it, so
that urine in which this substance is present becomes
brown at once when shaken with potash, whilst saccharine urine does not become brown until it is boiled.
Boedeker," who first directed attention to this substance,
which he named alkapton, has isolated it in the following
manner: The urine was precipitated by acetate of lead
and filtered. The filtrate was mixed with tribasic acetate of lead, avoiding an excess, the precipitate washed,
suspended in water, and decomposed by sulphuretted
hydrogen. The solution filtered from the sulphide of
lead was evaporated to dryness on the water-bath, and
the residue extracted with ether. On evaporating the
ethereal solution, the alkapton was obtained as a goldenyellow, resinous, deliquescent substance, very easily soluble in water and alcohol. Its solution reddens litmus
slightly, and is unchanged by exposure to air, unless an
alkali is added. The precipitate produced by tribasic
acetate of lead, also becomes brown when exposed to
the air. Alkapton contains nitrogen, but its exact composition has not yet been ascertained.t
SECTION XI.
Urine containing Albumen. 
133. This substance, which is contained, as is well
known, in large quantity in many of the tissues of the
body, and especially in the serum  of the blood (466), is
not unfrequently present in morbid Urine.  Albuminous
urine varies very considerably in appearance and general
characters, being found alkaline, acid, and neutral; high
colored and pale; of high specific gravity and the con* Ann. Ch. Pharm., January, 1861.
t Dr. Johnson has observed the occurrence of alkapton in the urilne
of an infant, his attention being called to it by the brown stains produced on the linen.
I For the purpose of demonstrating the tests, a very little wellbeaten) white of egg may be mixed with some normal urine.




80                MORBID URINE.
trary; so that no general rule can be laid down as to its
usual physical peculiarities, likely to lead to its detection; though, when its presence is once suspected, its detection is easy and simple (139).
134. The quantity of albumen found in urine varies
very much; a mere trace only being sometimes present,
and at others as much as ten or twelve parts in 1000.
135. The most remarkable property of albumen is,
that when a solution containing it is heated to a temperature of about 170~, or higher, it coagulates, and separates
completely from  the liquid; and when this change has
once taken place, it becomes quite insoluble in water.
The coagulated albumen is readily soluble in postash and
other alkaline solutions; and when an excess of alkali is
present, no coagulation takes place on boiling.
186. Albumen is precipitated from its solution by
nitric and hydrochloric acids, but not by phosphoric,
acetic, or tartaric acids, which indeed appear to exercise
a decided solvent action upon it, and, when present, pre.
vent its coagulation on the application of heat.
137. It is also readily precipitated, even from an acetic
acid solution, by ferrocyanide (f~2, Fed3/ + 3Ag) and ferridcyanide (K~,Fe2Uy6) of potassium; and the precipitates
thus formed are easily soluble in alkaline solutions.
138. Chloride of mercury (Hg Cl), alum (A1203,3S03
+Jr O,SO3+24Aq), and many other of the metallic salts,
also cause precipitates in albuminous solutions, which are
compounds of the salt with albumen.  It is precipitated,
too, by alcohol, creasote, tannin, and many other substances.
189. The detection of albumen in urine containing it
is very easy. The suspected urine may be gently boiled
in a test-tube, when' if' albumen is present, it will coagulate, and form a more or less copious white precipitate.
If the albumen is present only in minute quantity, it may
cause merely a delicate opalescence; or, when in larger
quantity, it may separate in curdy flakes; and if very
abundant, may cause the liquid to gelatinize, and become
nearly solid (142).
140. The appearance of a white precipitate on boiling
is not, however, of itself, a sure proof of the presence of




URINE CONTAINING ALBUMEN.                81
albumen in urine, since a white precipitate is also produced by boiling, when the secretion, free from albumen,
contains an excess of earthy phosphates (49a). It is
therefore necessary to add a few drops of nitric acid,
which, in case the precipitate consists of phosphates, immediately redissolves it, but if albuminous, leaves it still
insoluble.
141. To prevent the possibility of error, it is always
advisable to test a separate portion of the urine also with
dilute nitric acid, by which the albumen, if present, will
instantly be thrown down. If the quantity of albumen
is very small, it is possible that the milkiness first
caused by the acid may disappear, but- if a few drops
more of the acid be added, the precipitate will again
separate, and remain insoluble. If both heat and nitric
acid cause a white precipitate, there can be no doubt of
the presence of albumen.
141a. The coagulum may be further tested by Millon's
test, which consists in gently heating it with solution of
nitrate of mercury (HgO,N05) prepared by dissolving
200 grains of mercury in 5 drachms of ordinary concentrated nitric acid, with the aid of heat. Albumen acquires an intense red color when heated with this solution, whilst normal urine is only rendered faintly and
transiently pink. Fibrin, casein, and other members of
the same group of bodies (protein compounds) exhibit
the same behavior.
142. In testing for albumen, it must be borne in mind
that, if the liquid is alkaline to test-paper, the albumen,
though present, will probably not be coagulated on the
application of heat, since coagulated albumen is readily
soluble in alkaline solutions (135). On this account the
urine should first be examined with turmeric or reddened
litmus paper (277), and, if found to be alkaline, neutralized with nitric acid before boiling.
143. It should also be remembered that when the albumnen is present only in small quantity, the addition of
a very slight excess of nitric acid may redissolve it, and
thus lead to the supposition that the precipitate is phosphatic. A  few drops more of the acid, however, will
instantly cause it to reappear, if albuminous; while, if




82                   MORBID  URINE.
really phosphatic, no excess of the acidl would cause it
to do so.*
144. The peculiar casts of
Fig. 18.           urinary  tubes, found in the
o  urine  of  patients  snffering
~ Eoc-':: %:        from  Bright's  disease, consistineg of fibrinous or albuFibrinous Cast. (Dr. G. Johnson.) nrinous matter and entangling blood corpuscles, epithelium, and fatty  globules, have usually the appearance
shown in figure 18.t
SECTION XII.
Urine containing Blood.
145. Urine frequently contains, in addition to albumen,
one or more of the other constituents of the blood (4i50),
and is often more or less highly colored red or brown,
by the presence of the corpuscles and red coloring rnatter.  When the fibrin, in its soluble form, is present, it
usually coagulates spontaneously on cooling, and causes
the urine to become more or less gelatinous soon after it
is passed.  This spontaneous coagulation on cooling may
be considered of itself sufficient proof of the presence of
the fibrin of the blood.
146. The blood corpuscles may generally be detected
both in the coagulumn and also in the superincumbent
fluid, when examined under the microscope (451); occasionally, however, they are almost entirely disintegrated,
so  that little or no trace of their characteristic forr
remains.  They are sometimes found adhering together,
* The result of these tests for albumen may be confirmed by acidulating another portion of urine with acetic acid, and adding ferrocyanide of potassium (137). Chloride of mercury may be added to another portion (138).
In a case of msollities ossium, an albuminoid substance has been
observed in the urine, which was precipitated by nitric acid like albumen, but the coagulum. dissolved on heating, and reappeared as the
solution cooled.  Ferroeyanide of potassium  also precipitated this
substance. Tannic acid gave a precipitate in this urine.
t The presence Of inosite in the urine has been noticed in a case o;
Bright's disease.




URINE CONTAINING  BILTARI   MEATTER.   83
forming little thread-like aggrega-        Fig. 19.
tions; but more frequently floating
detached from each other, looking
like little transparent rings (Fig.   (i 
19).
147. In urine containing blood,' @
the albumen may in all cases be'     ~ 
readily detected by the tests already   i
mentioned  (139)-viz., heat and     _,
nitric acid; but when any of the         Blood in Urine.
coloring matter of the blood is also
present, it will coagulate with the albumen, giving the
coagulum a more or less decided red or brown color.
SECTION XIII.
Urine containing Biliary matter.*
148. WVhen biliary matter is present in urine,t it generally gives a more or less decided yellowish-brown color,
both to the liquid and also to any sediment that may be
deposited from it. The taste also of such urine is remarkably bitter-a peculiarity which furnishes a ready indication of its presence when other tests are not at hand;
though it must not be implicitly relied on, since small
traces may exist in the secretion, without communicating
to it any very decided taste.
149. Pe4tenkofer's test.-Perhaps the best test for the
presence of bile, is that known as Pettenkofer's. If the
urine contains albumnen, it should first be freed from that
substance by coagulation and filtration (135, 151); because albumen, when present in considerable quantity,
would give, with sulphuric acid and sugar, a color resembling that caused by bile. Dissolve a grain or two
of white sugar in the urine to be tested, and add, drop
by drop, about two-thirds of its volume of strong sulphuric acid. If biliary matter be present, a very distinct
and characteristic violet-red color will be produced, which
* A little ox-gall may be added to the urine for the purpose of applying the tests.
t According to Scherer, biliary coloring matter is occasionally present in healthy urine.




84                MORBID URINE.
becomes redder and more intense on the application of
heat. A very small quantity of the biliary matter responds to this test; but a still more delicate mode of applying it consists in mixing the urine with a single drop
of dilute sulphuric acid (1 part of acid to 4 of water),
adding a trace of a solution of sugar, containing 10 per
cent., and evaporating at a gentle heat, when the violet
color becomes evident.
150. When the quantity of bile is small, it is advisable,
before applying the test, to concentrate the urine by evaporation. For this purpose it is first boiled, in order to
coagulate any albumen that may be present (151), and
afterwards evaporated nearly to dryness on a water-bath.
The residue is then treated with a small quantity of boiling water or alcohol; and the solution thus formed, containing any biliary matter that may be present, is allowed
to cool and tested as above.
151. The experiment known as Heller's test is made as
follows: Mix with a little of the suspected urine a few
drops of the serum of blood or white of egg, or of any
liquid containing albumen in solution; and having shaken
them well together, add a slight excess of nitric acid,
which will cause the precipitation of the albumen (186).
If bile is present, the coagulum thrown down by the acid
will have a more or less distinct dull green or bluish
color, quite different from the white or-pale fawn color
which it would otherwise have. When zoifly a small
quantity of biliary matter is present, the urin-e mav be
concentrated, as in Pettenkofer's test (150), the serum or
white of egg being subsequently added to the cold concentrated aqueous solution of the evaporated residue.
152. Gmelin's test.-Pour a few drops of the suspected
urine upon a clean white plate or dish, so as to form a
thin layer of the liquid, and then carefully drop into the
centre, with a pipette, five or six drops of nitric acid.
When bile is present in any considerable quantity, the
liquid becomes successively pale green, violet, pink, and
yellow, the color rapidly changing as the acid mixes with
the urine.  When the bile is present only in small quantity, these colors are not distinctly visible; but unless
the proportion is very minute, a greenish tint is generally




URINE CONTAINING PUS.                  85
perceptible. On concentrating the urine by evaporation,
the appearance may be seen to greater advantage when
only small traces of bile are present (150). The action of
this test appears to depend on the presence of the peculiar brown coloring matter of bile, called biliphbein, or
cholepyrrhin.*
SECTION XIV.
Urine containing Pus.
153. Pus is a substance which in many respects closely
resembles mucus, both in its behavior with reagents, and
still more in its appearance under the- microscope; so
that it is not always easy to distinguish between them;
and when mixed together in the urine, it is frequently
quite impossible to say with certainty
whether or not both are present.  Like      Fig. 20.
mucus, it consists of minute round or
oval granular corpuscles  (Fig. 20),'ga 
floating in the fluid, from which they     Ai         -
separate on standing, and gradually           Q D
sink to the bottom.  These form, in   cl)')
urine containing pus, a pale greenish- PusinUrine, magnified
yellow or cream-colored layer, at the        400 diam.
bottom of the fluid; and, if shaken, the
sediment readily breaks up, and diffuses itself through
the liquid, again gradually subsiding to the bottom when
allowed to stand.  If the urine, however, be decidedly
alkaline, the character of the purulent deposit is changed,
and it assumes nearly the same appearance as mucus
(251, 680).
154. Urine containing pus is met with sometimes neutral, acid, and alkaline. It always contains albumen in
solution, which may be recognized in the filtered urine
by the usual tests, heat and nitric acid (139). This albumen is derived from the liqzor puris, in which it is always
* Briicke recommends a useful modification of this test, which consists in mixing the urine in a tube with dilute nitric acid, and carefully
pouring in sulphuric acid, so as to form a layer at the bottom of the
urine. The rings of color commence from the junction of the two
layers.
8




86                 MORBID URINE.
present (251, 677). The absence of albumen, therefore,
in the urine, may be considered as a strong indication of
the absence of pus; though the presence of albumen is of
itself no kind of proof of the existence of pus, since it
may be derived from other independent sources. Traces
of blood are by no means unfrequent in purulent urine,
giving the sediment a brown or reddish color (145).
155. The chemical and microscopic characters of pus,
and the modes of distinguishing it from  mucus, will be
more fully described further on (247 to 258, 674).
156. The peculiar granular corFig. 21.      puscles, which have been called ~laryge
orgca2ic globules, and which are not
~(,   unfrequently met with in certain
conditions of the urine, especially in
that of pregnant women, closely resemble the corpuscles of mucus and
pus, being granular on the exterior,
Adr'~ M m    a-ind, on the addition of acetic acid,
Large Organic Globules,  develop internal nuclei. They are,
magnified 400 diameters.   however, larger, and are unaccompanied by the albuminous and viscid
fluids, which are characteristic respectively of pus and
mucus (676, 661). The general appearance is shown in
Fig. 21.
157. The smaller circular bodies,
Fig. 22.      which have been occasionally, though
l o -- 0o        much more rarely, found in certain
o          morbid conditions of the secretion,
~         o    and  called small organic yglobules,
o  o    0  are represented in Fig. 22. They
0o     O    O   are spherical and smooth on  the
O        surface, no appearance of granular
L o0 0   structure being apparent, and considerably  smaller than  the  large
Small Organic Globnles.  organic  globules  (156).  They are
unaflbected by acetic acid.




URINE CONTAINING CHYLOTTS MATTER.   87
SECTION XV.
Urine containing Fat and Chylous matter.
158. Urine containing fatty or chylous matter is usually
more or less turbid, and frequently has an almost milky
appearance. Little is known as to the precise nature of
the fatty matter which is thus occasionally met with in
urine, though it is probable that its composition varies
with the circumstances under which it is formed. It
sometimes exists associated with albumen and chylous
matter, sometimes alone. Numerous minute oily globules
may in many cases be seen under the microscope (325),
but it is often so intimately mixed with the albuminous
matter also present, forming a kind of emulsion, that no
trace of oily globules can be detected even with a high
magnifying power. In such cases, the urine may be
agitated with a little ether, which will dissolve the fat;
and the ethereal solution thus formed will separate from
the watery liquid, forming a distinct stratum floating on
the surface. If the ethereal solution be evaporated at a
gentle heat, the fat will be left, and may be readily recognized by the physical peculiarities of fatty substances;
such as immiscibility with water; breaking up into
minute globules when agitated with hot water, &c. Fibrin
is said to be discoverable in urine of this description.
Chylous urine frequently contains minute round corpuscles, resembling the white globules of the blood or
lymph, which at first sight have a good deal the appearance of oil globules, for' which they have probably been
in some cases mistaken.  Their insolubility in ether,
however, shows that they are not always composed of
fatty matter.
159. The peculiar form of mucilaginous or caseous
matter, usually present in the urine of pregnancy, and
which has received the name of Kiestein, gives the urine
containing it a cloudy appearance; and after the lapse
of a few dcays, gradually forms on the surface a more or
less shining pellicle, which in three or four days, as the
urine becomes ammoniacal, breaks up into minute particles, which subside to the bottom. When examined




88                 MORBID  URINE.
under the microscope, the pellicle is found to consist of
minute granular particles, usually  mixed with  great
numbers of prismatic crystals of triple phosphate (44), to
which latter the peculiar shining appearance, somewhat
resembling spermaceti, seems to be due. A few globules
of oily matter, resembling butter, are also occasionally
present.*
Cholesterin has been found in urine in Bright's disease by Dr. Beale.
SECTION XVI.
Urine containing Semen.
160. When semen is present in urine, it may easily be
detected under the microscope, by the appearance of minute animalcules, always
Fig. 23.            found  in  the  spermatic
fluid, and hence called spermatozoa.  They are more
or less oval in form, and
are furnished  with long
and delicate tails, as shown
in Fig. 23.  These spermatozoa, while  in their.      native fluid, enjoy an ac-. tive existence, and move
Spermatoza, and Spermatic Granules,  about at will. In urine,
magnified 400 diameters.  however, unless a considerable quantity of pus is
also present, they are never found alive, the secretion
proving apparently fatal to them.
161. In addition to the spermatozoa, there may generally be recognized in seminal urine a few minute granular
corpuscles, of a round or oval form  (a, Fig. 28), and
rather larger than the bodies of the animalcules. Traces
of albumen also may generally de detected in urine containing semen (264).
* Since Kiestein is not a definite substance, but merely a deposit
of a fungoid growth together with triple phosphate, consequent upon
the rapid alkalescence of the urine, it is not regarded as a conclusive
evidence of pregnancy.




URINE CONTAINING OXALATE OF LIME.   89
SECTION XVII.
Urine containing Oxalate of Lime (CaO,C203+ 2Aq).
162. Urine containing much oxalate of lime is usually,
though by no means always, of a dark amber, and often
of a pale greenish, or citron color. It is in most cases
decidedly acid to test-paper, and is frequently found to
contain an unusually large quantity of epithelial d6bris.
It often contains an excess of uric acid and urates, and
almost invariably also an abnormally large quantity of
urea. Its specific gravity is not often materially different
from that of the healthy secretion, viz., about 1020.
163. Oxalate of lime appears to exist very frequently
in urine, generally in the form of minute and well-definled
octohedral crystals (Fig. 24); but unless carefully looked
for it may readily escape detection, owing to the crystals,
which are very transparent, having almost exactly the
samre refractive power as the urine itself, so that it is not
always easy to distinguish them as they float in the liquid.
The crystals have also nearly the same specific gravity
as urine, in consequence of which they generally remain
suspended in the fluid some considerable time, before
they form a sedimentary deposit at the bottom of the containing vessel.
164. The best way of detecting them is to allow the
urine suspected to contain them  to stand a few hours,
that the oxalate may, in some measure, subside; though
frequently it remains several days without doing so completely, in which ease the urine may be passed through
a filter, when most of the crystals will be retained by the
paper, and may be warmed with a little distilled water,
in the manner described below (165). The greater part
of the liquid is then carefully poured off; and the lower
stratum is placed in a watch-glasss or small porcelain dish
and gently heated over a lamp. In this way the liquid
will become specifically lighter, and in consequence, the
crystals, if present, will gradually subside to the bottom,
especially if a slight rotatory motion be given to the
liquid.  It is now allowed to stand a few minutes, and
tile clear liquid is carefully poured off; or removed by
means of a pipette.
3@




90                 MORBID URINE.
165. A little distilled water may now be added, when
the sediment will become much. more distinctly visible,
owing to the refractive power of the water differing more
decidedly from that of the crystals. The mixture is
again heated, when any urate of ammonia, which is often
also present, will be dissolved; and by pouring off the
liquid, after standing a few minutes, the crystals will be
left at the bottom, and may be removed for the purpose
of microscopic examination, or for testing with reagents.
166. Oxalate of lime,
Fig. 24.             as found in the urine,
is usually in- the form
0~1, ~~~~~of beautifully defined'/7X      I    d      octohedial    crystals
lisp ~~ ~~(Fig. 24), of sizes vary0 go  *               X       ing from1l to -lth
of an inch in diameter.;~a:(.A         When examined with
Octoliedral Crystals of Oxalate of Lime.    polarized light, these
octohedra will be found
to have little or no action upon it, and remain invisible,
or nearly so, when the field is dark.
167. When allowed to dry upon
Fig. 25.     the glass, each crystal appears under
Al    Q     the microscope, especially if the magnifying power is not very high, like
a black cube, having in the centre a
small white square opening, as shown
in Fig. 25.  This curious appearance.:~        is owing to the rays of light, from the
Octohedra of Oxalate of  greater part of the crystal being reLime; seen when dry.  fracted beyond the field of vision.
On again moistening them, the crystals reappear as before in their true octohedral form.
168. Oxalate of lime is not unfrequently met with in
the urine, having the forms shown in Fig. 26, more or
less resembling dumb-bells, with finely striated surfaces.
This form  of oxalate-of-linme sediment, unlike the octohedral variety (166), appears beautifully colored and stri



URINE CONTAINING  OXALATE OF LIME.    91
ated when  examined with  polarized          Fig. 26.
light.*  If these "dumb-bells" be kept
in any liquid medium  for a length of              I I
time, they gradually pass into  octohedra, which  is their more  natural 
form; so that when it is wished  to            X
preserve the dumb-bells, they should
be put up in balsam  in which they  Dumb-bells ofOxalate
will continue to retain their peculiar        of Lime.
form. There are occasionally to be
seen, also, mixed with the octohedra and dumb-bells, a
few  minute, flat, disk-shaped particles, having  a good
deal the appearance of blood-corpuscles (451), for which
they may readily be mistaken; they are, however, usually
much smaller.
169. Oxalate of lime is readily soluble, without effervescence, in dilute nitric and hydrochloric acids, from which
it is again thrown down in the form of a white precipitate,
when the acid solution is neutralized with ammonia or
potash.
170. It is insoluble in both cold and hot water; also
in acetic and oxalic acids; and in solution of potash.
171. When gently ignited  before the blowpipe, it
undergoes little or no blackening, and becomes converted
into carbonate of lime (CaO,CO2), which, when treated
with dilute hydrochloric or nitric acid, dissolves with
effervescence (399). The solution thus obtained by dissolving the carbonate in acid, gives, when neutralized, a
white precipitate with oxalate of ammonia;, but none with
ammonia. If the oxalate be kept intensely heated for
some little time before the blowpipe, the carbonate itself
is decomposed, and caustic lime is formed (402.)
i Dr. Golding Bird imagined that the dumb-bells consisted, not of
oxalate, but of oxalurate of lime (CaO,C6HsN.207). (Urinary Deposits,
fourth edition, p. 219), but the observation that oxalate-of-liine calculi consist often of aggregations of similar dumb-bells renders such
an assumption unnecessary.




92                 MORBID  URINE.
SECTION XVIII.
Urine containing Cystine (C6H1NO4S).
172. Cystine has occasionally, though but rarely, been
found both as a crystalline deposit in urine, and also in
the form of small calculi; in one of
Fig. 27.      which latter it was first discovered by
Dr. Wollaston.  Adeposit of cystine,
H i     when examined under the microscope,
usually appears as, a mass of minute
irregularly  formed  crystals, having,9)  the appearance shown in Figure 27.
To the naked eye, the deposit has a
-     good deal the appearance of pale fawnCystine.     colored urate of ammonia (93), from
which it may be readily distinguished
by being insoluble, or nearly so, in warm water, and consequently not disappearing when the urine containing it
is gently warmed (94).
173. One of the most characteristic properties of cystine is the readiness with which it dissolves in ammonia.
If a little of the ammoniacal solution, thus formed, be
allowed to evaporate spontaneously on a slip of glass, the
cystine is deposited in minute hexagonal crystals, having
the form and appearance shown in Fig. 28.  It must be
remembered that occasionally chloride of sodium crystallizes in octohedral masses (Fig. 29), which in some
Fig. 28.                        Fig. 29.
4    O
Cystine Crystallized from        Crystals of Chloride of Soan Ammoniacal solution.         dium, resembling Cystine.
positions may have at first sight very much the appearalltc of cystine.  The ready solubility of the chloride ill




URINE CONTAINING CYSTINE.               93
water is, however, sufficient to prevent such a mistake.
The crystals of cystine, too, when examined with polarized light, appear beautifully colored, unless very thick,
which is not the case with chloride of sodium. The triangular crystals of triple phosphate (44), which in some
positions somewhat resemble cystine, may be at once
distinguished by their ready solubility in dilute acids
(49, 174).
174. Cystine is insoluble in a solution of carbonate of
ammonia, but soluble in the fixed alkaline carbonates.
It is very sparingly soluble in water, even when warmed,
and insoluble, or nearly so, in alcohol. In acetic acid it
is insoluble, but may be dissolved in nitric and hydrochloric acids.
175. Urine containing cystine has usually a somewhat
paler color than the healthy secretion, with occasionally
a greenish tint. Its specific gravity is most commonly
rather low. It may generally be distinguished, when
fresh, by a peculiar and slightly aromatic smell, a good
deal resembling that of sweet brier; this gradually gives
place to a fetid, disagreeable odor, owing to the occurrence of putrefactive decomposition.
176. Cystic urine is, in most cases, slightly turbid when
passed, and becomes considerably more so as it cools, the
cystine being less soluble in the cold liquid. A small
quantity of the cystine, however, is still held in solution,
and may be precipitated by adding a little acetic acid to
the filtered urine.
SECTION XIX.
Urine containing Iodine and other foreign matters.
177. When the compounds of iodine, as the iodide of
potassium, are taken internally, it is generally found that
nearly the whole of the iodine is carried off by the kidneys, and may be detected, in some form of combination,
in the urine. It may readily be identified by adding to
the secretion a drop or two of yellow nitric acid or very
weak chlorine water, and then testing with a solution
of starch; when, if iodine is present, the liquid will
assume a more or less intense purple color (807, 810).




94      EXAMINATION OF MORBID URINE.
178. Many other substances, taken into the system
either as food or medicinally, pass into the urine unchanged, and may frequently be distinguished by their
peculiar properties. This is especially the case with
many of the vegetable coloring matters, as those of indigo,* madder, beetroot, gamboge, logwood, &c. Some of
these may occasionally give rise to the suspicion of the
presence of blood, but their real nature may generally be
ascertained by examination under the microscope.
179. Besides these coloring matters, various other substances, both organic and inorganic, are occasionally
found in urine. Thus, when any metallic preparation
has been taken internally, traces of the metal, in some
state of combination, may usually be found. The inorganic, and some of the organic acids also, are frequently
to be detected; though, when neutral salts of the latter
have been taken, carbonates of the hases are more usually
found. In addition to these, the odorous principles of
many vegetables appear to pass off unchanged in the
urine, where they may often be recognized by their peculiar smell.
CHAPTER V.
EXAMINATION OF URINE SUSPECTED TO CONTAIN EITHER
AN UNNATURAL PROPORTION OF SOME ONE OR MORE
OF THE USUAL INGREDIENTS, OR ELSE SOME ABNORMAL
MATTER.
180. It often happens, that, owing to some peculiarity
of color and appearance, either of the liquid or sedimentary portion of morbid urine, or from some other circumstance, such as its high specific gravity, we are led to
form some conjecture as to its real nature. When such
is the case, one or two well-selected experiments, such as
those about to be described, will generally be found suffi* A deposit of indigo has been found in the urine in cases in which
that substance had not been taken into the system.




ESTIMATION  OF UREA IN URINE.              95
cient to decide whether or not the suspected peculiarity
really exists.  When, however, the observer is unable to
form a tolerably strong opinion as to the nature of the
urine he is about to examine, he had- better proceed to
test it according to.the directions given in Chapter VI.
SECTION I.
Examination of Urine suspected to contain Urea in abnormal
quantity.
181. When the presence of an excess of urea is suspected, either on account of the high specifie gravity of
the urine (301), or from any other cause, a drop or two
of the liquid should be placed on a slip of glass, and
mixed with about an equal quantity of pure colorless nitric acid.     Fig. 30.
If the urea is present in large             -
excess, there will probably be a
deposition of minute rhomboidal
crystals of the nitrate in the course  "     BL
of a few minutes (Fig. 30), and if
no trace of crystallization is visi-   
ble to the naked eye, the mixture;   \        H
should be examined under the
microscope. If no crystals appear:i1          ___
in the course of half an'hour or
an hour, a few drops of the urine
may be slightly concentrated by
evaporation on a slip of glass, at
a gentle heat; and when cool,          Nitrate of Urea.
mixed as before, with an equal
quantity of nitric acid.  Crystals of the nitrate will now
separate if any considerable quantity of urea is contained
in the urine; and from the rapidity with which the crystals form, together with their abundance, the student will
be able, after a little practice, to form a tolerably accurate opinion as to the relative amount of urea present in
the urine. If a microscope is not at hand, the experiment
may be made, though less delicately, without it. It
must be remembered, that variations in the atmospheric
temperature affect the crystallization of this salt very




96             ESTIMATION  OF UREA.
materially; in cold weather, a specimen of urine will
consequently often be found to afford an abundant crop
of crystals, which, in warm weather, would furnish little
or none. For this reason it is often advisable to cool the
mixture artificially, by immersing the glass containing it,
either in cold water or a freezing mixture: which latter
may be readily made by mixing a little pounded nitrate
of ammonia with an equal weight of water. The nitric
acid may very conveniently be added to the urine in a
thin watch-glass in which it has been previously cooled
by floating the glass upon water. Very brilliant leaflets of the nitrate will be deposited if excess of urea be
present.
Quantitative Estimation of the Urea.
182. Liebig's Method.-This is founded on the circurnstance that urea is capable of combining with nitric acid
and peroxide of mercury, to form a nearly insoluble
compound (CH4N202,NO0,4HgO), which is immediately
precipitated when a solution of urea is mixed with a
solution of nitrate of mercury containing no free acid.
But since this reaction does not take place with the
bichloride of mercury which is formed, by double decomposition, when the nitrate of mercury is added to urine
containing chloride of sodium, it is necessary to remove
the chlorine previously to determining the urea; or a
larger quantity of the mercury-solution would be employed than was necessary to precipitate the urea. The
removal of the chlorine is effected by means of nitrate of
silver, its quantity having been previously determined
by an ingenious application of the principle above stated,
that nitrate of mercury will not precipitate urea, in the
presence of common salt, until a sufficient quantity of
the mercury-salt has been added to convert all the chloride of sodium into nitrate of soda.
The test solutions required for this purpose are:The solution of nitrate of mercury, No. 1, for determining the chlorine;
The solution of nitrate of silver for removing the chlorine;




IN  URINE.                        97
The solution  of nitrate of mercury, No. 2, for determining the urea.
Preparation of the solution of Nitrate of Mercury, No. 1,
employed for determining the Chlorine.-Pure crystals of
protonitrate of mercury are dissolved in moderately
strong nitric acid, and the solution heated until a sample
is no longer rendered turbid by chloride of sodium; the
solution is evaporated, on a water-bath, to a syrupy consistence, and diluted with about 10 times its bulk of
water; it is then set aside for twenty-four hours, and, if
necessary filtered.* In order to graduate the solution, it is
requisite to prepare a saturated solution of common salt;
pure chloride of sodium (colorless rock salt) is powdered,
and digested with water (at the ordinary temperature)
for twenty-four hours, with occasional shaking; so much
salt must be enployed that a considerable quantity may
remain undissolved.4   One hundred and fifty grain-measures of this solution (=47-76 grs. of chloride of sodium)
are poured into a small beaker, and mixed with 45 grs.
of a solution of urea (containing about 4 per cent. of
urea), and with 75 grs. of a cold saturated solution of
pure sulphate of soda; to this mixture the solution of
nitrate of mercury is added, from a burette, with constant stirring, until a distinct precipitate is permanently
formed.4 The strength of the mercury-solution having
been thus ascertained, such a proportion of water must
be added to it that 100 grain-measures may correspond
to I gr. of chloride of sodium.
Pl eparatioln of the solution of Nitrate of Silver employed
* An easier process for the preparation of this solution consists in
adding finely powdered red oxide of mercury to moderately strong
nitric acid, as long as it is dissolved. An ounce of ordinary nitric
acid (sp. gr. 1-42) will dissolve 540 grs. of oxide of mercury, and may
then be diluted with 52 ounces of water.
t One hundred grain-measures of this solution contain 31-84 grs. of
chloride of sodium.
t If any crystalline precipitate should be formed, it may be redissolved by adding a little water. In this process the sulphate of soda
is added for two reasons: firstly, because the compound of nitrate of
mercury and urea is less soluble in saline solutions (as urine for example) than in pure water; and, secondly, in order that the free nitric
acid in the nitrate of mercury may be neutralized by a portion of the
soda from the sulphate, which is thus converted into bisulphate..q




98            ESTIMATION  OF UREA
for'remvoving the Ch7orine.-174'36 grs. of fused nitrate of
silver are dissolved in water, and diluted till the solution
amounts to 6000 grain-measures; 100 grain-measures of
this solution are equal to one grain of the chloride.
Preparation of the solution of Nitrate of Mercury, No. 2,
employedfor determining the Urea.-A solution of nitrate
of mercury is prepared, according to the directions given
above, so as to contain about 25 grs. of nitrate of mercury in 180 grain-measures. In order to graduate this
solution, 20 grs. of pure urea are dissolved in water, and
diluted till the volume of the solution amounts to exactly
1000 grs.; 150 grain-measures of this solution are poured
into a beaker, and the mercury-solution is added from  a
burette till a few drops on a watch glass produce a distinct yellow color with carbonate of soda. This should
be the case after the addition of 300 grain-measures of
the mercury solution, but if the latter be prepared of the
above strength, less than that quantity
Fig. 31. Fig. 32.  ill be required, and so much water must
be added to the solution as will bring it
0  to the proper standard; thus, suppose
0  only 296 grain-measures had been used,
then to every 296 grs. of the solution, 4
20  grs. of water must be added; 100 grs. of
this solution correspond to I gr. of urea.
For the expeditious determination of
40 urea in urine, the analyst should be pro50  vided with the following measures, accurately graduated, for the solutions ernployed:*
-70     1. A pipette (Fig. 31),with a mark upon
the tube indicating the level at which
so o
225 grs. of distilled water would stand.
This is employed for measuring the urine
loo  after precipitation with baryta.
A Pipette. A Burette. 2. A burette (Fig. 32), capable of containing  100 grs. of distilled water, for
the mercurial solution, No. 1. This should  be graduated as accurately as possible.
* These may be obtained fi:om Negretti & Zambra, 11, Hatton
Garden.




IN  URINE.                      99
3. A tall narrow glass measure, capable of containing
1000 grs. of distilled water.
4. A graduated burette, containing 1000 grs., for the
mercurial solution, No 2.
Having the test solutions ready prepared, it is
necessary, before determining the urea in urine, to remove the phosphoric acid, which is effected by means
of a mixture of 2 vols. of cold saturated baryta-water,
an(d 1 vol. of a cold saturated  solution of nitrate of
baryta.* A glass cylinder, of about 1 oz. capacity, is
filled to overflowing with urine, the excess being made
to flow off by covering the cylinder with a glass plate;
two such cylinderfuls are poured into a beaker, and mixed
with one cylinderful of the baryta-solution; the precipitate is filtered off; and the amount of chloride of sodium
contained in 225 grain-measures of the filtrate (= 150
grs. of urine) is then determined by slightly acidulating
with nitric acid, and adding the standard solution of
mercury, No. 1, till the appearance of a cloudiness; 450
grs. more of the filtrate (=300  grs. of urine), are then
measured offi acidulated with nitric acid, and mixed with
a quantity of the standard solution of silver equal to
twice that of the mercury solution employed in the preceding experiment; the liquid is filtered, and half the
sum of the mixed liquors is taken for the determination
of the urea. This quantity (=150 grs. of urine), is
poured into a beaker, and the graduated mercurial solution, No. 2, added from a burette, with frequent stirring,
until no further increase of the precipitate is perceptible
to ascertain if sufficient of the mercury solution has
been added, a few drops of the turbid liquid are removed
with a pipette into a watch-glass, and a few drops of carbonate of soda carefully added down the edge of the
glass;t if, after some minutes, the mixture retain  its
*, The former to neutralize the free acid of the urine, the latter to
decompose the alkaline phosphates. If much ammonia be present in
the urine, it must be expelled by evaporation, with an excess of baryta,
on the water-bath, as it would interfere with the determination of the
urea.
t It is a good plan to place a row of drops of carbonate of soda upon
a glass plate, and to add, from time to time, a drop of the liquid under
examination, until it begins to give a yellow tinge.




100            ESTIMATION  OF UREA
white color, a further quantity of the mercury solution
is to be added, until a fresh sample exhibits plainly the
yellow color after the addition of carbonate of soda.
The number of grains employed is then read off, and
the amount of urea calculated, 100 grs. of the mercurial
solution corresponding to one grain of urea.*
183. The absolute quantity of urea present in urine,
may also be roughly ascertained by evaporating 1000
grains of the urine to dryness on a water-bath, in a
counterpoised porcelain dish, and treating the residue in
the manner described in paragraphs 52 to 56, or by precipitating the concentrated urine (500 grs.) with nitric
acid (16), and weighing the nitrate after washing with
very cold water, and drying at 212~.
183a. A very simple method of determining the proportion of urea in urine consists in decomposing it by
oxidation with a solution of chloride of soda (hypochlorite of soda), and measuring the nitrogen evolved.
Urea. HIypochlorite
of soda.
C2H 4N2023 (NaO,C10)=2C02+4HO- 3Na C+ N,.
To prepare the solution of hypochlorite of soda, 500
grs. of good chloride of lime (bleaching powder) are
stirred with boiling water, filtered, and the residue washed
once or twice with the boiling water. 1000 grs. of crystallized carbonate of soda are dissolved in a little water
and added to the solution, which is then filtered, and
made up to 20 oz. with water. Before determining the
urea in urine, the uric acid and some of the nitrogenized
extractive matters must be precipitated by tribasic acetate
of lead. 300 grain-measures of urine are mixed with
* It has been found that in analyses of urine, when the amount of
urea is increasing, an error is committed, tending to diminish the apparent amount of urea; in order to remove this error, an addition has
to be made-for 225 graiin-measures of urine, and before the test is
applied-of 7'5 grs. of water for every 15 grs. of solution of mercury
which have been used over and above 450 grain-measures, in a prelininary determination. To obviate an error in the opposite direction,
in the more dilute urines, a deduction has to be made of 1'5 grainmeasure for every 75 grs. of mercury solution used less than 450 grs.




IN  URINE.                    101
tribasic acetate of lead till no fresh precipitate is obtained; the solution is boiled and filtered, the precipitate
being washed once or twice with water;* the filtrate and
washings are mixed with a solution of 50 grs. of carbonate of soda in a little water, boiled, and again filtered,
the precipitate being washed tas before. One half of the
cold filtrate and washings is introduced into a flask (capable of holding from five to six ounces) which is then
rapidly filled up to the brim with the solution of chloride
of soda, so that when a cork is inserted, with a narrow
bent tube for collecting the gas, the tube may be filled
with the liquid, to the exclusion of air. The' flask is
then placed in a water-bath, with the tube-dipping beneath
the water in a pneumatic trough, so that the gas may be
collected in a tube graduated to fractions of a cubic inch
(Fig. 33).  Heat is then applied to the water-bath, and
Fig. 33.
when the evolution of gas begins to slacken, the flask
itself may be heated with a spirit lamp until the volunme
of the gas in the graduated tube exhibits no increase
* If a very rapid determination be required, the mixture containing
the precipitate maybe measured before filtration, and half that measure
taken for determining -the urea, so that the washing may be dispensed
witlh.




102               EXAMINATION  OF
after a minute or two. The flask is then removed, the
graduated tube sunk, as far as possible, in the trough,
and when the temperature has fallen to 600 Fahr., the
volume of the nitrogen* is carefully read off,; being corrected, by calculation, for any deviation of the barometric
pressure from thirty inches. 1-549 cubic inches of nitrogen represent 1 gr. of urea.*
IF ammonia be present in the urine, its nitrogen being
evolved, will increase the apparent amount of the urea.
After the experiment, the liquid in the flask should be
tested with a little sulphuric acid, to ascertain (from the
evolution of chlorine) that an excess of chloride of soda
was present.t
The same principle may be more easily, though less
accurately, applied in the following manner (E. Davy).
A measuring tube twelve or fourteen inches long is provided, easily closed by the thumb, and graduated to tenths
and hundredths of a cubic inch. This tube is filled rather
more than one-third full of mercury, and a measured
quantity (50 or 60 grs.) of urine poured into it. The
tube is then quickly filled to the brim with solution of
chloride of soda, closed by the thumb, and inverted
under a sdturated solution of common salt (which, being
heavier than the solution in the tube, prevents its escape)
contained in a small mortar. The tube is allowed to
stand for three or four hours, or until the volume of the
nitrogen ceases to increase, and the amount of urea is then
calculated as above. In this process, the carbonic acid
is retained by the excess of chloride of soda employed.
184. When it is suspected that the urea is present in
smaller quantity than in the healthy secretion, or is even
altogether absent, 2000 grs. of the urine are to be evaporated to dryness on a water-bath, and the dry residue
well stirred with successive small quantities of alcohol,
which will dissolve any traces of urea that may be present. The alcoholic solution is then to be evaporated to
* The carbonic acid having been retained by the large excess of
carbonate of soda employed.
t This method of estimating urea was devised by Leconte.




MORBID URINE.                  103
dryness on a water-bath, and the residue which it leaves
is afterwards treated in the manner described in paragraphs 341 and 342, in order to separate the whole of the
urea, which may, if necessary, be weighed.
SECTION II.
Examination of Urine suspected to contain Uric (or Lit hic)
Acid in abnormal quantity.
185. When urine is suspected to contain an excess of
uric acid, it may be examined in the following manner.
Pour off the clear liquid from any solid deposit that may
have subsided to the bottom, and retain both the solid
and liquid portions for examination.
186. A little of the sediment is placed on a slip of
glass, and examined under the miscroscope; when, if uric
acid is present in it, either alone, or mixed with the
amorphous or rounded particles of urate of ammonia
(193), or other matters, it may be distinguished by its
peculiar crystalline forms, most of the modifications of
which are shown in the annexed figure (Fig. 34).
187. If the sediment consists of uric acid, it will prove
insoluble when the liquid is warmed. If urate of ammonia
is also present, however, the latter will readily dissolve
on the application of heat (192), leaving the crystalline
uric acid unaffected.
188. UTric-acid sediment is insoluble in dilute hydrochloric and acetic acids, but dissolves readily in a solution
of potash, owing to the formation of the soluble urate of
potash (22).
189. When uric acid is moistened with a little tolerably
strong nitric acid, and the residue, after evaporation at a
gentle heat, is treated, when cold, with a drop or two of
ammonia, or exposed to ammoniacal fumes, a beautiful
purple color is developed, owing to the formation of
murexide (23).
190. The clear urine, separated from  the uric acid
sediment (185), being still saturated with the acid, the
latter may be gradually precipitated by adding a few




104:         EXAMINATION OF
Fig. 34.          dro}.s of nitric or hydrochloric acid. The uric acid thus
precipitated usually has the
l l~ Icrystalline forms shown in
the upper and middle part
of the figure.
<7    j  ii E  191. When a deficiency
of uric acid is suspected, the
best way of ascertaining
whether or not such is the
K"    ~  e       case, is to filter one or two
thousand grains of the urine,
Ctig ~a  in order to separate the
mucus andl any other solid
M4  TV    By      matter which it may contain, and which may be separately examined for uric
acid under the miscroscope
(186M), or with  nitric acid
anAd ammonia (189).  The
filtered urine is then evaporated nearly to dryness, on a
water-bath, and the residue
digested with dilute hydrochloric acid, containing one
part of strong acid to eight
or tean of water. Any uric
acid that may be present
will thus be left undissolved,
and may be examined under
the microscope, or otherwise;
and, if necessary, weighed,
after being first dried at a
Crystalline forms of Uric Acid.   temperature of 212~ on a
water-bath.
SECTION III.
-Examination of Ur~ine suspected to contain an excess of Urate
(or Lithate) of Ammnzonia.
192. When a sediment is suspected to consist, either
wholly or partially, of urate of ammonia, a little of the




MORBID URINE.                 105
urine containing it is to be warmed over a spirit-lamp.
If it consists of urate of ammonia unmixed with other
matters, it will readily dissolve as the liquid becomes
warm, and, on cooling, will be again precipitated. When
purpurine is present (104), the urate will probably not
dissolve quite so readily on the application of heat as
when it is unmixed with coloring matter.
193. Under the microscope, urate of ammonia appears
as an amorphous powder, frequently interspersed with
minute round particles larger than the rest, some of which
are occasionally found adhering closely together. (See
Fig. 11, paragraph 91.)  More rarely, it is found in the
form of large masses, containing spicule (Fig. 12, paragraph 92).
194. It must be remembered that phosphate-of-lime
sediment usually has a very similar appearance under
the microscope (108), and may consequently be mistaken
for urate of ammonia, if the microscopic appearance alone be relied       Fig. 35.
upon.  All that is necessary, in       o
order to distinguish between them,     0 
is to add a drop of dilute hydro-  e        i
clloric acid to a little of the deposit on a slip of glass. If it con-  
sists of phosphates of lime, it will
instantly dissolve on the addition
of the acid (49, 322); while, if urate
of ammonia, it will be acted on much    Uric Acid.
more slowly, and in a short time minute crystals of uric acid (Fig. 35) will gradually appear,
having been displaced from the urate by the action of
the hydrochloric acid (196).
NH140,lTO, C;YHA2N  O+HCl =NH4 Cl + 2IO, C10h2N40,4.
195. When uric acid coexists in a sediment with urate
of ammonia, which is of very common occurrence, it
may be distinguished under the microscope, by its crystalline forms (186). The uric acid would also be left undissolved when the liquid is warmed, and may then, if
necessary,be separated by filtration, and further examined.
196. Urate of ammonia deposits are not unfrequently
found mixed with the earthy phosphates, especially when




108              EXAMINATION OF
the urine has at all an alkaline reaction. These will be
left undissolved when the liquid is warmed, and may be
examined under the microscope, and tested with dilute
hydrochloric acid (317, 322).
197. When albumen is present in urine containing a
sediment which is supposed to consist of urate of ammonia,
it mnay, bycoagulating when heated, disguise the solubility
of the urate, and thus lead to an erroneous opinion as to
the nature of the deposit. If, however, the heat be applied
very gradually, the urate of ammonia will be found to
dissolve some time before any of the albumen coagulates;
so that, with care, this source of error may be avoided.
Or if the urine has been inadvertently allowed to boil,
and a precipitation of albumen has taken place, the liquid
may be filtered, whie hot, and the clear filtered solution
will, on cooling, again deposit the urate of ammonia;
which may then, if necessary, be further examined (94,
192).
198. If pus or mucus be contained in the sediment,
together with urate of arnmonia, the urine will not become
perfectly clear on the application of heat; nor will those
substances dissolve on the addition of dilute hydrochloric
acidl. They may, however, be distinguished with the aid
of the microscope (328, 329).
199. When it is required to estimate the quantity of
urate of ammonia in a urinary sediment, a portion of the
latter, derived from a known quantity of the secretion, is
to be boiled with water, and filtered while hot; when the
soluble urate will be separated from any uric acid, earthy
phosphates, &c., that may be also present with it. The
solution is then concentrated by evaporation at a gentle
heat, and allowed to cool; when the urate of ammonia will
again separate in the solid form, and after drying on a
water-bath, may be weighed.
SECTION IV.
Examination of Urine suspected to contain Urate (or Lithate)
of Soda.
200. When gently warmed, the deposit dissolves, like
urate of ammonia, and reprecipitates on cooling.




MORBID URINE.                   107
201. Under the microscope, it usually appears in the
form of small circular, and sometimes semi-crystalline
grains, covered occasionally with irregularly formed
spicula, or granular protuberances, as shown in Fig. 13,
paragraph 96.
202. When ignited before the blowpipe on platinum
foil, it leaves an abundant white fusible residue of carbonate of soda, which is readily soluble in water, forming
a solution which is strongly alkaline to test-paper.
203. If the ignited residue be treated, on a slip of
glass, with a drop of dilute hydrochloric acid, it dissolves with effervescence,  Fig. 36.
forming chloride of sodium; which, if          o
the liquid be expelled by gentle evaporation, is gradually deposited in mi- /    C 
nute cubical crystals, on the glass, and
may be easily recognized with a lens   
or a microscope (Fig. 36).
201. When a little of the deposit
Chloride of Sodium.
previous to ignition, is placed in a drop
of nitric acid on a slip of glass, and the residue, after
evaporation, treated with a little ammonia, in the manner
described in paragraph 23, a purple color is developed,
simila' to that caused under the same circumstances, with
uric acid and urate of amrmonia.
205. Urate of soda may be distinguished from urate of
ammonia, which in chemical properties it miuch resembles, by its microscopic appearance (91, 96); by not being
entirely dissipated by ignition (202, 375); by giving no
ammoniacal fumes when warmed with a solution of potash (377); and by the ignited residue yielding, with
hydrochloric acid, cubical crystals of chloride of sodium,
(203).
SECTION V.
Examination of Urine suspected to contain an excess of
Hippuric Acid.
206. When urine is suspected to contain an excess of
hippuric acid, an ounce or so of the liquid is evaporated
on a water-bath to the consistence of a syrup; which is




108              EXAMINATION OF
then mixed with about half its bulk of strong hydrochloric acid.
The mixture is set aside, and examined after the lapse
of a few hours. If any considerable excess of hippuric
acid is present, it will gradually crystallize at the bottom
of the dish, in fine tufts of needle-like crystals, often
colored pink by the admixture of purpurine, and having
the form shown at a, Fig. 37.
Fig. 37.
d 
Hippuric Acid.
207. If the acid is present in smaller quantity, there
may be merely a few detached microscopic needle-like or
branched crystals, deposited here and there upon the
glass, as shown at b in the figure.
208. Hippuric acid is readily soluble in alcohol; the
alcoholic solution leaving, after evaporation, a crystalline,
residue, which has usually the appearance shown at c,
Fig. 37.
209. It is nearly insoluble in cold water, but readily
soluble in hot. On cooling, the aqueous solution deposits the acid in well-defined prismatic crystals, which
are either detached, as in d (Fig. 37), or in tufts, as shown
at a. These crystals form very beautiful objects under
the microscope; and when examined with polarized light,
develop colors of great variety and brilliancy.
SECTION VI.
Examination of Urine suspected to contain an excess of Mucus.
210. Mucous urine always deposits a viscid, tenacious
mass, having an alkaline reaction (100), and consisting




MORBID URINE.                  109
chiefly of mucus, often mixed with the earthy phosphates,
oxalate of lime, and other matters. If the urine be
shaken the deposit does not again mix uniformly with
the liquid, but remains cohering in ropy masses, which
are very characteristic.
211. When, owing to the admixture of a large quantity of earthy phosphates, the deposit has no longer the
property of cohering together, the microscope must be
resorted to, in order to determine whether or not much
mucus is present; the appearance and abundance of the
peculiar granular corpuscles (315, 328), furnishing a
rough index of the quantity present.
212. It is possible that pus may also be present, in
which case, unless in very smnall quantity, it may generally be detected in the manner described further on (247,
258), where will be found the means of distinguishing
between pus and mucus.
213. If it is wished to determine the amount of mucus
contained in a deposit, in which it is mixed with earthy
phosphates, urates, &c., the sediment must be filtered, and
washed with a little boiling water, in order to dissolve
out the urates; it may then be treated with a little very
dilute hydrochloric acid, which will dissolve out the
earthy phosphates, when the residue of mucus may, after
careful washing and drying on a water-bath or in a hotwater oven, be weighed
SECTION VII.
Examination of Urine stuspected to contain an abnormal
proportion of Extractive Matter.
214. It is often of some importance to be able to identify the presence of an excess of the peculiar yellow
coloring matter, of which the bulk of the extractive matter of urine appears to consist; and also that of purpurine,
which is probably a morbid modification of the yellow
substance.
Yellow Coloring Matter.
215. An excess of the yellow coloring matter may be
recognized by boiling a little of the suspected urine, and
10




110              EXAMINATO10N OF
then adding to it a few drops of hydrochloric acid. A
more or less intense red color is in this way produced;
the intensity of the color indicating the comparative
amount of the yellow coloring matter present. In healthy
urine, a faint lilac or pinkish tint only is caused by the
hydrochloric acid; while, if the coloring matter is in
large excess, an exceedingly intense crimson is produced.
Purpurine.
216. The presence of purpurine, or the red coloring
matter so often met with in cases even of very slight derangement of the system, is easily ascertained. Owing
to its solubility in water or urine, it is never met with as
a deposit per se.
217. Purpurine, however, has a remarkable tendency
to unite with urate of ammonia (104), and whenever a
deposit of that substance is formed in urine containing
purpurine, the latter is invariably precipitated with it,
giving the sediment, which would otherwise be white, or
nearly so, a more or less decided pink or red color.
When purpurine is present in a deposit of urate of arnmonia, the latter is not so easily soluble in hot water,
so that the red deposit does not disappear so readily on
the application of heat, as when no purpurine is present
(94).
218. If a deposit of urates, colored with purpurine, be
digested in warm dilute alcohol, the purpurine-will dissolve, leaving the deposit nearly colorless, and forming a
solution of a yellowish-pink color.
219. Urine containing purpurine, when no excess of
urates is present, has a more or less decided pink or red
color, which may appear at first sight very similar to
blood.
220. Purpurine may be distinguished from blood, when
present in a sediment, by microscopic examination, when
the true nature of the uric deposit will be at once apparent (318, 323), together with the absence of blood disks
(330). When treated with warm alcohol also, the coloring matter will be dissolved out (218).
221. Purpurine when contained in solution in urine,
may be precipitated by adding a little warm  aqueous




MORBID URINE.                   111
solution of urate of ammonia, which will, on cooling,
separate from the liquid, carrying with it nearly the
whole of the coloring matter, forming a pink deposit, and
leaving the urine nearly colorless (217).
SECTION VIII.
Examination of Urine suspected to contain an abnormal
proportion of Fixed Alckaline Salts.
222. When an excess or deficiency of any of the fixed
alkaline salts is suspected to be present, a known weight
of the urine may be taken, from which the proportion of
the substance in question is estimated in the manner described in Chapter II., paragraphs 66 to 84.
SECTION IX..Examination of Urine suspected to contain an abnormal
proportion of Earthy Phosphates.
223. If the suspected urine is neutral or alkaline to
test-paper, a sediment of earthy phosphates may be precipitated even in cases where they do not exist in larger
proportion than in the healthy secretion; so that the
mere occurrence of a small phosphatic deposit is not
necessarily a proof of their excess (107).
224. On warming the urine, the sediment, if phosphatic,
remains undissolved (94, 229).*
225. The earthy phosphates are readily soluble in most
of the dilute acids, especially hydrochloric, nitric, and
acetic.
226. If the acid solution thus formed be neutralized
or supersaturated with ammonia, the earthy phosphates
are immediately reprecipitated (49b).
227. They are quite insoluble in potash, ammonia, and
the alkaline carbonates (49c).
227a. When collected on a filter, washed with water,
and moistened with nitrate of silver, the earthy phosphates assume a bright yellow color.
* If the urine contains albumen, the deposit must be filtered off and
washed before being tested.




112              EXAMINATION  OF
228. A deposit of earthy phosphates may generally be
immediately recognized under the
Fig. 38.      microscope. The crystalline forms.........-::  of the triple magnesian phosphate
have been alreadynoticed (44), and
these are often mixed with the
~!f  amorphous phosphate of lime (Fig.
38). If a drop of dilute hydrochloric or acetic acid be added,
while the sediment is in the field...............of the microscope, the crystals will
Mixed Phosphates.    be seen rapidly to dissolve, leaving
the liquid clear, unless uric acid or
some other matter insoluble in the acid be also present
in the deposit.
229. When urine, containing in solution an excess of
earthy phosphates, is boiled, a portion of them is usually
precipitated, giving the liquid a turbid appearance, resembling the coagulation of a small trace of albumen
under similar circumstances (49, 139). It may readily be
distinguished from albumen, by adding a drop or two
of dilute nitric or hydrochloric acid, which will immediately redissolve the precipitate, if it consists of phosphates,
but if albuminous, will not affect it.  When the precipitate is found to dissolve on the addition of the first drops
of acid, it is advisable, before concluding that albumen
is not present, to acidify the mixture more strongly, since
the coacgulurn of albumen, when verv small in quantity,
occasionally dissolves on the first application of acid, but
is wholly reprecipitated on the addition of a few drops
more of the acid (140 —143).
230. If the absence or a deficiency of the earthy phosphates is sfsp~ected, the urine may be treated with a slight
excess of ammonia, when, if no precipitate occurs, it may
be inferred that they are either altogether absent or else
present in very small quantity.
231. In order to ascertain, in such a case, whether or
not any traces of them are present, a pint or two of the
urine may be evaporated to dryness, and the residue,
after incineration, digested with dilute hydrochloric acid,
which will dissolve out the earthy salts, if any are present.




MORBID URINE.                  113
The acid solution thus obtained is then filtered, and
supersaturated with ammonia, when, if any earthy phosphates are present, they will be thrown down in the form
of a white precipitate (49b).
Quantitative determination of the Earthy Phosphates.
232. When it is required to estimate the proportion of
earthy phosphates in a deposit containing uric acid and
other matters, a portion of the sediment, derived from a
known quantity of urine, is first washed with a dilute
solution of ammonia, and then digested with dilute
hydrochloric acid, until the latter ceases to dissolve anything further. The acid solution of the earthy salts, thus
obtained, is separated from the insoluble matter by filtration, and then supersaturated with ammonia, which will
throw down the whole of the earthy phosphates. The
mixture after standing a short time, to allow the magnesian phosphate wholly to separate, is to be filtered; and
the precipitate, after drying at a gentle heat, is to be
weighed, when its weight will represent the amount of
deposited earthy phosphates in the quantity of urine from
which it was derived.
SECTION X.
Examination of Urine suspected to contain Sugar.
233. When urine is suspected to contain sugar, it may
be examined by paragraphs 122 to 10. If any white
scum or sediment is present, it should also be examined
for the torula vesicles, under the microscope (132).
234. The method of estimating the quantity of sugar
contained in diabetic urine will be fully described in
Chapter VII.
SECTION XI.
Examination of Urine suspected to contain Albumen.
235. A little of the suspected urine is to be gently
boiled in a test tube. If any albumen is present, it will
be coagulated, forming a more or less copious white
deposit in the liquid. The precautions necessary for the
10-x



114             EXAMINATION  OF
success of this experiment have been already noticed in
paragraphs 139 to 143.
236. To another portion of the urine add a few drops
of nitric acid, observing the precautions mentioned in
paragraph 143. If a precipitate or milkiness be produced by the acid, and also by boiling (235), the presence
of albumen in the urine may be considered certain (141).
237. The proportion of albumen in urine may be
estimated with tolerable accuracy by boiling a known
quantity of the secretion, and separating the coagulum
by filtration; the insoluble matter is then washed with a
little dilute nitric or hydrochloric acid, in order to dissolve out any earthy phosphates that may have been
precipitated (140), dried on a chloride of calcium bath,
at a temperature of 240~ or 250~, and weighed.
238. If the quantity of albumen is so small as not to
form a tolerably decided coagulum when boiled, but only
to render the liquid opalescent, it will be hardly necessary
to proceed with the quantitative determination.
239. The method of making a complete quantitative
analysis of albuminous urine will be fully described in
Chapter VII.
SECTION XII.
Ealxamination of Urine suspected to contain Blood.
24-0. When, from its peculiar red or brown color, or
from other circumstances, the presence of blood is suspected in urine, it may first be examined under the
microscope for any blood corpuscles that may be contained in it (146). If no coagula have separated (145),
the liquid should be allowed to repose for a short time,
inrorder to let the corpuscles subside to the bottom; and
a drop then taken from the bottom of the vessel will
generally be found to contain an abundance of the corpuscles, more or less modified in form and appearance
(456).
241. When so much blood is present as to give the
urine a decidedly red color, it will probably be unnecessary
to wait for the subsidence of the corpuscles; and a drop




MORBID URINE.                  115
of the liquid taken indiscriminately will usually be found
to contain sufficient for microscopic examination.
242. If the blood has coagulated, either in the bladder
or subsequent to emission, it is most probable that the
greater portion of the blood-corpuscles will have been
entangled in the coagula, and may be forced out by gentle
pressure under a strip of thin glass, so as to be made
visible with the help of the microscope.
243. The urine should also be tested for albumen by
heat and, nitric acid, in the manner already described
(139-143). The coagulated albumen will probably, in
this case, be more or less highly colored, owing to the
presence of the coloring matter of the blood (147, 455).
If the urine already contains coagula, or other solid
matter, it should be separated from them by filtration,
before being tested for albumen; as their presence would
tend to mask the appearance of coagulation.
244. If the urine contains much blood, it may probably
become spontaneously gelatinous, owing to the coagulation of the dissolved fibrin (145, 448). This coagulurn
should be examined under the microscope, since a somewhat similar gelatinous character might be occasioned
by the presence of a considerable quantity of mucus (101);
or, if the urine be alkaline, of pus (251, 680). The
coagulum of fibrin, when pressed between glasses, is
usually found to be composed of minute amorphous
particles, with a few red blood-corpuscles; quite different
in character from the granular mucus-corpuscles (1 46,328).
245. Urine containing bile or purpurine (148, 104), has
sometimes nearly the same color and appearance as when
blood is present, and may, without care, be inadvertently
mistaken for it. If no trace of blood-corpuscles can be
detected under the microscope, we should, before deciding
that blood is present, prove that the color of the secretion
is not due to purpurine, or biliary matter, by applying
the tests described for the detection of those substances,
in paragraphs 219-221, 246, &c.




116             EXAMINATION  OF
SECTION XIII.
Examination of Urine suspected to contain Biliary Matter.
246. When urine is suspected to contain biliary matter,
it may be examined by Pettenkofer's and Heller's tests,
described in paragraphs 149 and 151. If these fail to
afford indications of it in the urine, the latter should be
concentrated by evaporation on a water-bath, and the
strong aqueous or alcoholic solution of the evaporated
residue again tested (150).
SECTION XIV.
Examination of Urine suspected to contain Pus.
247. When pus is contained in urine, unmixed with
any considerable quantity of mucus, it may readily be
distinguished under the microscope by its containing the
peculiar nucleated pus-granules (153, 678). These particles, when the urine is allowed to stand a short time,
gradually subside to the bottom of the liquid; and when
shaken, again mix readily with the urine, in which
respect a deposit of pus differs essentially from one of
mucus; the latter forming, on agitation, tenacious ropy
masses, which do not again mix uniformly with- the
liquid (99).
248. As purulent deposits frequently appear to the
naked eye very similar to those of the-earthy phosphates,
(106), and as it is often difficult to distinguish between
pus and mucus when they coexist in a specimen of urine,
I will mention the more characteristic tests by which
purulent deposits may be most readily identified.
249. It must be remembered that the form and general
appearance of the pus- and mucus-corpuscles vary considerably under different pathological conditions of the
patient; so that it is not uijfrequently impossible to
distinguish between them. The granules of pus appear,
indeed, to be identical with those of mucus; the difference
between the two substances being in the composition of
the fluid in which the particles float (661, 676).
250. Under the microscope, with a power of about 400




MORBID URINE.                  117
diameters, the  pus-granules          Fig. 39.
have the appearance repre- 
sented at a, Figure 39; and on
the addition of a little dilute    V. G OR
acetic acid, they become much!I'n  % 
more transparent, and in each
corpuscle one or more internal
nuclei are rendered visible,         Pus-Granules.
having the appearance shown
at b in the figure. The granule of pus will be found to
float about freely in the liquid (678, 156).
251. When the urine is alkaline, the character of the
pus contained in it is different; being then thick and
gelatinous, closely resembling mucus (6i0).
252. The granules of mucus present almost precisely
the same appearance under the microscope as those of
pus, but are usually, perhaps, rather smaller, and less
distinctly granular on the surface. The addition of dilute
acetic acid renders visible the interior nuclei, as in the
case of pus (250). The acid, however, coagulates the
fluid portion of the mucus, owing, probably, to the precipitation of the mucin, before held in solution by a small
quantity of akali (663). In the case of urine containing
only a small quantity of mucus, it is uncertain whether
this phenomenon of coagulation will be seen, on account
of the dilution of the mucous fluid, and also because the
coagulation may have been already occasioned by the
presence of the large quantity of water (663). When,
however, the quantity of mucus is tolerably abundant
the coagulation by acetic acid furnishes a very characteristic reaction.
253. The earthy phosphates, which to the naked eye
sometimes closely resemble pus, may be at once distinguished under the microscope by their crystalline form
(43), and also by being readily soluble on the addition of
dilute acetic acid (228.)
254. The liquor puris, in which the pus-granules float,
always contains albumen in solution (676). This may be
readily detected by the tests of heat and nitric acid,
already described (139); unless, indeed, the quantity of




118              EXAMINATION OF
urine is so large, compared with that of the pus contained
in it, as to have rendered it too dilute.
255. The fluid portion of mucus, on the contrary, contains no albumen, or merely a minute trace (663), and
consequently when diluted with urine undergoes no
coagulation when heated, or tested with nitric acid. It
is, however, very possible that urine containing an excess
of mucus, and no pus, may also contain albumen; so
that the mere presence of albumen in the secretion is not
necessarily a proof of the presence of pus (101).
256. A certain quantity of fatty matter, readily soluble
in ether, is always present in pus (676, 678), but seldom,
and in much smaller proportion, in mucus (663). If,
therefore, the deposit, or the residue after evaporation, be
boiled with a little ether, and the ethereal solution thus
obtained is found to yield, on evaporation, small globules
of yellowish fat, it is probable that pus is present.
257. A deposit of pus, when treated with a solution
of ammonia or potash, becomes converted into a thick
gelatinous mass, often sufficiently tenacious to allow the
tube containing it to be inverted without any of the
mixture flowing out. This reaction is very characteristic.
258. Urine'containing pus is most commonly either
neutral or slightly acid, and becomes alkaline very
slowly. Mucous urine, on the contrary, even if acid,
when it is passed, quickly becomes ammoniacal, and alkaline to test-paper (100). Tubercular matter deposited in
the urine might at first be mistaken for pus; a minute
examination, however, will show d6bris of cells, and
sometimes crystals of cholesterin.
SECTION XV.
Examination of Urine suspected to contain Fat or Chylous
Matter.
259. Urine suspected to contain fat, may be examined
with a tolerable high power under the microscope, when
it is occasionally found to contain minute oil-globules
(158, 325). This, however, is not always the case; so
that the best way of proving the presence of fatty matter,
is to agitate a little of the suspected urine with about half




MORBID URINE.                  119
its bulk of ether; which will separate the fat from the
watery fluid, forming, usually, a yellowish solution, which
gradually rises to the surface. The ethereal solution
thus obtained may then be cautiously evaporated on a
water-bath, when the fat or oily matter will, if present,
be left behind; and may, if necessary, be tested as to its
oily nature, by shaking up with hot water; when, if oil
or fat, it will break up into minute globules, immiscible
with the water (158).
260. Chylous urine is usually so peculiar in appearance
that it can hardly be mistaken for any other morbid condition of the secretion. Under the microscope, it appears
to be chiefly composed of amorphous albuminous matter
in a minute state of division, mixed occasionally with
globules resembling those found in the lymph and chyle.
On agitation with ether, it will yield abundant traces of
fatty matter, and distinct oily globules may occasionally
be distinguished.
261. This form of urine always contains albumen in
solution. A portion of this, or more probably a little
soluble fibrin (145), not unfrequently coagulates spontaneously after emission, giving the urine a gelatinous or
semi-solid consistence. The presence of albumen may
be shown by applying to the urine, rendered clear by
filtration, the tests of heat and nitric acid (235).
262. If it is required to ascertain the quantity of fatty
matter in any specimen of urine, a known weight of the
secretion may be agitated with successive small quantities
of ether; and the ethereal solution thus obtained will
leave, after evaporation, the fatty matter which it had
dissolved. This is to be dried on a water-bath until it
ceases to lose weight.
SECTION XVI.
Examination of Uri'ne suspected to contain Semen.
263. Microscopic examination is the only trustworthy
means of determining whether or not any traces of semen
are contained in urine. The urine should be well shaken,
and then left to stand a short time, in order to allow the
flocculi of mucus and spermatozoa to subside. The greater




120              EXAMINATION OF
part of the fluid is then poured off; and a drop containing
the sediment, taken from the bottom, and examined under
the microscope, with a magnifying power of at least four
or five hundred diameters. If semen is present, the spermatozoa always contained in that secretion will then be
visible (160), together, probably, with the peculiar seminal granules also found in the spermatic fluids (161).
264. Traces of albumen, also, may generally be detected
in seminal urine, by the application of heat and nitric acid
(235&.
SECTION XVII.
Examination of UTrine suspected to contain Oxalate of Lime.
265. When the presence of oxalate of lime is suspected,
the urine should be allowed to stand some little time, in
order that the sediment may partially subside. A little
of the liquor taken from the bottom of the vessel is then
treated in the manner described in paragraph 164, and
examined under the microscope; when, if present, the
oxalate will be seen in the form of octohedral crystals
(166, 168), or of the dumb-bell shape.
266. Oxalate of lime is insoluble in acetic acid, but
dissolves without effervescence in dilute hydrochloric
acid, and is again precipitated unchanged, when the acid
solution is neutralized or supersaturated with ammonia
or potash.
267. If the oxalate of lime deposit be gently ignited,
and the residue after ignition treated with dilute hydrochloric acid, it will be found to dissolve with effervescence,
having been converted, during ignition, into the carbonate
of lime (39)9).
268. When it is required to estimate the amount of
oxalate of lime sediment, it may, if unmixed with other
deposits, be separated by filtration from a known quantity
of urine, and weighed. When mixed with earthy phosphates or urates, the deposit, after filtration, may be
washed with a little dilute acetic acid to dissolve out the
phosphates (49b); the mixture is then filtered, and the
insoluble portion digested in dilute hydrochloric acid,
which will dissolve the oxalate of lime,leaving undissolved




MORBID URINE.                   121
any uric acid that may be present.  The acid solution is
then filtered, if necessary, and supersaturated with ammonia; by which the oxalate will be again precipitated.
It may then be collected on a weighed filter, dried on a
water-bath, and weighed.
SECTION XVIII.
Examination of Urine suspected to contain Cystine.*
269. The presence of cystine may generally be identi
fled by means of the microscope (172), especially after
the deposit has been dissolved in ammonia, and allowed
to crystallize, either spontaneously or with the aid of a
very gentle heat, from the ammoniacal solution (270).
270. Treat a portion of the suspected deposit with a
little solution of ammonia; if it is cystine, it will be
found readily to dissolve. Place a drop of the ammoniacal
liquid on a strip of glass, and allow it to evaporate spontaneously. The peculiar hexagonal tabular crystals of
cystine thus obtained, are very characteristic (173).
-271. Neutralize the rest of the ammoniacal solution
formed in 270 with acetic acid; the cystine, if present,
will be precipitated (174).
272. Cystine may be distinguished from urate of ammonia, which it often closely resembles in external
appearance, by being insoluble, or nearly so, when the
urine containing it is warmed; while urate of ammonia
readily dissolves (172, 94).
273. It may be distinguished from the earthy phosphates by its'insolubility in acetic acid (174); by its
appearance under the microscope (317, 320); and also by
its ready solubility in ammonia (173).  From  chloride
of sodium, cystine may be distinguished by its sparing
solubility in water (173).
274. If cystine be boiled with a little caustic potash,
and the solution tested with acetate of lead, a black
precipitate of sulphide of lead will be produced; in
* In cases where cystine has been excreted, it has generally been
found to be most abundant in the morning urine.
11




122               EXAMINATION  OF
consequence of the large amount of sulphur contained
in the cystine (C6H6NO4S).*
SECTION XIX.
Examination of Urine suspected to contain otherforeign
Matters not included in theforegoing sections.
275. When the presence of any other kind of foreign
matter is suspected in the urine (180), such as metallic
salts, iodine, inorganic or organic acids, &c., a few tests,
such as hydrosulphuric acid, hydrosulphate of ammonia,
&c., will generally lead to their detection without much
difficulty. (See Parts IV and V; also my'Introduction to
Practical Chemistry,' Parts II and III.) If the suspected
substance is organic, either the urine itself or the evaporated residue may be tested; but when a non-volatile
inorganic substance is to be looked for, it is generally
advisable to incinerate the evaporated residue, and test
the ash for the substance in question.
CHAPTER VI.
EXAMINATION OF MORBID URINE, THE NATURE OF WHICH
IS ALTOGETHER UNKNOWN.
276. WHEN a specimen of urine is suspected to differ
in some respect from the healthy secretion, it will generally be found easy, by means of a very few simple experiments, such as those which I am about to describe, not
only to ascertain whether or not such is the case, but
also to discover the nature of the particular morbid condition in question; whether it be that one or more of the
normal constituents of healthy urine is present in an
* According to Stadeler, tyrosine (C8H,,I NO6) has been found in the
form of a sediment in urine, in extreme derangement of the liver. It
dissolves in boiling water, and is deposited in fibrous crystals on cooling. Its solution gives a red flocculent precipitate with pernitrate of
mercury.




MORBID URINE.                 123
abnormal proportion, or whether it be due to the presence
of some substance which is never found in the healthy
secretion. In such an examination, the microscope will
be found to affobrd much valuable and ready assistance,
the simple microscopic inspection of a deposit often rendering its true nature at once apparent. Whenever,
therefore, the student has access to one, he will do well
to avail himself of it as much as possible; and he will
soon find that, with a little experience, he will be able
readily to discriminate between the more common forms
of urinary deposits.
For the method of distinguishing the several forms of
deposit under the microscope, see paragraphs 315 to 332.
SECTION I.
Examination of Urine containing some solid Deposit.
277. The urine may be first tested with blue litmus
paper, which should be allowed to remain for some time in
the urine; if acid, the color will change to
red, or reddish purple. Should the blue    Fig. 40.
color remain  unchanged, test it with
yellow turmeric or reddened litmus pa-       la
per; if the urine is alkaline-owing, pro.
bably, to the conversion of urea into carbonate of ammonia (11) —the turmeric wvill
become brown, and the reddened litmus
blue, while, if the color in both cases
remain unaltered, the urine may be considered neutral.
278. The specific gravity of the urine
may then be taken.
279. This is most readilydone by means
of the urinometer, which is a little instrument constructed on the principle of the
hydrometer, the usual form of which is
shown in the annexed figure. The tube, when used, is
simply immersed in the urine at the temperature of 60O
Fahr.; and when it has come to rest, the number on the
graduated scale, which stands at the level of the liquid,
when added to 1000, will represent the specific gravity




124              EXAMINATION  OF
of the fluid. For example, if the level of the liquid
stands at 5 on the scale, the specific gravity of the urine
will be 1005; if at 30, it will be 1030, and so on (301).
280. If a urinometer is not at hand, the specific gravity
of the urine may be taken by means of a bottle, or even
with a small piece of glass.*
281. The deposit may -now be for the most part separated from the urine, by allowing it to subside for a
short time in a tall glass, and then pouring off the clear
liquid, or drawing it off with a syphon or pipette. The
portion of urine containing the sediment in suspension
may first be examined. For the mode of examining the
clear liquid separated from it, see paragraphs 800 to t14.
Examination of the Solid Deposit.
282. If, owing to some characteristic peculiarity in the
appearance of the deposit, or of the urine containing it,
or from other circumstances, the observer has reason to
suspect the nature of the sediment, he may at once proceed to apply the tests for the suspected substance, according to the directions given in Chapter V. At first, however, and until he has had some little experience on the
subject, he will do well to adopt. some such method of
examination as the following.
283. In the great majority of cases, the deposits contained in urine will be found to consist of one or other
of the following substances-viz., earthy phosphates, uric
acid, urate of soda or ammonia, or oxalate of lime; sometimes alone, sometimes two or more mixed with each
other, or with mucus or other matters. The first experiments, therefore, should be directed to the detection of
these four substances.
284. Put a little of the urine containing the deposit
into a test tube, and warm it gently over a lamp. IF IT
READILY DISSOLVES, it is probably URATE OF SODA OR
AMMONIA (192, 200); in which case one or two of the
more characteristic tests for those substances may be
applied, and the deposit may be examined under the
t See Introduction to Practical Chemistry, fourth edition, p. 56.




MORBID URINE.                 125
microscope, in order to confirm or correct the first reiult.
If purpurine is present with the urate, which may be
known by its pink or reddish color, the deposit will probably not dissolve so immediately on warming, as when
the coloring matter is absent (192). If the deposit does
not dissolve when gently warmed, nor yet when heated
nearly to boiling, it must be further tested as follows.
285. IF  THE DEPOSIT DOES NOT DISSOLVE  WHEN'
WARMED, add to a few drops of the sedimentary urine in
a test tube, a little acetic acid.
286. IF THE DEPOSIT DISSOLVES IN ACETIC ACID, it
probably consists of EARTHY PHOSPHATES; the nature of
which, whether consisting of phosphate of lime, or triple
phosphate, or a mixture of both, may be distinguished
by submitting a little of the deposit to microscopic examination (228, 317, 322). (Confirm 47, 225-227.)
287. IF THi DEPOSIT PROVES INSOLUBLE IN ACETIC
ACID, test another portion with a little dilute hydrochlorio acid. If it DISSOLVES IN THE ACID, and the acid solution thus obtained gives, when neutralized with ammonia,
a white precipitate, it is probably OXALATE OF LIME (266).
(Confirm 819, 267.)
288. IF THE HYDROCHLORIC ACID FAILS TO DISSOLVE
THE DEPOSIT,' it may be tested for URIC ACID by means of
nitric acid and ammonia, in the manner described in paragraph 23. Uric acid may also be readily distinguished
under the-microscope (3 L8). (Confirm 187, 188.)
289. If the deposit proves to consist neither of earthy
phosphates, uric acid, urate of ammonia, nor oxalate of
lime, it must be examined for the other matters which
are occasionally, though less frequently, met with in morbid urine, and which have been already noticed in Chapters IV and V. It must be remembered that, in perhaps
the majority of cases, urinary deposits do not consist
exclusively of any one substance, but contain two or more
mixed together; as when the earthy phosphates occur
associated with an excess of mucus. The action of the
several tests may frequently in this way be more or less
masked, and when taken alone, may lead to erroneous
conclusions. In such cases, the microscope will be found
11*




126             EXAMINATION OF
of infinite value, and should always, when available, be
employed (315).
290. If the deposit sinks readily to the bottom of the
vessel, forming a PALE GREENISH YELLOW  SEDIMENT,
which, on agitation, is again diffused readily and uniformly in the liquid, it probably consists of Pus (247).
(Confirm 250, 254, 256, 257, 156.)
291. If, on the other hand, the deposit is TENACIOUS
AND ROPY, not mixing uniformly with the liquid when
shaken, it probably contains an excess of Mucus (210).
(Confirm 211, 100, 156.)
292. If the deposit is DARK COLORED, brown, or red,
and has been found not to consist of urate of ammonia
colored with purpurine (284), it probably contains BLOOD;
in which case the clear portion of the urine (281) will
give indications of albumen when heated, or when tested
with nitric acid (243). (Confirm 240, 242, 245.)
293. When the deposit is WHITE OR NEARLY SO, having
proved insoluble when warmed (284), and also when
treated with dilute hydrochloric and acetic acids (285,
286): and is found to be readily SOLUBLE IN A SOLUTION
OF AMMONIA, the ammoniacal solution yielding on evaporation HEXAGONAL CRYSTALLINE PLATES, it is probably
CYSTINE (272, 270, 273).
294. If the deposit is PALE YELLOW, tolerably soluble
when warmed (200), but does not appear to consist of
urate of ammonia, owing to its yielding no ammonia
when warmed with a solution of potash (205), and appearing under the microscope, not as an amorphous sediment but in small irregularly shaped roundish or oval
particles, with or without projecting protuberances (324),
it is probably URATE of SODA. (Confirm 202, 203, 204.)
295. If, when a little of the urine is agitated with a
little ether in a test tube, and the ethereal solution, after
separating from the watery portion on which it floats, is
found to leave, after evaporation at a gentle heat, a residue of fat or oily matter, the presence of FAT may be
inferred (259). (Confirm 325.)
296. If the urine is OPAQUE AND ALMOST MILKY in
appearance, yielding traces of fat when treated with
ether; and is found, when examined under the micro



MORBID  URINE.                   127
scope to contain an abundant white amorphous or granular deposit of alburnen or fibrin, together probably with
small round colorless corpuscles, it probably contains
CHYLOUS MATTER (260).  (Confirm 261, 826.)
297. If, on examination under a microscope of high
magnifying power, minute ANIMALCULES are visible, having the appearance shown in Figure 23, page 88, it is
probable that semen is present (160). (Confirmrn 161,
264.)*
298. The following table may serve to facilitate the
examination of deposits with reagents. It must, however,
be borne in mind, that until the observer has had some
little experience in the action of the several tests, he must
not depend too much on the result of any one experiment; but must, in all cases, confirm his suspicions by
one or more corroborative tests.
TABLE
For facilitating the Examination of Urinary Deposits by means of
Chemical Tests.
299. Test first for the eartlhy phosphates, uric acid,
urates of soda and ammonia, and oxalate of lime (288).
1. THE SEDIMENT DISSOLVES WHEN WARMED; Urate of
soda or ammonia (200, 281). NOT SOLUBLE WHEN
WARMED; See 2.
2. SOLUBLE IN ACETIC ACID; Earthy phosphates (286).
INSOLUBLE IN ACETIC ACID; See S.
3. SOLUBLE IN DILUTE  Y1)DROCHLORIC ACID; Oxalate
of lime (287). INSOLUBLE IN DiLUTE HYDROCHLORIC ACID; See 4.
4. PURPLE WITH NITRIC ACID AND AMMONIA; U'ric acid
(28b).
* Specimens of urine are occasionally met with, holding in suspension a deposit (either amorphous or crystalline) which is insoluble in
acids aiid alkalies as well as in alcohol and ether; but since it is at
least diminished by shaking with hydrochloric acid and ether, it appears to consist of an earthy salt of one of the fatty acids.




128               EXAMINATION OF
If the deposit proves to be neither of the above, it is
probably one of the following:5. GREENISH YELLOW  DEPOSIT, EASILY DIFFUSED ON
AGITATION; Pus? (290).
6. ROPY AND TENACIOUS; A/Itcus? (291).
7. RED OR BROWN; NOT SOLUBLE WHEN WARMED  THE
FLUID PORTION COAGULABLE BY HEAT AND NITRIC
ACID; Blood?. (292).
8. SOLUBLE IN AMMONIA; THE SOLUTION LEAVING ON
EVAPORATION, HEXAGONAL CRYSTALS; CstiJne?
(293).
9. ETHER YIELDS, AFTER AGITATION, AN OILY OR FATTY
RESIDUE; Fatty matter (295).
10. MILKY APPERANCE; (Ihylous matter (296).
SECTION II.
Eyxamination of Urine 6ontaining no Solid Deposit; or from
which a Deposit has been separated (281).
300. Test the urine with litmus and turmeric paper
(277).*  If ALKALINE, it must be tested for ALBUMEN
with nitric acid (305, 306).
301. Take the specific gravity (279).t If the SPECIFIC
GRAVITY IS HIGHER THAN 1025, the urine may perhaps
be found to contain either SUGAR or an EXCESS OF UREA
(302, 304). If the specific gravity is not higher than
1025, pass on to 305. See also 304.
302. Whether UREA be present in excess, may be ascertained by mixing a little of the urine in a watch-glass,
with an equal bulk of pure nitric acid, keeping the glass
cool by allowing it to float in cold water. If any excess
of urea is present, a more or less abundant crop of crysIf these experiments had been already made before the separation of the sedimentary and non-sedimentary portions of the urine
(281), they need not be repeated. When the alkalinity is due to
amnionia or carbonate of ammonia, red litmus paper, which has been
rendered blue by it, will regain its color when dried by a gentle heat.
t See above note.




MORBID URINE.                  129
tals of nitrate of urea will, in a short time, appear in the
mixture (181). (Confirm 183.)
303. When a microscope is at hand, we can in this
manner detect even a very slight excess of urea. A drop
of the suspected urine is placed on a slip of glass, and
Ynix-ed with a drop of pure nitric acid. If even a small
excess of urea is present, minute crystals of the nitrate
may generally be seen after a short time, with a very
moderate magnifying power.
30-. To prove the presence of SUGAR, a little of the
urine may be examined by paragraphs 122 and 126.
(Confirm 113.) It must here be borne in mind, that very
decided traces of sugar may exist in urine without raising
the density to a suspicious extent, so that the mere circumstance of the specific gravity of the urine being below
1025 is no proof whatever of the absence of sugar; and
in any doubtful case it should be carefully looked for by
means of the tests above referred to.
305. Boil a little of the urine in a test-tube. If the
liquid remains clear, pass on to 307; but if a PRECIPITATE
IS PRODUCED, it may be owing to the presence either of
albumen (235), or of an excess of earthy phosphates (109),
To distinguish between them, add to the boiled portion
a few drops of nitric acid. If the PRECIPITATE DISSOLVES,
and is not reprecipitated by the addition of a few more
drops of the acid, it probably consists of EARTHY PHOSPHATES (229) (confirm 228, 226); while if it either does
not dissolve, or after being dissolved by the first drop or
two of the acid, again precipitates when the liquid is
more strongly acidified, ALBUMEN is indicated (143).
(Confirm 137, 138.).306. It must be remembered that when the urine is
alkaline ALBUMEN may be present in it without being
coagulated by boiling (142). Such urine should therefore be tested for albumen by means of nitric acid (141).
307. Add to a little of the suspected urine a few drops
of nitric acid. If a PRECIPITATE IS PRODUCED, either
immediately or after a short time, none having been
occasioned by boiling (305), an EXCESS OF URIC ACID iS
probably present (190). (Confirm 23, 288.) If the urine
is alkaline, the precipitate thus occasioned may consist of




130              EXA~MINATION  OF
ALBUMEN, since that substance would not then be precipitated by boiling (306).
308. Evaporate a little of the urine on a water-bath, to
the consistence of a syrup, and add about half its bulk of
strong hydrochloric acid. If, after the lapse of a few
hours, tufts or branches of NEEDLE-SHAPED CRYSTALS are
visible, either to the naked eye or when examined under
the microscope, an excess of HIPPURIC ACID is probably
present (206). (Confirm 208, 209.)
309. If THE URINE IS HIGHLY COLORED, it iS probable,
either that it contains an excess of yellow coloring matter, or that blood, biliary matter, or purpurine is present.
To determine which of these it is310. Boil a little of the urine; if it contains BLOOD, the
albumen will COAGULATE, mixed with some of the coloring matter (243). (Confirm 240, 245.)
311. If an excess of YELLOW COLORING MATTER is present, the boiled urine, when mixed with a little hydrochloric acid, will assume a more or less decided RED COLOR
(215).
312. The presence of biliary matter may be proved by
Pettenkofer's and Ileller's tests (149, 151). (Confirm 152.)
313. If PURPURINE is present in solution, the urine
usually has a more or less decided pink color; and when
a little warm  aqueous solution of urate of amnmonia is
mixed with it, that salt precipitates as the liquid cools,
and carries with it nearly the whole of the purpurine,
which gives the precipitate a PINK COLOR. (221).  (Confirml 218, 220.)
314. The following table may be found useful for reference (294).
* It will be remembered that many vegetable coloring matters taken
into the stomach make their appearance in the urine, and might, by
a careless examination, be mistaken for blood, &c.




.MORBID URINE.                131
TABLE
For facilitating the Examination qf the clear liquidi tion of Urine, by
means of Tests.
1. SPECIFIC GRAVITY HIGHER THAN 1025; See 2 and 3.
2. CRYSTALS WITH NITRIC ACID; Excess of urea (302).
3. HEAT WITH SULPHATE OF COPPER AND POTASH; SUgar (301).
4. IF NEUTRAL OR FEEBLY ACID TO TEST-PAPER, see 5,
&C. IF ALKALINE, see 7.
5. PRECIPITATE FORMED ON BOILING; SOLUBLE IN NITRIC ACID; EJxcess of earthy phosphates (305).
6. PRECIPITATE FORMED ON BOILING: INSOLUBLE IN
NITRIC ACID; Albumen (305).
7. PRECIPITATE FORMED BY NITRIC ACID; E.xcess of Uric
acid or albumen (307).
8. CONCENTRATED URINE YIELDS NEEDLE-BSHAPED CRYSTALS WITH HYDROCHLORIC ACID; HIippuric acid
(308).
9. IF THE URINE IS HIGHLY COLORED, see 10, 11, 12,
and 13.
10. DARK COAGULUM FORMED ON BOILING, Blood? (310).
11. RED COLOR WITH HYDROCHLORIC ACID; Excess of
coloring matter (311).
12 PINRK PRECIPITATE WITH WARM SOLUTION OF URATE
OF AMMONIA;-Purpurine (318).
13. CHANGE OF COLOR WITH NITRIC ACID, &c.; Biliary
matter (152, 312).
SECTION III.
Microscopic Examination of Urinary Deposits (276, 289).
315. Place a drop of the urine containing the deposit —
after being allowed to stand a short time, that the sediment may subside-on a strip of glass; cover it with a




132        MICROSCOPIC EXAMINATION
small square of thin glass,* and examine it with a magnifying power of about two hundred diameters. Observe
whether the particles are CRYSTALLINE, AMORPHOUS, or
ORGANIZED. If CRYSTALLB-, refer to paragraph 316; if
AMORPHO US, to paragraph 321; and if ORGANIZED, pass on
to paragraph 327. When, as is frequently the case, the
deposit appears to consist of a mixture of two or more
different forms of matter, each of these should in succession be examined, until the nature of the whole of the
deposit is clearly understood.
316. IF THE DEPOSIT IS CRYSTALLINE, it is probably
either URIC ACID, TRIPLE PHOSPHATE, or OXALATE OF
LIME; or possibly CYSTINE.
317. If the crystals are STELLATE (Fig. 41), or TRIANGULAR PRISMS (Fig. 42), instantly disappearing on the
addition of acetic acid, they consist of the TRIPLE PHOSPHATE.
318. IF THE CRYSTALS ARE LOZENGE SHAPEDI OR POSSESS ANY OF THE FORMS SHOWN IN FIGURE 43, being insoluble in dilute acids, but tolerably soluble in a solution
of potash, they are probably uric acid. (Confirm 288.)
319. If the crystals are OCTOHEDRA (Fig. 44), or some
modification of the DUMIB-BELL form (Fig. 45), insoluble
in acetic acid, but really soluble in dilute hydrochloric
acid, they are probably OXALATE OF LIME. (Confirm 287.)
320. If the crystals are MULTANGULAR PIRATES, having
the rosette-like form shown in Fig. 46, insoluble, or nearly
so, in water and dilute acids, but readily soluble in ammonia, the ammoniacal solution leaving, on evaporation,
HEXAGONAL CRYSTALLINE PLATES (Fig. 47), they are probably CYSTINE (172).
321. IF THE DEPOSIT IS AMORPHOUS, OR IN MINUTE,
ROUNDED PARTICLES, it probably consists of PHOSPHATE
OF LIME or URATE OF AMMONIA; or possibly URATE OF
SODA, FAT, or CHYLOUS MATTER. See also 327, &c.
322. If it is INSOLUBLE WHEN WARMED, BUT DISSOLVES
IMMEDIATELY on the addition of ACETIC OR DILUTE HEYDROCHLORIC ACID, it is probably PHOSPHATE OF LIMIE.
* Except for high powers, the thin glass may generally be dispensed
with.




OF MORBID  URINE.                  133
Fig. 41.                     Fig. 43.
Fig. 42.             4_;
Fig. 44.                     Fig. 45.
12
12~~~~~6  




134        MICROSCOPIC EXAMINATION
Fig. 46.                 Fig. 47.
co
323. If it DISSOLVES READILY when the urine containing it IS WARMED, and is again DEPOSITED ON COOLING, it
is probably URATE OF SODA OR AMMONIA.
324. If the deposit is in the form of PALE YELLOWISH
GRAINS, with or without small irregular protuberances
(Fig. 48), DISSOLVING more or less readily WHEN WARMED,
it is probably URATE OF SODA.
325. If the substance is in the form of MINUTE ROUND
GLOBULES, WITH DARK AND WELL-DEFINED OUTLINES
(Fig. 49), and DISSOLVES WHEN AGITATED with ether, it
probably consists of FATTY MATTER. (Confirm 295.)
326. If the urine is OPAQUE AND MILKY in appearance,
yielding fatty matter when agitated with ether, and containing minute amorphous, albuminous particles, and
perhaps also colorless globules, it probably contains
CHYLOUS MATTER. (Confirm 296.)
827. IF THE DEPOSIT CONSISTS OF ORGANIZED PARTICLES, it probably consists either of Mucus (which is
usually mixed with more or less EPITHELIUM), PUS, BLOOD,
or SEMEN. See also paragraph 132.
328. If the PARTICLES ARE ROUND, OR NEARLY SO,
AND GRANULATED on the surface, ENTANGLED in TENACIOUS, STRINGY MASSES, which do not break up and mix
uniformly with the liquid on agitation, it is probably
Mucus (Fig. 50, a). EPITHELIAL DEBRIS may be recognized by the peculiar forms of its particles (Fig. 50, b).
(156.) Mucous urine very generally contains also a considerable amount of earthy phosphates and other matters.
329. If the particles are ROUND AND GRANULAR (Fig.
51), not being held together by any tenacious matter, but
FLOATING FREELY IN THE LIQUID, the deposit probably
consists of PUS. (Confirm 290, 156.)




OF MORBID URINE.                 135
330. If the particles appear as CIRCULAR AND SLIGHTLY
CONCAVE DISKS, the outlines being occasionally irregular
(Fig. 52), and of a more or less decided yellowish color,
it is probable that BLOOD is present. (Confirm 292.)
331. If the particles, or any atnong them, have the
form of seminal animalcules, or SPERMATOZOA, shown in
Fig. 53, SEMEN is probably present.
332. The table on page 104 may be useful to the student for reference, in the microscopical examination of
urinary deposits.
Fig. 48.                  Fig. 49.
Fig. 50.
Fig. 51.
Fig. 52.                      Fig. 53.
-h    j~~~~~~~~~~~a~~~~i  X           \~~~~~~~~1




136     MICROSCOPIC EXAMINATION, ETC.
TABLE
Forfacilitating the Microscopical Examination of Urinary Deposits.
1. IF THE DEPOSIT IS CRYSTALLINE, see 4 to 7.
2. IF AMORPHOUS, OR ROUNDED PARTICLES, see 8 to 11
8. IF ORGANIZED PARTICLES, see 12 to 16.
Crystalline.
4. LOZENGE-SHAPED  CRYSTALS, AND OTHER  FORMS
SHOWN in Figure 43; Uric acid (318).
5. STELLJE, OR THREE-SIDED PRISMS (Figs. 41 and
42);  f4i2le phosphate (317).
6. OCTOHEDRA, OR DUMB-BELLS (Figs. 44 and 45);
Oxalate of lime.
7. ROSETTE-LIKE TABLES (Fig. 46); Cystine (320).
Amorphous or Rounded Particles.
8. SOLUBLE WHEN WARMED; Urate of soda or ammowia (91, 92, 96).
9. SOLUBLE IN ACETIC ACID; Phosphate of lime.
10. ROUND GLOBULES WITH DARK EDGES (Fig. 49);
Fatty matter (325).
11. WHITE AND MILKY; Chylous matter? (326).
Organized Particles.
12. GRANULATED CORPUSCLES, IN STRINGY AGGREGATIONS (Fig. 50); Mucus (328).
13. IRREGULARLY-SHAPED SCALES (Fig. 50, b); Epithelium.
14. DETACHED  GRANULATED  CORPUSCLES (Fig. 51);
Pus (329).
15. BLOODl-CORPUSCLES (Fig. 52); Blood (330).
16. SPERMATOZOA (Fig. 53); Semen.




QUANTITATIVE ANALYSIS, ETC.            137
CHAPTER VIT.
QUANTITATIVE ANALYSIS OF DIABETIC URINE.
333. IN the quantitative examination of diabetic urine,
it is generally sufficient to estimate merely the quantity
of sugar, since the determination of the other constituents is of comparatively small practical importance in
diagnosis. When this is the case, all- that is necessary
is, to ferment 250 grs. of the urine in the manner described below (336); and from the amount of carbonic
acid evolved, to estimate the quantity of sugar which
yielded it.
334. It is, however, frequently of importance to be
able to determine the proportion of some of the other
matters coexisting in the urine, especially the urea (119),
which has been supposed by some to diminish, and by
others to increase, materially in quantity, simultaneously
with the appearance of sugar. The exact estimation of
small quantities of urea, when mixed, as in diabetic
urine, with a large amount of sugar, is attended with
considerable practical difficulty; and, indeed, the results
hitherto obtained must be regarded merely as approximations to the truth. By the method of' analysis which
I am about to describe, the proportions of the following
substances may, without much difficulty, be determined,
or the inquiry may be limited to the estimation of the
sugar and the urea (335, 341): 1, water; 2, sugar;
3, urea; 4, uric acid and vesical mucus; 5, animal extractive and ammoniacal salts; 6, fixed alkaline salts;
and 7, earthy salts.
335. Two portions of the urine, A weighing 1000 grs.,
and B weighing 500 grs., are to be evaporated to dryness (50), in weighed or counterpoised dishes, on a water
or chloride of calcium bath; or, still better, in vactuo,
over sulphuric acid. While the evaporation of A and B
12*




138        QUANTITATIVE ANALYSIS OF
is going on, a third portion, C, consisting of 250 grs. of
the urine, may be weighed out, for the purpose of estimating the sugar, which is done in the following manner
(336).
336. Treatment of the portion C.* —Put 250 grs. of the
urine into a small wide-mouthed
Fig. 54.     bottle, capable of holding an ounce
and a half or two ounces of water;
to the mouth of which is adapted a
cork, fitted with tubes of the form
shown in the figure (Fig. 54). The
bottle should be graduated in cubic
inches and tenths, in order to enable
the experimenter to estimate the
amount of carbonic acid which is
retained in solution by the liquid at
the close of the operation (338). The
table a is nearly filled with small fragments of dry chloride
of calcium, which are prevented from falling out by a
loose plug of cotton wool placed at each end. The tube,
b, which reaches nearly to the bottom, is made open at
both ends; the top, however, being accurately closed by
means of a small bit of cork or wax, c, during the process of fermentation.
337. Mix a few drops of fresh yeast, or, still better,
about fifty grains of dry German yeast (128), with the
urine in the bottle; and having placed the cork, with its
tubes, firmly in the neck, weigh the whole apparatus,
with its contents, as accurately as possible. Allow the
apparatus to stand a day or two in a warm place, having
a temperature of about 70~ or 80~; and when the fermentation appears to have entirely ceased, remove the
small plug of cork or wax from the tube b, and suck air
gently from a, for the purpose of expelling the carbonic
acid contained in the bottle, and replacing it with cornmmon air. The small plug is then attached to the tube b,
as before, and the whole apparatus is again weighed.
338. The amount of loss will indicate the quantity of
* Although this method will furnish only a rough estimate of the
sugar present, the experiment is an instructive one for the student.




DIABETIC  URINE.                 139
carbonic acid which has escaped through the tube a; but
as carbonic acid is soluble, at ordinary temperatures, in
about its own bulk of water, the portion of acid held in
solution by the liquid must be added to that which has
escaped.  This amount is readily known, since each
cubic inch of liquid, which may be supposed to be saturated with the acid, must contain about a cubic inch of
the gas, weighing rather less than half a grain.*
339. The whole amount of carbonic acid formed during
fermentation, therefore, is determined by adding to the
loss of weight half a grain for every cubic inch of liquid
contained in the bottle; the quantity of which is known
by the graduations on the surface (336). Thus supposing the loss of weight during fermentation to have been
4-1 grs., and the volume of liquid in the bottle 1'2 cubic
inch, the weight of the carbonic acid formed must be 4:1
+'22, or 4'7 grains.
840. Now, since every equivalent of diabetic sugar
(C,2,H,,404) is converted, during fermentation, into two
equivalents of alcohol (C 4H0,IIO),  four equivalents
of carbonic acid (C,02), and two equivalents of water
(Ho);tC,,H 40,4=2( C4,H, 0,rO) +4C 02+4110;
it follows that every 198 parts by weight of sugar (one
equivalent) give rise to the formation of 88 parts of carbonic acid (four equivalents); so that every 88 grs. of
carbonic acid would indicate 198 grs. of sugar, or, in other
words, one gr. of carbonic acid will represent 2'25 grs.
of sugar. Therefore, by multiplying the weight of carbonic acid by 2 25, we obtain the weight of SUGAR present
in the quantity of urine operated on. Thus, in the above
example, 4-7 grs. multiplied by 2'25 (=10'57) gives the
weight of sugar in 250 grs. of urine; which, when multiplied by four (250 x 4= 1000), represents the proportion
in 1000 grs. of the secretion.
341. Treatment of the portion A.-The dry residue left
after the evaporation of the 1000 grs. marked A (335), is
* One hundred cubic inchles of carbonic acid weigh 47'30 grains;
one cubic inch, consequently, weighs 0'47 of a grain.
t See note to 129.




140         QUANTITATIVE ANALYSIS OF
to be used for estimating the urea, which is usually present only in minute proportion in diabetic urine. For
this purpose, the residue is treated with successive small
quantities of alcohol, stirring the mixture with a glass
rod, until it ceases to dissolve anything more.  The
alcoholic solution is now to be evaporated to dryness on
a water bath, and the residue treated with strong alcohol
(absolute alcohol, if possible, 114), which will dissolve
out the urea, leaving undissolved most of the sugar and
other matters. The alcoholic solution thus obtained is
to be again evaporated to dryness on a water bath, and
the residue treated, as long as anything dissolves, with
warm distilled water, which will separate the urea from
most of the other ma'tters which are less soluble in water.
342. The impure aqueous solution of urea thus obtained
is evaporated to a small bulk, and while at a temperature
of about 190~ or 200~, mixed with as much pounded
oxalic acid (HO,CO3+2Aq) as will dissolve in the liquid
(14).  The mixture, after cooling, is immersed in a
freezing mixture,* when the whole of the oxalate of urea,
together with the excess of oxalic acid, will crystallize
out. The liquid is now to be poured off, and the crystals
further treated as in 55.
343. Treatment of the portion B.-The residue left after
the evaporation of' the 500 grs. of urine marked B, may
now be examined, for the purpose of estimating, 1, the
water; 2, uric acid and vesical mucus; 3, animal extractive and ammoniacal salts; 4, fixed alkaline salts; and 5,
earthy salts. For this purpose it is to be carefully evaporated until it ceases to lose weight, either on a water or
chloride of calcium bath, or, still better, in vacuo over
sulphuric acid; since by long exposure to a high temparature a portion of the sugar loses five equivalents of
water, and becomes converted into a kind of uncrystallizable caramel, thus causing the residue to weigh less
than it ought to do. It is generally a matter of consi(lerable difficulty to expel the last traces of water from
* A little pounded ice or snow, mixed with about half its weight
of common salt; or in the absence of ice, a mixture of equal weights
of nitrate of ammonia and water, will be found the most convenient
freezing mixture.




DIABETIC URINE.         1       41
the residue of diabetic urine; for the ordinary purposes,
however, this is not of much importance, since.the small
error which it here occasions affects only the proportion
of the water and animal extractive, and not that of the
two substances of most importance-viz., the sugar and
the urea.
344. The dry residue B is to be weighed; and by
deducting its weight from that of the urine before evaporation (500 grs.), the proportion of water is determined;
which, when multiplied by two (500x2=1000), gives
the proportion of WATER in 1000 grs. of the secretion.
345. The weight of the dry residue having been carefully noted, it is to be treated with water as long as anything appears to dissolve. In this way the sugar, urea,
animal extractive, and alkaline salts are dissolved out,
leaving a small insoluble residue, consisting of vesical
mucus, uric acid, earthy phosphates, and traces of silica.
346. The aqueous solution thus formed is to be evaporated to dryness on a water-bath, and retained for subsequent experiments (349).
847. The weight of the matter insoluble in water (345),
having been noted after careful drying, it is to be incinerated until the residue becomes white or pale gray. The
ash thus obtained is to be weighed; and its weight,
multiplied by two, furnishes the proportion of EARTHY
SALTS in 1000 grains of the urine.
348. The difference between the weight of the ash and
that of the dry insoluble residue previous to ignition
(347), represents the quantity of insoluble organic matter,
consisting of URIC ACID and Mucus, in 500 grains of the
urine; which must be multiplied by two, as in the former
cases, in order to give the proportion of 1000 grains of
the secretion.
349. The dry residue obtained by evaporating the
aqueous solution (346), consisting of the soluble matters
of the urine, is now to be weighed. It consists of two
portions, the organic or combustible, and the inorganic
or incombustible. The relative amounts of these two
portions are determined by incineration; the weight of
the ash representing the FIXED ALKALINE SALTS in 500
grains; which, as before, is to be multiplied by two.




142        QITANTITATIVE ANALYSIS OF
350. The loss of weight experienced during incineration (349), which is that of the soluble combustible matters, viz., sugar, urea, animal extractive, and ammloniacal
salts, is also to be multiplied by two. Now, since we
know from our experiments with the other portions of
urine A and C, the weight of the sugar and urea (340,
342), we can, by deducting their combined weights from
the amount of loss during ignition, obtain the proportion
of ANIMAL EXTRACTIVE and AMMON1ACAL SALTS contained
in 1000 grains of the urine.
351. Thus we shall have determined the proportions
of the several ingredients of the urine, which together
should amount to a fraction less than 1000, viz:Water
Sugar
Urea
Uric acid and mucus.
Animal extract and ammoniacal salt
Fixed alkaline salts
Earthy salts
Loss.....
1000-00
352. One of the best methods of estimating the sugar
is founded upon its property of reducing the oxide of
copper (CuQ), in an alkaline solution, to the state of suboxide (CuaO), one equivalent of grape-sugar (C,,A,4014)
effecting the reduction of ten equivalents of the oxide.
To prepare the alkaline solution of oxide of copper,
advantage is taken of the circu mstances that the presence
of tartaric acid or a tartarate, enables the fixed alkalies
to retain the oxide in solution; and if there be a sufficiently large excess of caustic alkali present, the solution
may be boiled without alteration.
315'16 grs. of crystallized sulphate of copper are dissolved in about four ounces of water, and 1420 grs. of
the tartrate of potash and soda* (Rochelle salts, KO,NaO,
CsH40,,+8Aq) are powdered, andi added gradually to
* 950 grs. of pure cream of tartar (bitartrate of potash, KO,HO,
C8H,40,0) might be substituted for the Rochelle salts, but the latter is
preferable, as being more easily obtained in a pure state.




DIABETIC  URINE.                  143
the solution.  489 grs. of carbonate of potash are then
added, and 81 fluidounces of a solution of hydrate of
soda (caustic soda) of sp. gr. 1'12. The volume of the
mixture is made up to 10,000 grs. by adding water, the
whole boiled for a few minutes, and, if necessary, filtered.
1000 grain-measures of this solution should correspond
to 5 grs. of grape-sugar (C02TH1404).
In order to ascertain its exact strength, 4-32 grs. of
pure cane-sugar* (white sugar-candy, C121O11011) are dissolved in a little water, in a flask, a few drops of dilute
sulphuric acid added, and the mixture boiled for an hour
(replacing the water as it evaporates), in order to convert
the cane-sugar into grape-sugar. The solution is then
rendered slightly alkaline with carbonate of soda, and
its volume is made up to 1000 grs. with water. 500
grain-measures of the alkaline copper solution are heated
to boiling in a beaker or dish, and the solution of sugar
gradually added from a burette or graduated glass (Fig.
32), until the disappearance of the blue color, and the
non-occurrence of any fresh precipitate prove that the
whole of the oxide of copper has been reduced. If the
copper solution was correctly prepared, 500 grs. of the
sugar solution should have been required; but if more
or less than this have been found necessary, it is easy to
calculate the exact strength of the copper solution, which
should then be recorded upon the label of the bottle,
together.with the date of the experiment.  For example,
suppose 455 grs. of the. sugar solution to have completed
the reduction, then
Grs. of sugar-solution.  Grape-sugar.  Sugar-sol1ution used.
___   ___ J         A\-  )  __A.y_- 
1000:    5::       455: x
The value of x will represent the weight of grape-sugar
to which 500 grain-measures of the copper solution correspond. The solution must be kept in a well-stopped
bottle, which should be nearly filled by it, and set aside
in a dark place.
To determine the amount of sugar in diabetic urine.
W* hich will yield 5 grs. of grape-sugar. It would be better to
employ 5 grains of pure grape-sugar, but this is not so easily obtained.




144        QUANTITATIVE ANALYSIS OF
750 grain measures of. the urine are precipitated by a
solution of tribasic acetate of lead, added in very small
portions, with occasional stirring, as long as any fresh
precipitate is observed. The precipitate (phosphate, sulphate, and urate of lead, with extractive matters) is filtered
off, and washed with a little water, so as to make the total
volume of the filtrate and washings up to 1000 grs. 500
grain-measures of the alkaline copper solution are then
heated to boiling, and the purified urine added from a
burette, until the blue color of the solution has disappeared. A simple calculation will then give the amount
of sugar contained in the 750 grs. of urine originally
employed.
A very excellent method of controlling the result of
this experiment consists in adding to the solution from
which the blue color has disappeared enough of the alkaline copper solution to restore the blue color, boiling for
a few seconds, and collecting the precipitated suboxide
of copper upon a filter. It is then rapidly washed, as
long as the washings are alkaline, and dissolved by pouring over the filter a hot solution of perchloride of iron,
acidulated with hydrochloric acid, when the suboxide of
copper (Cu2O) is converted into the chloride (CuCI):
Cu2O + FeCI3 -+ HC1 = 2CuCl + 2FeCl = I-IO.
The filter is washed with much water, and the amount of
iron in the state of protochloride (FeC1) is determined by
adding a solution of permanganate of potash of known
strength* from  a burette, until a permanent faint rose
color is produced.
Now, each atom (198 parts) of grape sugar (C12H,1404)
precipitates five atoms (357 parts) of suboxide of copper
(Cu2O), and these, when dissolved in perchloride of iron,
produce ten atoms of protochloride of iron (FeCl), containing 280 parts of iron. Hence every grain of iron
indicated by the permanganate of potash represents 0-707
gr. of grape-sugar.
* The strength of this solution is readily determined by dissolving
5 grs. of pure iron wire in hydrochloric acid, diluting largely with
water, and adding the permanganate solution, from a burette, till the
permanent rose color is seen. About 1000 grs. of the solution should
be required for 5 grs. of iron.




DIABETIC  URINE.                      145
A slight error occurs in the determination of sugar in
urine according to this process, from the precipitation of
a little sugar by the tribasic acetate of lead; for although
a pure solution of sugar is not precipitated by that reagent, the precipitate which it causes in saccharine urine
is always accompanied by a little sugar.  In most cases
this error is too slight to be of any consequence, but its
extent may be easily ascertained by boiling the lead precipitate with oxalic acid, filtering, mixing the solution
with an excess of potash, and determining the sugar by
the alkaline copper solution. This will give a slight
error in the opposite direction, on account of the reduction of the oxide of copper by the uric acid.
The following analyses of diabetic urine will serve to
illustrate its usual composition in 1000 parts:Analyses I and Ir.  (Simon.)
1.       II.
Specific gravity.                  1018        1016
Water....  95700                    960'00
Solid constituents..   43'00                  40'00
Urea                            -  traces        7-99
Uric acid.                         traces      traces
Sugar....  39 80  25'00
Extractive matter and soluble salts.    2'10    6'50
Earthy phosphates.                   0'52      0'80
Albumen.                           traces      traces
Analyses III, I, and V. (Dr. Percy.)
IIT.     IV.        V.
S]pecifc gravity... 1042     1035      1039
Water.       894'50     918-30     898'90
Solid constituents.. 105'50      81s70     101'10
Urea...  12'16       30'32      2-39
Uric acid...   0-16        0-26  not isolated
Sugar...         40-12      17-15      79'10
Extractive matters and |  53'06     32-59      19'52
soluble salts. 
Earthy phosphates..             130        0'09
Analyses VI. (Bouchardat. )
Water.... 37-58
Solid constituents.... 16242
Urea...   8-27
Uric acid. -. not isolated
Sugar........134-42
Extractive matters and soluble salts         20'34
Earthy phosphates..                    038
18




146         QUANTITATIVE ANALYSIS OF
CHAPTER VIII.
QUANTITATIVE ANALYSIS OF ALBUMINOUS URINE.
353. IN the quantitative analysis of albuminous urine,
it is usual to estimate the following ingredients; though
for many purposes it is sufficient merely to determine the
proportion of albumen, either with or without that of the
urea: 1, water; 2, urea; 3, albumen, with traces of uric
acid; 4, vesical mucus; 5, animal extractive and ammoniacal salts; 6, fixed alkaline salts; and 7, earthy
salts.
354. Treatment of the portion A.-Two portions of the
urine, marked respectively A and B, each weighing 500
grains, are to be evaporated to dryness on a water-bath.t
The portion A will serve for the estimation of the urea;
and the portion B for that of the other substances above
enumerated.
355. The residue left after the evaporation of A is
treated with hot alcohol, to dissolve out the urea. The
alcoholic solution is evaporated to dryness on a waterbath, and redissolved, as far as it is capable, in hot distilled water; the aqueous solution thus obtained is evaporated to a small bulk, and mixed with pounded oxalic
acid in the manner described in the analysis of diabetic
urine (342). The oxalate of urea is afterwards decomposed by means of carbonate of lime in the manner
already detailed; the weight of the urea obtained being
multiplied by two, in order to represent the proportion
of UREA in 1000 grains of the urine.:
* Or the uric acid may be estimated separately. See paragraph 363.
t If it is intended to estimate the uric acid separately, a third portion
of urine, weighing 1000 grs., will also be required (363).
[ A far more accurate result would, of course, be obtained by heating the urine (acidified, if necessary, with acetic acid) to coagulate
the albumen, and determining the urea in the filtered liquid according
to (182).




ALBUMINOUS URINE.                147
356. Treatment of the portion B.-The residue left after
the evaporation of B is now to be examined. When it
has ceased to lose weight by exposure on the water-bath,
the weight of the residue is to be noted; and the loss
which it has sustained during evaporation, multiplied by
two, will represent the amount of WATER in 100 grains
of urine.
357. The dry residue, when cold, is to be carefully
reduced to powder in a clean dry mortar, which should
be placed on a large sheet of white paper, in order to
catch any particles that may be projected out of the mortar
during the pounding. The powder is to be warmed with
distilled water, which will dissolve out the urea, animal
extractive, and soluble salts; leaving an insoluble residue
of coagulated albumen, uric acid, mucus, and earthy
salts. The mixture is then filtered. The solution thus
obtained we call M, and the insoluble matter N.
358. The solution M is to be evaporated to dryness on
a water-bath, and subsequently examined in the manner
described below (361). While the evaporation is going
on, the insoluble matter N may be operated on (359).
359. The insoluble matter N, consisting of albumen,
uric acid, mucus, and earthy salts, is to be carefully detached from the filter whilst still moist. It is then warmed
for a few seconds with a little dilute nitric acid (consisting of one part of strong acid, and about ten parts of
water), and well stirred with a glass rod, in order to
dissolve out the earthy phosphates. The insoluble portion is to be washed with a little warm water (360), and
the acid solution, together with the washings, then
evaporated to dryness on a water-bath. The dry residue
is weighed, incinerated, and weighed again; when the
weight of the incombustible matter, multiplied by two,
will represent the proportion of EARTHY PHOSPHATES in
1000 parts of the urine; while the loss which the mixture
sustained during the incineration, also multiplied by two,
will represent the amouut of VESICAL MUCUS.
360. The portion of N which proved insoluble in the
dilute nitric acid (359), consisting of albumen, with
probably a little uric acid, is to be dried on a water-bath,
and weighed. The weight, multiplied by two, will repre



148       QUANTITATIVE ANALYSIS OF
sent the proportion of ALBUMEN and URIC ACID in 1000
grains of the urine.
361. The evaporated residue left by the solution M
(358), containing the urea, animal extractive, and soluble
salts, must now be examined. After its weight has been
ascertained, the dry residue is to be gently ignited until
the incombustible matter becomes white or pale gray.
The ash thus obtained is then weighed; and its weight,
multiplied by two, will represent the proportion of FIXED
ALKALINE SALS in 1000 grains of the urine.*
362. The loss of weight which the residue sustained
during incineration (361) being due to the combustion
of the urea and animal extractive, and the volatilization
of the ammoniacal salts, derived from  500 grains of
urine; we obtain, by doubling it, the amount of those
substances contained in 100 grains. From this we deduct
the proportion of urea, which we have already ascertained (355), and the difference will represent the amount
of ANIMAL EXTRACTIVE and AMMONIACAL SALTS contained
in 1000 grains of the secretion.
363. If it is required to estimate the proportion of uric
acid in albuminous urine, which, however, is seldom
necessary, since there is not often more than a small
trace of it present, a separate portion of urine must be
used for the experiment. For this purpose, 1000 grains
are to be boiled for about a quarter of an hour and
filtered from the coagulated albumen. The filtered liquid
is then concentrated to about one-fourth its bulk, by
evaporation on a water-bath, and after the addition of
a few drops of hydrochloric acid, set aside in a cool place
for forty-eight hours. The URIC ACID, if present in any
notable quantity, will gradually crystallize out, mixed
possibly with traces of hippuric acid (25), which may be
washed out with a little alcohol (28). The weight of the
residue will then, after drying on a water-bath, represent
the proportion of the acid in 1000 grains of urine.
364. Thus we shall have completed the analysis, having
determined the proportion of the several ingredients pro* During this ignition, traces of the alkaline chlorides are always
volatilized, causing a slight loss.




ALBUMINOUS URINE.                         149
posed; which, when added together, should amount to
a fraction less than 1000 grains, viz.Water
Urea
Albumen.
Uric acid
Vesical mucus
Animal extractive and ammoniacal salts.
Fixed alkaline salts
Earthy salts
Loss........
1000-00
365. The following analyses of albuminous urine, in
cases of Bright's disease, will serve to show its usual
composition in 1000 parts: —
Analyses I and II.  (Simon.)
I.       It.
Specific gravity. 1014       1022
Water....   96610  933'50
Solid constituents.                33 90      66-50
Urea....             477       10'10
Uric acid.....  040    0'60
Fixed salts.   804        10'00
Extractive matters...   240
Albumen.                        18.00      33'60
Analysis  L.  (Dr. Percy.)
Specific gravity.. 1020
-Water.946'82
Solid constituents.                           53'18
Urea.                                        7'68
Uric acid and indeterminate animal matter    17-52
Fixed soluble salts.                          520
Earthy phosphates.                            014
Albumen.......   22'64
13*




PART II.
CALCULI AND CONCRETIONS.
CHAPTER I.
URINARY CALCULI.
SECTION I.
366. URINARY calculi are composed, in the great majority of cases, of substances which are contained in
healthy urine, such as uric acid, urate of ammonia, and
the phosphates of lime and magnesia; they are, however,
occasionally composed of substances which are met with
only in morbid urine, such as oxalate of lime, cystine,
&c. Other substances also, which may strictly be called
accidental, are occasionally contained in calculi; such as
fragments of sand, or other hard bodies, which have
accidentally found their way into the kidneys or bladder,
and there formed nuclei, round which the earthy phosphates, or other matters, have gradually been deposited.
Calculi always contain, in addition to the ingredients of
which they mainly consist, more or less animal matter,
such as dried blood and urine, vesical mucus, &c.
867. Calculi are found to consist occasionally almost
entirely of one ingredient only, but more frequently of
two or more different constituents arranged together in
irregular concentric layers. On this account it is impossible to determine, with any degree of certainty, the
nature of the mass of calculus, by merely examining
the external coating, since the more central portion may
be of a nature wholly different. The best way is to




URINARY  CALCULI.                  151
divide the calculus into two equal parts, which is easily
done by carefully cutting it through the centre with a
fine saw. Fig. 55 represents a
mixed calculus divided in this           Fig. 55.
manner; the darker layers consisted, in the specimen  from
which the drawing was made,
of oxalate of lime, and the
lighterringsofuricacid. When
a calculus is thus found on examination to consist apparently
of two or more kinds of matter,
fragments of each kind should        Alternating Calculus.
be carefully detached and separately examined (411).*
SECTION IT.
Uric (or Lithic) Acid (C10,4N406).
368. Uric acid calculi are usually smooth or slightly
tuberculated on the surface (Fig. 56), -and of colors varying from pale yellowish fawn to reddish-brown. When
sawn through, the layers will
generally be found to be tolerably        Fig. 56.
regular, though of different thicknesses, and nearly parallel to the
outline of the section.  This is the
most common of all the urinary
calculi.
369. Heat a small fragment of
the calculus on platinum foil; it      Uric Acid Calculus.
immediately blackens, owing to
the charring of the animal matter, emitting, at the same
time, adisagreeable smell, resembling that of burnt feathers,
mixed with that of hydrocyanic acid (H,C2N), which,
together with carbonate of ammonia and some other
compounds, is formed during the decomposition. If the
heat be continued, the charcoal residue is gradually con* A small fragment of the calculus, about the size of a pin's head, is
generally sufficient for each experiment, and will be found more convenient in practice than a larger quantity.




152               URINARY- CALCULI.
sumed, leaving only a slight trace of ash, which is usually
alkaline to test-paper, consisting of phosphate or carbonate of soda. Traces of the earthy phosphates, also, are
almost always to be found in this and most other varieties
of calculi.
370. Uric acid is sparingly soluble in water, and in
cold dilute acids (22).
371. A little of the calculus in powder is placed in a
drop or two of tolerably strong nitric acid, in a watchglass, or on a strip of glass or platinum; it dissolves with
effervescence, carbonic acid and nitrogen being given off,
and a mixture of alloxan (CH14N20,o), alloxantine
(C8,H,N,O,,), and some other compounds, remains. This
is evaporated to dryness, at a gentle heat, when a red
residue is left, which when cold, and treated with a drop
of ammonia, or ex'posed to ammoniacal fumes, becomes
purple, owing to the formation of murexide (C,12H6NsO0).
872. Uric acid calculus dissolves in a dilute solution
of potash, leaving only a few shreds of animal matter
(366); and when the mixture is warmed, no smell of ammonia is perceptible, thus differing  from  the urate  of
ammonia (377). On neutralizing the alkaline solution
with any acid, as hydrochloric, a white precipitate of pure
uric acid  is- thrown down, which, when separated  by
filtration, may be tested with nitric acid and ammonia, as
described in 371.
373. If the precipitated uric acid be examined under
the microscope, it will be found to consist of minute
crystals, having the form shown in Fig. 3, page 32.*
* Xanthic or Uric Oxide or Xanthine (C,104N404), which composes a very rare form of calculus, also dissolves in potash, and is
reprecipitated by hydrochloric acid. When dissolved in nitric acid,
however, it leaves a yellow residue on evaporation, which is not
reddened by ammonia. Xanthic oxide has also been found in normal urine, and in the spleen, pancreas, brain, and liver of oxen and
other animals. Hypoxanthine (C,,H4N402) is very similar in its properties, and has also been found in the spleen. Dr. Bence Jones has
observed, in one case in the urine, a deposit which had the chemical
characters of xanthic oxide, and appeared, under the microscope, in
lozenge-shaped crystals, resembling some of the forms of uric acid.




URINARY CALCULI.-                153
SECTION III.
Urate (or Lithate) of Ammonia (NH,O,O, CjT2N404).
374. It is not often that we meet with calculi composed
wholly of urate of ammonia, that substance being more
commonly found alternating with uric acid, earthy phosphates, or other matters. These calculi are generally
small in size, smooth, or slightly tuberculated (Fig. 57).
and pale slate or clay color, sometimes inclining to brown. The          Fig. 57.
concentric layers are usually
thinner, and less distinctly marked, than those of uric acid.
875. When heated, urate of
ammonia usually decrepitates,
gradually disappears, and in
other respects behaves like uric
acid (369). It dissolves tolerably   Urate of Ammonia Calculus.
well in hot water; but being insoluble, or nearly so, in cold, is deposited again when the
solution cools, as an amorphous precipitate. If a dilute
acid, as hydrochloric, be added to a hot solution of urate
of ammonia, the latter is decomposed, and the uric acid
set free, which, being sparingly soluble even in hot water,
is precipitated in the form of minute crystals (Fig. 3, page
32).
376. With nitric acid and ammonia, urate of ammonia
produces the same results as uric acid (371).
377. Urate of ammonia dissolves readily in a warm
dilute solution of potash, giving off at the same time
ammoniacal fumes by which it may be distinguished from
uric acid and urate of soda. The addition of a dilute
acid to the hot solution causes a crystalline precipitate of
uric acid (373).
SECTION IV.
Phosphate of Lime (3CaO,PO).
378. Calculi of phosphate of lime are most commonly
smooth and even polished on the surface. The concentric




154             URINARY CALCULI.
Fig. 58.      larnine aregenerally arranged with
considerable regularity (Fig. 58);
and when the calculus is broken,
these separate from  each other
with great facility, forming de.
tached crusts. The color is usually
Phosphate of Lime Calculus.  fawn or stone color.
379. Before the blowpipe it
chars, owing to the presence of a
little animal matter, and gradually becomes white as the
carbonaceous matter burns away. It is almost infusible,
requiring for its fusion so intense and prolonged a heat,
that few can succeed in fusing it.
380. The residue, after ignition, is neutral to test-paper.
381. It is soluble, without effervescence, in dilute nitric
or hydrochloric acid (49).
382. To the solution in nitric acid formed in the last
experiment add ammonia in slight excess; the phosphate
of lime will be precipitated as a gelatinous precipitate.
Re-dissolve this in a little acetic acid, and divide the
solution in two parts.
383. To one part of the acetic solution add a drop of
perchloride of iron, which will cause a yellowish-white
precipitate of perphosphate of iron (Fe203,PO).
384. To the second part of the solution add oxalate of
ammonia, when the white precipitate of oxalate of lime
will be formed.
385. If a little of the powdered phosphate of lime be
mixed with about twice its bulk of the double phosphate
of ammonia and magnesia, or triple phosphate (MgO,N
E40, PHO,PO), and heated before the blowpipe on platinum
wire, it readily fuses. The fusible calculus is composed
of a similar mixture of the two salts (391).
SECTION V.
Phosphate of Ammonia and Magnesia, or Triple Phosphate
(MgO, NH40, HO, PO).
386. Calculi composed entirely of triple phosphate
are of somewhat rare occurrence; but mixed, or alternating with other matters, and indeed constituting the great




URINARY CALCULI.                155
bulk of the concretion, this substance is very common.
Such calculi are sometimes found to have been deposited
in concentric layers, and sometimes consist of an aggregated mass of prismatic crystals.  They are usually
nearly colorless, or slightly tinged with drab or stone
color. The surface is most commonly rough and uneven,
and often covered with small, shining crystals.
387. The triple phosphate calculus, when heated before,
the blowpipe, chars, and gives off the smell of ammonia;
swells up, gradually becomes gray as the carbonaceous
matter is consumed, and ultimately fuses.
388. It is almost insoluble in water, but if boiled, a
small quantity will be found to dissolve.
389. It dissolves readily in dilute hydrochloric and
most other acids, and is again thrown down in the form
of a crystalline precipitate, when the solution js neutralized with ammonia. If the precipitate thus obtained be
examined under the microscope, it will be found to consist of well defined crystals, which, if the solution has
been supersaturated with the ammonia, are stellate (Fig.
10, page 46); but if merely neutralized, they are pris.
matic (Fig. 8, page 45) (44).
390. When heated with a solution of potash, it is
decomposed, the potash combining with the phosphoric
acid, and setting free the ammonia and the magnesia.
The former volatilizes, and may be detected by the smell,
while the magnesia is precipitated (49).
MgO,NH40,1HO,PO5,+2KO=2KO,HO,PO5+ NH3+MgO,HO.
SECTION VI.
Fusible -Calculus, which is a mixture of Phosphate of Lime
(3CaO,PO,), and the Triple Phosphate (MgO,N1HO,HO,
PO5).
391. The fusible matter of which this form of calculus
is composed, is, next to uric acid, the most common of
the ingredients of calculi. It sometimes constitutes the
entire mass of the calculus; is also frequently found alternating with other ingredients; and very commonly forms
the outer crust of calculi composed of uric acid and other




156             URINARY CALCULI.
matters. Fusible calculi are generally oval or irregular in form (Fig. 59); white, soft, and
Fig. 59.    friable, resembling chalk; though occasionally they are compact and hard.
392. This calculus is chiefly characterized by the readiness with which
it fuses before the blowpipe, without being consumed; in which reFusible Calculus.   spect it differs from all other kinds
of calculus. During the ignition, the
ammonia and water are expelled, leaving a mixture of
the phosphates of lime and magnesia.
393. If a portion of the calculus be dissolved in dilute
hydrochloric acid, and ammonia added in slight excess,
the mixed phosphates are precipitated and may be recognized under the microscope (43).
394. If the precipitate be redissolved in acetic acid,
and the solution mixed with oxalate of ammonia, the
lime will be separated as oxalate, and if this be filtered,
off (after boiling), the phosphate of magnesia and ammonia may be obtained as a crystalline precipitate by adding
an excess of ammonia.
SECTION VII.
Oxalate of Lime Calculus (CaO,0,C03).
395. Calculi are not unfrequently met with, composed
almost entirely of oxalate of lime; but more commonly
the nucleus will be found to conFig. 60.     sist of uric acid or urate of lime.
Oxalate of lime calculi are usually;.,i~ g   J l    nvery dark in color, either brown or
dark olive, or a kind of dirty purple. Their surface is much more
irregular and rugged than that of
other descriptions of calculi; and
when sawn asunder, they exhibit
Oxalate of Lime Calculus
an irregular and angular structure,
as shown in Fig. 60. From their
resemblance to the fruit of the mulberry, this variety is
commonly known as the mulberry calculus.




URINARY CALCULI.                157
396. There is also another form in which oxalate of
lime calculi are occasionally met with, commonly called
hemp-seed calculi. These are small, round, or oval, and
very smooth and polished on the exterior; they generally
contain also a little urate of ammonia.
The general form and appearance of these oxalate of
lime calculi are usually so peculiar and characteristic,
that they may be in most cases, easily recognized by
simple inspection.
397. Powdered oxalate of lime dissolves without effervescence in dilute nitric and hydrochloric acids, and is
again thrown down unchanged, in the form of a white
precipitate, when the acid solution is neutralized with
ammonia; the precipitate is insoluble in acetic acid.
Occasionally a little carbonate of lime is found mixed
with the oxalate, in which case slight effervescence will,
of course, take place on the addition of the acid.
898. Oxalate of lime is insoluble in acetic and oxalic
acids.
899. When heated, it blackens, and gives off a disagreeable smell, resembling that of burnt feathers. If the
heat be continued a short time, the residue becomes
white, and then consists of carbonate of lime, into which
the oxalate is converted; carbonic acid being also, with
other gaseous matters, at the same time given off.
CaO,C  +0= CaO,C0- + CO,2.
400. Treat the residue formed in the last experiment,
with dilute hydrochloric acid: it readily dissolves, with
effervescence, showing that it has been changed into the
carbonate.
401. The solution of chloride of calcium (CaCl) thus
formed, may be neutralized with ammonia, and tested for
lime with oxalate of ammonia, which will throw down
the oxalate of lime (CaO,C0203+2Aq), in the form of a
white precipitate (171).
402. If the oxalate of lime be kept intensely heated
for some little time, the carbonate which is at first formed
is reduced to the state of caustic lime (CaO); which may
be proved by placing the residue, when cold, on a piece
14




158             URINARY CALCULI.
of moistened turmeric paper, the yellow color of which
will be turned to brown.
SECTION VIII.
Urate (or Lithate) of Lime (CaO,HO,C,,1oH2NO).
403. This substance, though never found composing
entire calculi, is not unfrequently present in small quantities in concretions which consist chiefly of uric acid,
oxalate of lime, or other matters.
40()1. Urate of lime is nearly insoluble in cold water,
but dissolves in hot, though somewhat less readily than
urate of ammonia (375). The hot aqueous solution deposits it again on cooling, generally in the form of minute
needle-shaped crystals.
405. Like the other urates, it is decomposed by hydrochloric acid. If the acid be added to a hot aqueous solution of the salt, a crystalline precipitate of uric acid-is
thrown down (377, 373), and chloride of calcium remains
in solution.
406. When tested with nitric acid and ammonia, in
the manner described in paragraph 371, urate of lime
behaves like uric acid and the other urates, yielding the
rich purple color of murexide.
407. As this is the only salt of lime found in calculi
which is soluble in hot water, it may be supposed to be
present when, after boiling a little of the powdered calculus in water, the hot aqueous solution gives a white
precipitate of oxalate oF lime (CaO,C203+2Aq), when
tested with oxalate of ammonia.
SECTION IX.
Cystine (C016NO4,S,)
408. Calculi of cystine are of rather rare occurrence.
They are usually more or less crystalline in structure,
not deposited in laminie, soft, and of a pale brownishyellow or greenish tint. Small calculi composed almost
exclusively of this substance have been occasionally
found in the dog.
409. The chemical characters of cystine, and the me



ANALYSIS OF CALCULI.              159
thods of distinguishing it by tests, will be found described
in the chapters on urine (172, 269, &c.).
410. The following directions will facilitate the identification of the several varieties of urinary calculi.
CIIAPTER IT.
CUALITATIVE EXAMINATION OF URINARY CALCULI, THE
COMPOSITION OF WHICH IS UNKNOWN.
411. WHEN a calculus has to be examined with a view
to ascertaining the nature of its ingredients, a very few
simple experiments, conducted on some such plan as the
following, will generally furnish the required information. The calculus should first be sawn through, and the
loose dust gently brushed away. If the several laminme
of which the mass is composed appear to be homogeneous, and to consist of the same kind of matter, a small
fragment may be taken from any part of it for examination (412); but if, as is more frequently the case, there
appear to be two or more different kinds of matter contained in the several layers (367), fragments of each of
them  should be carefully detached from the mass, and
examined separately in the following manner.
412. Place a small fragment on platinum foil, and heat
it to redness before the blowpipe, until the blackness of
the charred animal matter disappears. Observe whether(a) IT BURNS AWAY, LEAVING ONLY A MINUTE TRACE
OF ASH (413); or
(b) IT PROVES INCOMBUSTIBLE, WITHOUT MATERIALLY
LESSENING IN BULK (414); or
(c) IT IS PARTIALLY CONSUMED, leaving however, a
considerable residue of incombustible matter (415).
413. IF IT BURNS AWAY, leaving only a minute trace
of incombustible ash, it is probably either uric acid,
uratesof ammonia, or cystine; or possibly a mixture of
two or more of them. See 416-419.
414. IF IT IS INCOMBUSTIBLE, not materially lessening




160          ANALYSIS OF CALCULI.
in bulk during the ignition, it is probably either phosphate of lime, triple phosphate, fusible matter (391),
oxalate of lime (converted into carbonate by the heat),
urate of lime (also converted into carbonate); or, perhaps,
two or more of those substances mixed together. See
420-425.
415. IF THE FRAGMENT IS PARTIALLY CONSUMED, it will
probably be found to consist of a mixture of one or more
of the combustible substances mentioned in paragraph
413, with some of those enumerated in paragraph 414.
See 426-428.
Examination of combustible Calculi (413).
416. If the calculus (in powder) is found to be sparingly SOLUBLt IN WARM WATER; SOLUBLE IN DILUTE
SOLUTION OF POTASH, without the evolution of ammonia;
and to form, when tested with nitric acid and ammonia,
a PURPLE RESIDUE; it is probably URIC ACID (370, 372,
371). (Confirm 373.)
417. If it is found to be SOLUBLE IN HOT WATER;
SOLUBLE IN DILUTE SOLUTION OF POTASH, with the evolution of ammoniacal vapors; and to yield, with nitric
acid and ammonia, a PURPLE RESIDUE; it is probably
URATE OF AMMONIA (375, 377, 376). (Confirm 373.)
418. If it is found to be INSOLUBLE IN WARM WATER;
readily SOLUBLE IN AMMONIA; the ammoniacal solution
yielding, on slow evaporation, HEXAGONAL CRYSTALLINE
PLATES, it is probably CYSTINE (174, 173). (Confirm 174,
271, 273).
419. If it is suspected that more than one of the above
substances are present, a little of the powder may be
boiled with water, and if any portion remains undissolved, the mixture filtered while hot.
(a) If the clear filtered liquid DEPOSITS ON COOLING AN
AMORPHOUS PRECIPITATE, URATE OF AMMONIA is probably present (375). (Confirm 417.)
(b) If the insoluble portion gives a PURPLE COLOR
when tested with nitric acid and ammonia, URIC ACID is
probably present (371). (Confirm 416.)
(c) If the insoluble portion is wholly or partially




ANALYSIS OF CALCULI.              161
SOLUBLE INAMIMMONIA: the ammnoniacal solution,yielding
on evaporation, HEXAGONAL PLATES, CYSTINE is probably
present (173).*
Examination of Incombustible Calculi (414).
420. If the matter of the calculus is INFUSIBLE BEFORE
THE BLOWPIPE; SOLUBLE IN DILUTE HYDROCHLORIC ACID;
the acid solution of the substance after ignition, yielding,
when neutralized with ammonia, an AMORPHOUS PRECIPITATE, it is probably PHOSPHATE OF LIME (379, 381, 382).
(Confirm 383, 384.)
421. If it is TOLERABLY FUSIBLE, before the blowpipe;
SOLUBLE IN DILUTE HYDROCHLORIC ACID; the acid solution giving, when neutralized with ammonia, a CRYSTALLINE PRECIPITATE, it is probably TRIPLE PHOSPHATE
(387, 389). (Confirm 390.)
422. If it is readily FUSIBLE before the blowpipe;
SOLUBLE IN DILUTE HYDROCHLORIC ACID; the acid solution yielding, when supersatuated WITH AMMONIA, A
PRECIPITATE, which, when examined under the microscope, is found to contain both AMORPHOUS PARTICLES
and also CRYSTALLINE STELLrE, it is probably composed
of the MIXED OR FUSIBLE PHOSPHATES (392, 394).
423. If the substance, before ignition, is SOLUBLE WITHOUT EFFERVESCENCE, in dilute hydrochloric acid; the acid
solution yielding a WHITE PRECIPITATE WHEN NEUTRALIZED WITH AMMONIA: and after gentle ignition, is SOLUBLE
WITH EFFERVESCENCE in the dilute acid; the acid solution, moderately diluted, now yielding NO PRECIPITATE
when neutralized with ammonia, it is probably OXALATE
OF LIME (397, 400, 401). (Confirm 398, 402.)
424. If the hot aqueous solution, formed by boiling a
little of the powdered calculus with water, gives a WHITE
PRECIPITATE WITH OXALATE OF AMMONIA, the presence
of URATE OF LIME is indicated (407). (Confirm 401, 405,
406.)
* A very rare combustible calculus, discovered by Heller, is called
urostealith. It is soft and elastic when fresh, but becomes hard after
drying. When heated it evolves a resinous odor, somewhat similar
to that of benzoin. It is readily soluble in either, and sparingly in
alcohol.
14*




162          ANALYSIS OF CALCULI.
425. If it is suspected that more than one of the above
substances are present in the portion of the calculus
under examination, it may be gently ignited, and then
treated with dilute hydrochloric acid.
(a) IF EFFERVESCENCE ENSUES(the calculus before ignition, not causing effervescence with the acid), oxalate (or
possibly urate (c),) of lime is present (397, 400).
(b) Supersaturate the acid solution with ammonia; and
if any PRECIPITATE IS PRODUCED, examine it under the
microscope for PHOSPHATE OF LIME and TRIPLE PHOSPHATE (382, 389).
(c) Boil a little of the powdered calculus with water;
and test the hot aqueous solution thus obtained, with
oxalate of ammonia. If a WHITE PRECIPITATE iS produced URATE OF LIME is probably present (407). (Confirm 405.).Examination of Partially Combustible Calculi (415).
426. When the calculus, or any portion of it, is found
to be partially consumed when ignited, it is probably a
mixture of one or more of the combustible matters
enumerated in paragraph 413, associated with one or
more of the incombustible ingredients mentioned in
paragraph 414.
4z7. A portion of the calculus, before ignition, may
first be examined for the organic or combustible ingredients, in the manner described in paragraph 419, ac, b,
and c.
428. Another portion of the calculus may then be
gently ignitedl on platinum foil, and the residue examined
for the inorganic matters, according to the directions
given in paragraph 425, a, b, and c.




BILIARY  CALCULI OR GALL-STONES.    163
CHAPTER III.
BILIARY CALCULI OR GALL-STONES.
429. BILTARY calculi are usually of a pale yellow or
brownish color; soft, soapy to the touch, and easily
crushed into small fragments by pressure; and the texture of the mass is in most cases decidedly crystalline.
The size most commonly met with is
about that of a pea; but they are frequently   Fig. 6l.
found much smaller, and occasionally
almost as large as a pigeon's egg.  The
form  is generally irregular and some-  a
what angular, as shown in Fig. 61.
430. They usually contain from  fifty
to eighty per cent. of cholesterin (CH,44   Biliary Calculi.
0,); the rest of the concretion being
made up of biliary resin and coloring matter, mucus,
and traces of other animal matters,* with a small quantity
of inorganic salts.  The percentage composition of three
specimens analyzed by Brande was as follows:I.      II.    III.
Cholesterin.. 81-25   69-76   81-77
Biliary resin.. 3 12    5-66    3-83
Bile-pigment.... 9-38   11 38    7'57
AlbumLen and salts extractable
by water.... --   -----    3.83
Biliary mucus.... 6'25   13'20  -
431. Heat a small fragment of gall-stone on platinum
foil; it will fuse and burn with a bright but smoky flame,
leaving a small fixed residue, consisting of inorganic salts.
432. When coarsely powdered, it dissolves readily in
boiling-alcohol; and on cooling, the cholesterin crystalizes out in the form  of fine scaly crystals.  (Fig. 62),
* Among which stearate and palmitate of lime have been noticed.




164           GOUTY CONCRETIONS.
while the biliary resinous and coloring matters remain
in solution, giving the liquid a yellowish tinge.
433. It is insoluble in dilute nitric and hydrochloric
acids. It is insoluble also in a solution of potash; thus
diftfering from other fatty
Fig. 62.          and   oily  substances,
_~     which  cholesterin  resembles in many parts.
= ==~~~~~~ S;,_Cholesterin is found in
_,  -       E  large  quantity  in  the
fluid in ovarian dropsy,
and in hydrocele.
___~_  ~434. For a more com______            =_plete analysis of biliary
Cholesterin.       calculi, Dr. Thudichumn
recommends the following process: The powdered calculus is digested with hot
benzole, which dissolves the cholesterin. The residue,
having been washed with alcohol, and dried, is treated with
ether and a little nitric acid, by which the fatty acids are
removed. On washing the residue on the filter with
water, phosphates and nitrates of lime and magnesia are
extracted (with occasionally a little copper). The final
residue consists of biliary coloring matter, and a small
quantity of earthy salts.
CHAPTER IV.
GOUTY CONCRETIONS.
435. THESE earthy concretions, which form in the joints
of gouty persons, are usually white, or nearly so, soft
and friable, closely resembling chalk in appearance, and
hence commonly known as chalk stones. They seem to
vary a good deal in composition; but in the great majority
of those which have been analyzed, acid urate of soda
* Chem. Soec. Quar. Journ., July, 1861.




GOUTY CONCRETIONS.               165
(NaO,HO,OCH2N404) appears to form the principal and
most characteristic ingredient. They contain also a considerable quantity of chloride of sodium and dried cell ular
tissue; with occasionally urate of lime (CaO,HO,C1,,H2N4
04), phosphate of lime (3CaO,P05), and chloride of potassium. The presence of a large quantity of uric acid
may be shown by the formation of the purple-colored
murexide, when a little of the concretion, in powder, is
treated with nitric acid and ammonia, in the manner
described in paragraph 371.
Qualitative Examination of Gouty Concretions.
436. Reduce the concretion intended for analysis to
tolerably fine powder, and digest it in cold water to
dissolve out the chlorides of sodium and potassium.
Filter the solution from the insoluble portion, which
must be reserved for subsequent examination (440).
437. Test a few drops of the aqueous solution thus
formed with nitrate of silver. A white curdy precipitate,
which is readily soluble in ammonia, but insoluble in
nitric acid, will show the presence of CHLORINE (chloride
of potassium or sodium) (41, a).
438. Mix the rest of the aqueous solution with bichloride of platinum; evaporate the mixture to dryness, or
nearly so, on a water-bath; and observe the yellow,
needle-shaped crystals of the double chloride of sodium
and platinum  (NaCl,PtCl2), showing the presence of
SODIUM (chloride of sodium).
439. Add a little alcohol to the evaporated residue.
and observe whether any small, yellow, sandy-looking
crystals remain undissolved, indicating the presence of
POTASSIUM (41, e).
440. The portion which proved insoluble in cold water
(436), may now be treated with hot water, and gently
boiled with successive small quantities of the liquid as
anything appears to dissolve. The urate of soda is thus
slowly dissolved, together with any urate of lime that
may be present (97, 404). The matter which proves
insoluble in the hot water is to be retained for subsequent
examination (444).




166            GOUTY CONCRETIONS.
441. Hydrochloric acid is now added in slight excess
to the hot aqueous solution, and the mixture set aside
until it cools, in order to allow the uric acid, which will
have been displaced from the soda and lime by the hydrochloric acid (405), to separate completely from the sol ution.
The uric acid is thus precipitated; leaving in solution
chloride of sodium, and also, in case any urate of lime
was present in the concretion, a little chloride of calcium.
442. The mixture thus obtained is filtered. The uRtc
ACID may be examined with the micioscope and with
other tests (373, 371); and a little of the aqueous solution
may be neutralized with ammonia, and tested for LIME
with oxalate of ammonia (171).
443. The rest of the aqueous solution may be evaporated at a gentle heat with bichloride of platin um; when
the yellow needles of the double chloride of sodium and
platinum will prove the presence of a large quantity of
SODA derived from the urate (435).
444. The remaining portion of the concretion, which
resisted the action of the hot water (440) may now be
examined. It will probably be found to consist chiefly
of dried cellular matter, with perhaps a little phosphate
of lime (435). The animal matter may be burnt away,
by keeping it at a red heat until the blackness disappears;
after which the incombustible residue may be examined
in the manner described in paragraph 425, and will probably be found to consist of phosphate of lime.
445. The following is an analysis by T. J. Herapath of
some concretions taken from the joints of the fingers of
a man suffering from gout:Fat  1123
Chloride of sodium
Phosphate of soda                    traces.
Extractive matter
Albumen
Urate of soda, with some urate of potash  43-973
Urate of litne....                14769
Phosphate of lime....       34-141
Perphosphate of iron....  traces.
Water and loss  5994
100-000




SOLID EXCREMENTS.                 167
CHAPTER V.
SOLID EX;CREMENTS,
445a. THE separation of the proximate principles contained in the solid excrements is effected by Dr. Marcet,
by the following process:The feces are exhausted by boiling alcohol, and rapidly
strained through a cloth. The alcoholic solution, on
standing for a short time, yields a deposit which is partly
dissolved by boiling alcohol; the insoluble portion of
this deposit is boiled with potash, which dissolves it
almost entirely, and the alkaline solution neutralized
with hydrochloric acid, gives a deposit of mcargaric acid,
whilst the acid filtrate, neutralized by ammonia, yields a
precipitate of phosphate of lime.
The alcoholic solution, after longer standing, deposits
some margarate of mcagnesia, and if exposed to cold for
some hours, it gives crystals of excretine.
If the solution obtained by boiling the first deposit
with alcohol be evaporated to dryness, the residue extracted with ether, and the ethereal solution heated with
alcohol and lime-water, a precipitate is formed which
when treated with hydrochloric acid and ether, yields,
on evaporating the ethereal solution, an olive-colored
substance named excretolic acid.
If the alcoholic liquid containing the excretine (or from
which the excretine has been separated by cooling) be
mixed with lime, a yellowish-brown deposit is formed,
which yields exeretine to boiling ether. If the portion
left undissolved by ether be treated with alcohol and
hydrocloric acid, it gives a port-wine colored solution,
which deposits margaric acid on standing. If water be
then added, and the solution concentrated by evaporation,
a brown substance separates, which may be purified by




168               SOLID  EXCREMENTS.
solution in either and washing with water. It then much
resembles the coloring matter of blood and that extracted
by Dr. Harley from urine (36).
Excretine (C78H7802S).  This new proximate principle
crystallizes in four-sided prisms, which are insoluble in
water, and sparingly soluble in cold alcohol, but dissolve
readily in ether. Its solution has a feeble alkaline reaction. It fuses a little below 212~, and is not dissolved
by boiling with solution of potash.
Excretolic acid, the composition of which has not yet
been determined, is a very fusible olive-colored body,
which is insoluble in water and in boiling potash, dissolves sparingly in cold alcohol, but readily on heating,
and is very soluble in ether. Its solutions have a marked
acid reaction.
As far as they  have yet been  examined, healthy
human excrements contain —
Excretine.*
Excretolic acid.
Peculiar red coloring matter.
Margarates of lime and magnesia.
Butyric acid.
Taurine.
Phosphate of lime.
Phosphate of magnesia and ammonia.
Phosphate of potash.
Insoluble and undigested matters derived from the food.
D* r. Marcet estimates the average amount of excretine in each
evacuation at about 2'8 grs. In the feces of an infant cholesterine
was found, but no excretine. The feces of a man with a diseased
pancreas contained a large portion of bistearate of soda.




P ART III.
BLOOD.
CHAPTER  I.
HEALTHY BLOOD.
SECTION I.
General Characters of Blood.
446. THE general appearance of blood, as it flows from
the vessels through which it circulates in the living body,
is familiar to every one, as an opaque, slightly viscous
fluid, of a more or less brilliant red color; that from the
arteries being brighter and more scarlet than that fiom
the veins. It has, while warm, a faint though characteristic odor, differing in the blood of different animals, and
a saline and disagreeable taste. The specific gravity of
healthy blood appears to vary from 1050 to 1058, the
average being about 1055. It is always alkaline* to
test-paper, from the presence of an alkaline carbonate.
447. While circulating in the vessels, blood consists
of a nearly colorless and transparent liquid, in which
float myriads of minute vesicular bodies or corpuscles,
of which by far the greater number are of a bright red
color; and these, being so small as to be individually
quite invisible without the aid of a tolerably good microscope, give the blood, when seen with the naked eye, the
appearance of being a homogeneous red fluid (451). A
few of the corpuscles are colorless, and diffbr also in other
* In'certain morbid conditions an acid reaction has been observed
in the blood, due, it is said, to the presence of free lactic acid.
15




170   GENERAL CHARACTERS OF BLOOD.
respects from the red ones (464). The fluid portion of
the blood, in which the corpuscles float, is usually called
the liquor sangutinis.
44T. The most remarkable peculiarity presented by
the blood is the spontaneous coagulation which it begins
to undergo almost immediately after being drawn, gradually separating into a more or less firm and solid red
coagulum or clot, consisting of coagulated fibrin mixed
with the corpuscles, and a pale yellowish, transparent,
watery liquid, called the serum, holding in solution all
the other solid matters of the blood. The nature and
cause of this phenomenon will be more fully explained
further on (473).  The specific gravity of the serum  is
lower than that of the entire blood, being about 1029.
449. The chemical composition of the blood is highly
complex; and though the nature of the principal ingredients is now tolerably well understood, our knowledge
of the more obscure parts of its history is still very imperfect. The following substances appear to enter into
its composition (Simon), and probably further researches
will reveal the presence of other compounds, and, perhaps, also prove the non-existence of some of those now
included in the list.
Water,
f Albumen,
Protein compounds q Fibrin,
Globulin,
Coloring matters    Hemaptein,
Alcohol extractive (containing traces of urea),
Extractive matters
Water extractive,
( Cholesterin,
Serolin,
Fatty matters.. q Margaric acid,
Oleic acid,
L Red and white solid fats, containing phosphates
( Oxide of iron,
Albuminate of soda,
Phosphates of lime, magnesia, and soda,
Sulphates of potash and soda,
Saline matters. - { Carbonates of lime, magnesia, and soda,
Chlorides of sodium, and potassium,
Lactate, urate, and probably hippurate of soda,
L Oleate and margarate of soda,




BLOOD-CORPUSCLES.                    171
Oxygen,
Gases*....  Nitrogen,
Carbonic acid,
Sulphur,
Phosphorus.
450. It will, however, be more convenient for our present purpose, to consider the constituents of the blood as
arranged in the following manner, the more important
substances only being placed separately, and the others
being, for the sake of simplicity, grouped together:Water,
Red and white corpuscles,
Albumen,
Fibrin,
Alcohol extractive,
Water extractive,
Oily fats,
Crystalline or solid fats,
Fixed saline matters.
A  short description  of each of these substances and
groups, will assist in rendering the subsequent analytical
operations, both qualitative and quantitative, more simple
and intelligible to the student.
SECTION II.
Blood- Corpuscles.
451. If freshly-drawn blood, previous to coagulation,
be examined under the microscope, it will be found to
consist of a transparent and nearly colorless fluid, in
which float innumerable minute, circular, disk.shaped
bodies or corpuscles, of which by far the greater number
appear of a pale yellowish color, though they are in
reality red; the paleness of the color being caused by
the red rays from each of the corpuscles being spread
over so large a surface. It is to these corpuscles that the
red color and opacity of the blood are due; the liquor
sanguinis or fluid portion of the blood, in which they
float, being nearly colorless and perfectly transparent.
452. These minute bodies, which, when the blood is
* These gases appear to be contained, at least chiefly, in the bloodcorpuscles; tile serum has been shown to have very little power of
absorbing gases.




172              BLOOD- CORPUSCLES.
first drawn, float freely in the liquor sanguinis, occasionally
adhere together forming little aggregations resembling
strings of beads or rolls of coin
Fig. 63.       (Fig. 63); this arrangement, however, is not always permanent,
and the corpuscles gradually become again disunited and scattered.
The tendency to aggregate  together is usually greater during
the inflammatory state, frequently
causing the red corpuscles to collect in irregularly shaped masses,
Blood-corpuscles magnified 400 which  sink  more rapidly  than
diameters.      when they are detached from each
other. This is one of the causes
which tend to produce what is known as the buffy coat,
which was formerly supposed to be always indicative of
inflammation, but which has since been found to be
formed almost whenever the fibrin, from whatever cause,
coagulates more slowly, or the corpuscles subside more
rapidly, than in healthy blood (454, 473).
453. The red corpuscles of human blood have an average diameter of about  _o'~
Fig. 64.          of an inch.  They are nearly,),,        ) ~          circular, flattened disks, each
being slightly depressed and...:I) (      concave in the centre; their
)i  (thickness is usually about onefourth  or one-fifth  of their
diameter (Fig. 64).*
454. When, owing to the
Blood-corpuscles magnified 400 dia- solidification of the fibrin, the
meters.          blood coagulates (473), the
corpuscles gradually become
entangled ill the network of the solidifying clot, which
is, in consequence, of a bright red color; while the serum,
or defibrinated liquor sancguiis, is left nearly colorless as
* For further particulars relative to the structure of the blood-corpuscles, see Todd and Bowman's Physiological Anatomy and Physiology of Man.




BLOOD CORPUSCLES.                173
the clot subsides. In consequence of the corpuscles
being slightly heavier than the liquid in which they float,
they begin very slowly to subside almost immediately
after the blood is drawn; so that the lower portion of
the clot usually contains a larger proportion of them,
and has consequently a deeper color than the upper.
This is the case to a remarkable extent in certain morbid
conditions of the blood, which will be noticed further on
(589).
455. The red corpuscles appear to consist of delicate
membranous vesicles, filled with the red fluid to which
they owe their peculiar color, which fluid is supposed to
consist of a coloring matter containing a considerable
quantity of iron, to which the name of hbematin has been
given, associated with a protein compound, in many
respects analogous to albnmen, and called globulin. The
inclosing membrane, which is highly elastic, appears to
be composed either of coagulated fibrin or albumen, or
of somie other modification of protein closely allied to
them.
456. When placed in solutions of different densities,
the phenomena of endosmosis and exosmosis presented
by the corpuscles are very curious and interesting, and
may be seen with great facility with the help of a tolerable
microscope. As long as the fluid in which they float is
of the same density as that which they contain-such, for
instance, as the liquor sanguinis~-the corpuscles experience
little or no change of form. But if the external liquid
is less dense than that contained in the corpuscles, the
latter- will become more or less distended and globular,
owing to the lighter fluid, in obedience to the well-known
laws of endosmosis, passing through the membranous
vesicles into the interior more rapidly than the heavier
fluid within can pass outwards. If, on the other hand,
the external liquid be more dense than that contained
within the corpuscles, the contrary effect will be produced, and the corpuscles will immediately begin to
collapse and assume a wrinkled appearance (Fig. 65).
This change of form not unfrequently takes place spontaneously, while a drop of blood placed between two
surfaces of' glass is being examined under the micro15*




174             BLOOD-CORPUSCLES.
Fig. 65.         scope, especially near the
edges, where, owing to eva)       D 0        @  poration, the  liquid  with
s-' O                 which the corpuscles are in
X             ed -  contact gradually becomes
more concentrated, and con30g Q"               sequently more dense.'rQ  He Q   ~        457. The liquor sanguinis,
or fluid portion of the blood,
as it exists in the living
Blood-corpuscles eollapsed, magnified a
400diasieters.     body, and before it undergoes coagulation, appears to
possess the same density as the red fluid contained in the
vesicles; so that, as long as it continues so, no change
takes place in the form of the corpuscles. When, however, the fibrin which was before dissolved in the liquor
sanguinis, has coagulated, the resulting serum becomes
less dense, in consequence of its holding in solution a
smaller amount of solid matter (448). The effect of this
upon the blood-corpuscles is to cause them, when in contact with the serum of coagulated blood, gradually to
enlarge in size, in consequence of the increased rapidity
with which the less dense serum enters through the memrn
branous integument.
458. If the red corpuscles be brought in contact with
water, the change is extremely rapid; they instantly swell
to a much larger size, the vesicles becoming less and less
distinct, until at length, unless the quantity of water is
very small, they almost entirely disappear.
459. When, owing to the action of water, or some
other liquid of comparatively low specific gravity, the
corpuscles have become distended, they may, if the distension has not been allowed to go too far, be again
brought back almost to their original size, and even be
made to assume a wrinkled appearance, by bringing them
in contact with a tolerably strong solution of sugar, or
of certain salts, as chloride of sodiumn or chloride of ammonium.
460. The corpuscles readily dissolve in a solution of
potash, ammonia, acetic acid, and some other fluids,
461. Although we are unable to separate the corpuscles




BLOOD-CORPUSCLES.                 175
from the blood by filtration, since they pass readily
through the pores of the filter, it is found that when
mixed with certain strong saline solutions, they are retained by it. A solution of sulphate of soda, for example,
having a specific gravity of about 1-13, when mixed with
the blood, effectually prevents the passage of the corpuscles through the filter. This remarkable property
has been applied by Figuier to the purposes of analysis
(582)?.
462. When blood is allowed to dry at common ternperatures, and is subsequently moistened, even after the
lapse of considerable time, with some liquid having a
specific gravity similar to that of the serum (448), the
corpuscles are found to have retained their characteristic
form  and appearance, and may be readily distinguished
under the microscope. This circumstance has been ingeniously applied for the purpose of solving a question
which in some medico-legal inquiries is one of grave
importance, viz., whether the stains found on clothing or
elsewhere are or are not stains of blood.
463. For this purpose the stain is to be moistened,
and gently rubbed with a little fresh white of egg, or
some other fluid having a specific gravity of about 1030
to 1050. It is then scraped off; and a little of the mixture examined under the microscope with a tolerably
high power, when, if the stain consisted of blood, the
characteristic corpuscles will, in most cases be distinctly
visible.
It is, of course, desirable to obtain chemical as well as
microscopical evidence of the presence of blood in the
stain under examination. With this view, the stained
material should be soaked in a little water for an hour or
two, when, unless the stain be of long standing, a portion
of the blood will be extracted, imparting a dingy reddish
color to the liquid, to which the following tests should
then be applied:(a) Boil a portion in a test-tube; a dirty red coagulum
* According to Dumas, oxygen should be passed through the
liquid during filtration, and solution of sulphate of soda allowed to
drop into it, in order to prevent the obstruction of the pores of the
filter.




176            BLOOD- CORPUSCLES.
should be formed. On dissolving this in boiling potash,
the solution should be green by transmitted and red by
reflected, light.
(b) Chlorine-water should decolorize the liquid, and
produce a white flocculent precipitate.
(c) Nitric acid should produce a brown coagulum of
albumen and coloring matter. The albumen may also be
tested for with chloride of mercury, and with acetic acid
and ferrocyanide of potassium (137, 138).
(d) Evaporate the remainder of the solution to dryness,
and heat the residue, observing whether the offensive
odor of burnt blood is evolved. Incinerate the residue
completely, and boil the ash with a few drops of hydrochloric acid; dilute the solution with water, and test for
iron with ferrocyanide of potassium.
If the blood has not been extracted by soaking in water, the piece of stuff with the stain should be placed in
a stout glass tube, closed at one end, about half an inch
in diameter, and five or six inches long. About a
drachm of distilled water should be poured upon it, and
the tube drawn out and sealed before the blowpipe, at
about two inches from the open end. The sealed tube
is then heated to about 300~ to 3100 Fahr. for about an
hour.*  At this temperature the fibrin as well as the
albumen of the stain will dissolve in the water. When
the tube has cooled, it may be opened with a file, and
the liquid examined. It should have a yellow or reddish
color, and a feeble alkaline reaction to reddened litmuspaper. Of course, it would not be coagulated by heat,
but'nitric acid, chloride of mercury, and ferrocyanide of
potassium (after acidifying with acetic acid) should yield
precipitates.
The fabric from which the soluble matter has thus been
extracted, will generally retain some of the iron of the
blood, and may be examined, for further confirmation,
by the following tests:(a) If it be boiled in water containing a little tannic
* This may be effected either by suspending it in oil which is afterwards heated to that temperature, or by placing it in a hot-air bath.




BLOOD-CORPUSCLES.                 177
acid, or tincture of galls, it acquires a black or gray
color.
(b) The same piece may be boiled with a little dilute
hydrochloric acid, the solution diluted, and tested with
fcrrocyanide of potassium for iron.
(c) Another piece may be coiled with hydrochloric
acid, and the solution tested for iron with ammonia and
hydrosulphate of ammonia.
It is always advisable to repeat the above experiments
with an unstained portion of the same fabric, especially
if the latter be made of a colored material.
Identhfication of blood spots upon iron.-Spots of blood
are generally much more easily detached than those of
ordinary rust, and may be recognized by the following
tests:(a) Digest in water at about 1000 Fahr.  A recent
stain will be dissolved, and the solution may be tested
by boiling, by nitric acid, and by chlorine (see above).
(b) If water does not dissolve the stain,* boil it with
a dilute solution of potash, and test the solution with
nitric acid and chlorine.
(c) Heat a portion of the suspected rust in a tube, and
observe the odor.
(d) Heat another portion in a tube with a fragment of
solid hydrate of potash or soda; notice if any ammonia
is evolved during the fusion. All rust would evolve a
little ammonia; but an abundant evolution of this substance would afford some evidence of the presence of
blood. A part of the nitrogen contained in the blood
would be converted into cyanide of potassium, which
may be detected by dissolving the fused mass in water,
adding a little solution of protosulphate and perchloride
of iron, followed by an excess of acetic acid, which should
leave a blue precipitate (Prussian blue).
464. White corputscles of the blood.-In addition to the
red corpuscles, there are always present in the blood
* Rose (Journ. Pharm., xxviii. 436) has proved by direct experiment that hyvdrated peroxide of iron (rust) forms an insoluble compound with the coloring matter of the blood.




178                    HEM ATIN.
Fig. 66.           a few colorless particles,*'
somewhat larger than the
colored ones, and otherwise
differing from them in genQ% gyB'eral appearance and structure (Fig. 66).  They are
of irregular forms, sometimes  spherical, slightly
White Corpuscles of the Blood, magnified  granular on  the surface,
400 diameters.       and appear to be identical,
or nearly so, with the peculiar corpuscles always present in the lymph and the
chyle.  When treated with acetic acid, the granular exterior becomes transparent, as in the corpuscles of pus,
and one or more internal nuclei are rendered visible.
465. The proportion of corpuscles present in healthy
blood is usually about 130 parts in 1000 (573).t
465a. Hcemactn.-In order to separate the peculiar
coloring  matter of the blood-globules, freshly drawn
blood, which has been defibrinated by stirring, is mixed
with eight volumes of a saturated solution of sulphate of
soda, and set aside, in order that the globules may subside. The deposit is collected upon a filter, washed with
solution of sulphate of soda, boiled with alcohol containing a little sulphuric acid, and filtered while hot. The
globulin is then removed from the solution by precipitation with carbonate of ammonia, the filtered solution
evaporated to dryness on a water-bath, and all soluble
matters removed from the residue by boiling water, alcohol, and ether. By treating the residue with ammoniacal
alcohol, the haematin is dissolved, and may be further
purified by evaporating the clear solution to dryness, and
washing the residue with water.
The dark brown coloring matter thus obtained is remarkable for its containing a large proportion (6'6 per
cent.) of iron, its composition being represented (according to Mulder) by the formula C4422HNOFe. If it be
* These have a lower specific gravity than the red corpuscles, and,
therefore, accumulate on the upper surface of the clot.
t According to Denis, they contain one part of solid matter, and
1'8 of water.




BLOOD- CRYSTALS.                 179
digested with cold strong sulphuric acid, it forms a brown
liquid, and if this be diluted, hydrogen is evolved, and
a dark brown substance left, whilst sulphate of iron
(FeO,SO3) is found in solution. Chlorine also removes
the iron, but at the same time destroys the color, producing a white coagulum. In its general chemical
characters, habmatin resembles the albuminous class of
substances.
Hamatoichin, or bloodZ-crrystas. —When a drop of blood
is diluted with a little water on a slip of glass, lightly
covered with a piece of thin glass, and left in the sunlight
for some hours, minute red prismatic crystals of hbematoidin will sometimes be perceived.
Hmematoiden is also met with in old extravasations, and
Robin* has examined a mass of crystals of this substance,
weighing about fifty grains, obtained from a hydatid cyst
in the liver.  An analysis of these crystals led to the formula C14HE,8NO2+ HO, and Robin believes them to represent haematin which has lost all its iron, and acquired an
atom of water. The substance obtained by treating
bhematin with sulphuric acid has almost exactly the same
composition. Hernmatoidin is very sparingly soluble in
water, and insoluble in alcohol; but it dissolves in- ammonia, yielding a red solution.
Lehmann obtained a red crystalline substance from
the blood of guinea-pigs, rats, or mice, by washing the
clot with water, filtering the red liquid, and passing first
a current of oxygen, and afterwards carbonic acid. After
a time the crystals separate, and may be washed with a
little water. This substance, which has been named
haemato-crystallin, dissolves sparingly in water, the solution being coagulated by heat, but not by chloride of
mercury. In composition it somewhat resembles albumen, containing more nitrogen and less sulphur.  Much
obscurity still remains to be cleared up with respect to
these crystalline bodies obtained from blood.
Dr. Carter (" Ed. Med. Journal," August, 1859) obtained from serum a substance yielding indigo by decomposition, similar to that extracted from urine (page 40).
* Compt. Rend., xli. 506.




180              HEALTHY  BLOOD.
SECTION III.
Albumen.
466. This is one of the most important of the constituents of the blood, and, with the exception of the red
corpuscles, is present in larger quantity than any of the
other solid matters contained in it. It is held in solution in the serum, where it may readily be shown to
exist by gently boiling in a tube a little of the clear,
colorless fluid from which the coagulated clot of fibrin
and corpuscles has subsided. As soon as the temperature
reaches about 1700, the albumen begins to coagulate, and
on being boiled for a short time, separates entirely in the
insoluble form.
467. It may also be precipitated from its solution in
the serum, by adding to the clear fluid, a few drops of
dilute nitric or hydrochloric acid (136, 141). Acetic
acid fails to precipitate it; but if ferrocyanide of potassium be added to the acidified solution, a dense white
precipitate is produced, even when the albuminous liquid
is very dilute.
468. When gently warmed with strong hydrochloric
acid, albumen dissolves, forming a purple-colored solution, in which respect it resembles fibrin and casein.
469. When moistened with strong nitric acid, albumen
becomes yellow, owing to the formation of xanthoproteic
acid (2HO,C34H24N40,2), which, together with oxalic acid
(HO,C203), ammonia (NHII), nitric oxide (NO2), and nitrogen, is always formed by the action of strong nitric acid
on the so-called compounds of protein.
469a. Heated with a solution of nitrate of mercury
(HgO,NO,), albumen becomes intensely red (141a).
470. It appears from the results of numerous analyses
that the average amount of dry albumen present in
healthy blood is rather more than 70 parts in 1000 (578).
471. The composition of albumen is usually expressed
by Mulder's formula (C400H310N500o120S2P); but considerable uncertainty still hangs over the real nature of this




FIBRIN.                        181
class of bodies.* It is even doubtful whether any phosphorus exists in albumen, except in the state of phosphoric acid, as a constituent of the ash. By some chemists
albumen is regarded as containing C,,,,,,oN1sS20,,; and
since the serum of blood always contains nearly 2 per
cent. of soda, they consider it to consist of an albuminate
of soda, in which one atom of the above albumen is cornbined with each atom of soda. As the more important
peculiarities of albumen have been already noticed in
the chapter on morbid urine (133, 235, &c.), they need
not be again described.
SECTION IV.
Fibrin.
472. This substance, of which muscular fibre is chiefly
composed, is closely allied in chemical composition and
general properties to albumen; and it is, indeed, not improbable that both are, in their chemical relations, nearly
modifications of the same compound, which  from  the
circumstance of its being apparently the basis, not only
of albumen and fibrin, but also of casein (625) and some
other analogous substances, has been called protein, from,potEQ, I am first.t
-x The percentage composition of the three so-called protein comzpounds, albumen, fibrin, and casein, is as follows:Albumen.   Fibrin.    Casein.
Carbon.                  55-46      54'45     54'66
Hydrogen...    7'20         7'07      7'15
Nitrogen...   16'48        17'21     15'72
Oxygen....    1827         19X35     21'55
Sulphur....    216          1'59'92
Phosphorus  -...  43' 33
100'00    100'00   100'00
The mineral constituents, such as phosphate of lime, from which
these substances can never be completely separated, have been excluded from this calculation.
A peculiar modification of albumen (albumlinose or peptone) has been
observed in the liver and in blood, differing from  normal album
in not coagulating when heated, and from casein in not being precipitated by acids.
t The existence of protein as an independent proximate principle
appears very doubtful. Mulder represented fibrin as a compound of
(16




182                HEALTHY  BLOOD.
473. While circulating in the vessels, the fibrin of the
blood is held in a state of solution in the liquor sanguinis;
but no sooner is the blood removed from the system,
than it begins to separate in a solid state, after which it
becomes quite insoluble in water. This solidification of
the fibrin is the cause of the well-known phenomenon of
coagulation, which blood experiences almost immediately
after it is drawn; and al-though the coagulum or clot contains the blood-corpuscles in addition to the fibrin, these
have merely been entangled in the network of coagulating
fibrin, and do not themselves play any active part in the
process of coagulation.*
474. The coagulation of blood may be retarded, and
even altogether prevented, by the presence of certain salts
and other substances.  The alkalies, for example, and
their carbonates and acetates, entirely prevent it; and
tolerably strong solutions of sulphate of soda, nitrate of
potash, nitrate of lime, chloride of ammonium, and some
other salts, retard it for a considerable time.  The latter
salt, indeed, gradually dissolves fibrin, after it has been
allowed to coagulate. Most of the dilute acids, also,
cause blood to retain its fluidity, though it becomes,
under their influence, more viscous and syrupy in its
consistence.
475. Contact with certain animal membranes also appears to exercise a retarding influence on the coagulation
of the blood. When infused into the cellular tissue, it
has been known to continue uncoagulated for some weeks;
and even in a tied artery,. it remains some hours without
coagulating.
476. It appears from the experiments of M. Denis, that
if moist fibrin be digested in a solution of nitrate of
potash containing a little soda, at a temperature of about
1000 Fahr., it becomes gradually converted into a subten atoms of protein (C40,H,,N50,2) with one atom of sulphur and one
of phosphorus, but the presence of the latter, except in the ash of
fibrin, is disputed. The fibrin of muscle does not appear to be identical with that of blood, the latter containing a smaller proportion of
sulphur.
* According to Dr. Richardson, the coagulation of the fibrin is due
to the escape of ammeonia, by which it was previously held in -olution.




HEALTHY  BLOOD.                  183
stance in almost every respect identical with albumen;*
being soluble in water, and coagulable by heat. This
change is said to be most readily produced when the
fibrin employed in the experiment has been obtained
from venous blood, by allowing it to coagulate spontaneously; while, if it is separated by agitation, or if the
blood be arterial, it scarcely experiences any alteration
in the saline solution. By drawing blood into a solution
of sulphate of soda, so as to prevent the coagulation of
the fibrin, filtering off the globules, and saturating the
filtrate with chloride of sodium, Denis obtained a precipitate of fibrin, which dissolved in water, forming a
solution which gave, after a short time, a transparent
coagulum of fibrin.
477. Pure fibrin may be obtained without difficulty, by
receiving the blood, as it flows from the body, in a clean
porcelain dish, and stirring it well for some little time
with a glass rod; or the blood may be shakeh with a few
small fragments of lead, in a closed glass flask. The
fibrin, as it coagulates, collects in loose fibrous masses
round the rod or fragments of lead, colored slightly red,
owing to the imprisonment of a few corpuscles within
the network of fibrin. These may be removed by tying
the coagulum in a piece of fine muslin, and washing it
under a stream  of cold water until the mass becomes
colorless. In this state, it still contains traces of fatty
matter and inorganic salts, together with a considerable
amount of water. To obtain the fibrin, therefore, in a
state of perfect purity, the washed coagulumn must be
dried on a chloride of calcium bath at a temperature of
about 2500, and the dry mass then reduced to fine powder
in a mortar. The pounded fibrin may afterwards be
washed successively with alcohol, ether, and dilute hydrochloric acid; and lastly, macerated with cold or lukewarm
water, until all the soluble matter is removed; after
which it may be dried as before at a temperature of about
250~.
478. If the blood from which we wish to extract the
X Fibrin suffers a similar change when heated with water to about
3000 Fahr., in a sealed tube.




184              HEALTHY  BLOOD.
fibrin has already coagulated, the clot is first gently
pressed between folds of bibulous paper, in order to
squeeze out the greater part of the adhering serum, and
then cut into thin shreds with a sharp knife. The finelydivided clot is then washed in a muslin bag under a
gentle stream of cold water, until it becomes colorless,
by which means the imprisoned corpuscles are washed
out of the fibrous mass. The latter is then dried, and
reduced to powder, and subsequently purified by washing
and drying in the manner above described (477).
479. Fibrin thus prepared is a pale, yellowish, hornylooking substance, hard, brittle, and, if all traces of fat
have been removed, transparent.  It is perfectly tasteless,
and insoluble in water, alcohol, and ether; if kept for a
short time in water, however, it gradually softens, swells
up, and reassumes the appearance it had previous to
desiccation.  When digested with acetic and most of the
other acids,'fibrin becomes gelatinous, and is in that state
soluble in water. The acid solution, when treated with
ferrocyanide of potassium, gives a copious white precipitate, similar to that caused in albuminous solutions.
Fibrin is also dissolved by digestion in a dilute solution
of nitre, the liquid coagulating when heated. Like albumen, and the other modifications of protein, it forms,
when gently warmed with strong hydrochloric acid, a
purple-colored solution. With nitric acid, also, fibrin
behaves like the other protein compounds, forming the
yellow xanthoproteic acid (469). It, also becomes red
when heated with solution of nitrate of mercury (141a).
479a. The fibrin of muscle (sometimes called syntonin)
differs somewhat in properties from that of blood. It
does not dissolve in a dilute solution of nitre, but may be
dissolved by digestion in very dilute hydrochloric acid
(1 of acid to 1000 of water), whilst blood fibrin swells up
and becomes transparent, but does not dissolve.
480. When examined under the microscope, coagulated
fibrin appears to consist of a rude network of amorphous
threads, together with detached aggregations of irregular
form, similar to albumen.
481. The average proportion of dry fibrin present in
healthy blood appears to be rather more than two parts
in a thousand (573).




HEALTHY BLOOD.                   185
SECTION V.
Extractive Matters.
482. Of the real chemical nature of the substances
included under the name of extractive matters, little is
yet definitely known, though they have frequently engaged the attention of chemists. It is probable, however,
that further researches will, ere long, throw new light
upon this at present obscure class of substances. They
-include all the undefined, uncrystallizable organic matters
which are soluble in water; or, in other words, the
extractive matters of the blood may be said to include all
the organic substances contained in it, with the exception
of the corpuscles, albumen, fibrin, and fatty matters.
483. Extractive matters are usually divided into alcohol
extractive and water extractive; the first including that
portion which is soluble both in water and alcohol; and
the latter, that which is soluble in water and insoluble in
alcohol. They are of a brown or yellowish color, and are
characterized by their solutions giving brown precipitates
with acetate of lead, but none with bichloride of mercury.
A solution of the alcohol extractive is precipitated by an
infusion of galls, wdhich reagent causes little or no change
in the water extractive.
484. Traces of urea are probably always present in the
blood, and would be contained in the alcohol extractive.
The method of detecting it will be described further on
(598). The minute traces of uric acid which appear to
be usually present even in healthy blood, would be contained in the water extractive; the mode of detecting them
is described in paragraph 604.:
485. The amount of extractive matters present in
healthy blood seems to vary from one to three parts in a
thousand.
* Sugar has been discovered in minute proportion in normal blood.
Campbell has also indicated the presence of a little formic acid in the
serum.
16*



186               HEALTHY  BLOOD.
SECTION VI.
Fatty Matters.
486. Our knowledge of the fatty matters contained in
the blood is at present far from being complete. They
are usually divided into oily fats and crystalline fats; the
first being soluble in cold alcohol, and the latter insoluble.
The oily fats appear to consist chiefly of oleic (HO, CG
H33 03) and margaric (HO, C34H33 03) acids; the crystalline
fatty matter is probaly a mixture of serolin with traces
of cholesterin (C,,2I4402), together with one or more solid
fats containing phosphorus.*
487. To obtain these fatty matters, a quantity of blood
is evaporated to dryness on a water-bath, and the dry
residue, after being reduced to powder, is digested in hot
ether, successive portions of which must be added as long
as anything appears to be dissolved by it. The ethereal
solution is then evaporated to dryness on a water-bath,
and the residue, consisting of the mixed fats, treated with
cold alcohol, which will dissolve out the oily fats, and
leave the crystalline matters undissolved. The first may
be obtained by evaporating the alcoholic solution on a
water-bath; and the undissolved crystalline fats may be
dissolved in boiling alcohol, from which they will almost
entirely separate, as the liquid cools, in the form of small
crystalline scales.
488. The quantity of fatty matters present in healthy
blood appears to vary from 1-5 to 2-5 in 1000 parts (573).
SECTION VII.
Fixed Saline Matters.
489. The ash left after the incineration of the dry
residue of evaporated blood appears to contain the following substances: —viz., the chlorides of sodium and potassium; the phosphates of lime, magnesia, and soda; the
* The serum also contains minute proportions of one or more of the
volatile fatty acids (e. g. butyric or caproic), as shown by the odor
which is developed on mixing the blood with sulphuric acid, and
varies in different animals.




HEALTHY BLOOD.                  187
sulphates of potash and soda; and oxide of iron derived
from the hbematin (455). If the ash has been obtained
by the incineration of the serum, traces of alkaline and
earthy phosphates will probablyfbe rendered apparent by
the effervescence caused by the addition of an acid; but
if the ash has been obtained by the incineration of the
entire blood, no trace of carbonates will be observable on
the addition of the acid. The cause of this appears to
be, that some of the fatty matters present in the clot
contain traces of phosphorus (486)' which, during combustion, is converted into phosphoric acid (PO,); and the
phosphoric acid thus formed decomposes the small quantity of carbonates derived from the serum, converting
them into phosphates.
490. The saline matters of the blood may be conveniently divided into the alkaline salts, which readily dissolve
in water, and the earthy salts, which require an acid for
their solution. The alkaline portion of the ash consists
of the chlorides of sodium and potassium; the sulphates
of potash and soda; the phosphate, with possibly traces
of carbonate (489) of soda. The earthy or insoluble
portion contains the phosphates of lime and magnesia;
oxide of iron derived from the red coloring matter; and
possibly a little earthy carbonate (489). The presence
of the bases and acids contained in these several salts
may be shown by the following experiments.
491. Digest from twenty to thirty grains of the ash in
warm, water, in order to dissolve out the alkaline salts,
and filter the solution from the insoluble portion. The
aqueous solution thus obtained may be first tested, retaining the earthy residue for subsequent examination (499).
492. If the aqueous solution is at all dilute, it should
first be concentrated by evaporation. To a little of the
concentrated solution, add a slight excess of tartaric acid
(2HO, H84IO,o), and agitate the mixture with a glass rod.
A colorless crystalline precipitate of the bitartrate shows
the presence of POTASH.
493. To another portion of the solution add a solution
of bichloride of platinum (PtCI,), and allow the mixture
to evaporate to dryness, either spontaneously or at a very
gentle heat. Minute, yellow, granular crystals of the




188             HEALTHY BLOOD.
double chloride of platinum and potassium (KCl,PtCI2)
will be found deposited, also showing the presence of
POTASH. In addition to these will be seen long, yellow,
needle-shaped crystals of the double chloride of platinum
and sodium, proving the presence of SODA. If the bichloride of platinum has not been added in sufficient quantity
to combine with the whole of the soda, a few detached'cubical crystals of chloride of sodium will also be
deposited, which may be proved to be such by their
well-known taste.
494. The presence of soda may also be shown by
adding to a little of the strong aqueous solution a few
drops of antimoniate of potash (KfO,SbO,), which will
gradually cause a colorless crystalline precipitate of antimoniate of soda (NaO,SbO5).
495. To another portion of the aqueous solution of the
ash, add a solution of chloride of barium, or nitrate of
baryta, as long as it causes any precipitate. The sulphuric, phosphoric, and (if any (489) ) carbonic acids are
thus thrown down in combination with baryta. The
mixture containing the precipitate thus produced is now
strongly acidified with hydrochloric acid, and warmed. If
effervescence occurs on the addition of the acid, CARBONIC
ACID is probably present. The presence of SULPHURIC
ACID is shown by a portion of the precipitate (sulphate
of baryta) proving insoluble in the acid.
496. Filter the acid mixture formed in (495), and
neutralize the filtered liquid with ammonia. The phosphate of baryta (2BaO,HO,PO5),which had been dissolved
by the acid, is reprecipitated, indicating the presence of
PHOSPHORIC ACID (498).
497. Acidify another portion of the aqueous solution
of the ash with nitric acid; add a slight excess of nitrate
of silver, and filter the liquid from the white precipitate
occasioned by the silver salt. This precipitate may be
proved to consist of chloride of silver (HYDROCHLORIC
ACID), by being readily soluble in ammonia, and insoluble
in nitric acid.
498. Accurately neutralize the acid solution formed in
(497), with dilute ammonia; the pale yellow phosphate
of silver (3AgO,P05), which had been held in' solution by




HEALTHY BLOOD'.                 189
the excess of acid, will now be precipitated, showing the
presence of PHOSPHORIC ACID (496).*
499. The earthy portion of the ash, which proved
insoluble in water (491), may now be examined. It is to
be dissolved in as small a quantity as possible of dilute
hydrochloric acid, a gentle heat being applied if necessary.
If effervescence occurs on the addition of the acid, CARBONIC ACID is present (489).
500. A little of the acid solution may now be nearly
neutralized with dilute ammonia, which should not be
added in sufficient quantity to cause any precipitate. The
liquid is then tested with a drop or two of a solution of
ferrocyanide of potassium, which will cause, either at once
or in the course of a few minutes, a blue color, owing to
the formation of the ferrocyanide of iron (Fe4Fcy3), showing the presence of IRON.
501. The rest of the acid solution of the earthy portion
of the ash may now be supersaturated with ammonia,
which will throw down a white gelatinous precipitate of
earthy phosphates. A little of this precipitate may be
examined under the microscope, when it will be found
to consist chiefly of amorphous particles of phosphate of
lime (3CaO,PO,), with a few crystals of the double phosphate of ammonia and magnesia (2MgO,N1E40,PO,+
12Aq). The precipitate thrown down by the ammonia
may also be examined for LIME, MAGNESIA, and PHOSPHORIC ACID by redissolving it in acetic acid, and testing
the solution in the manner described in paragraph 47.
502. The quantity of alkaline salts usually present in
healthy blood, varies from about six to ten parts in 1000;
and that of earthy salts from 0'5 to 1'5 in 1000 parts.
* The phosphoric acid may be detected with greater certainty by
perchloride of iron, or the mixture of sulphate of magnesia, chloride
of ammonium and ammonia (41).




190   QUANTITATIVE ANALYSIS OF BLOOD.
CHAPTER II.
QUANTITATIVE ANALYSIS OF THE BLOOD.
503. A COMPLETE quantitative analysis of the blood,
including the separation from each other and estimation
of all the ingredients, would be, even if our knowledge
and resources were much less limited than they are, in
the highest degree complicated and difficult, while at
present it may be said to be altogether impracticable.
For most purposes, however, a comparatively incomplete
analysis, embracing the determination of the more important ingredients, is all that is required; and in the
majority of cases a knowledge merely of the proportion
of fibrin, the corpuscles, and the solids contained in the
serum, is what the medical practitioner chiefly requires.
504. I will first describe the mode of conducting such an
analysis, by which the amount of water, corpuscles, fibrin,
and solids contained in the serum may, with very little
difficulty, be ascertained; and subsequently go through
a somewhat more complete scheme, by which, in addition.to the above substances, the more important constituents
of the serum may also be individually estimated. (See
sections 3 and 4.)
505. When the blood intended for analysis can be collected in the proper vessels as it flows from the body, the
process is somewhat simpler than when it has been allowed to coagulate; and the results are generally more
accurate. As, however, this is frequently impracticable,
I will also describe the method by which the analysis of
coagulated blood may be effected.




QUANTITATIVE ANALYSIS OF BLOOD.   191
SECTION I.
Quantitative Analysis of Uncoagulated Blood, including the
estimation of the water, corpuscles, fJibrin, and the solid
matters contained in the serum.
506. Before proceeding to collect the blood as it flows
from the body, for the purpose of analysis, the experimenter should provide himself with three vessels, the
exact weight of each of which is to be carefully ascertained and noted. These vessels are:I. A six or eight-ounce bottle provided with a stopper;
this bottle should be perfectly clean and dry, and of
known weight. Eight or ten small strips of thin
sheet lead, about half an inch square, the weight of
which should also be known, are put into the bottle,
which will then be ready to receive the blood (507).
This bottle is used for efiecting the separation of the
fibrin.
2. A small platinum  or Berlin porcelain capsule, capable of holding from half an ounce to an ounce of
water. This is used for estimating the proportion
of water in the blood (508).
3. A rather tall, upright beaker, or cylindrical glass,
capable of holding about six ounces of water.
507. The blood may now be collected. About five or
six ounces of the fluid are first poured into the bottle
containing the fragments of lead, which should then be
tightly closed with the stopper, and kept gently agitated
for about a quarter of an hour, in order to allow the
whole of the fibrin to coagulate, and attach itself to the
pieces of lead (477). This portion of blood we will call
A (510).
508. Two or three drachms of blood are collected in
the capsules, which is then again accurately weighed, and
the weight of the empty capsule, previously ascertained
(506), deducted from the gross weight, in order to determine the exact quantity of blood contained in it. It may
then be placed on a water-bath, and evaporated to dryness. This portion we will call B (514).
509. The beaker, or cylindrical glass, is to be nearly
filled with the fi-eshly drawn blood, covered with a glass




192   QUANTITATIVE ANALYSIS OF BLOOD.
plate and set aside in a tolerably cool place for twentyfour hours; at the end of which time it will be found to
be thoroughly coagulated, and separated into a firm clot
and clear serum. This portion we will call C (516).
510. Treatment of the _portion A.-When the blood has
been gently shaken for about a quarter of an hour, immediately on being placed in the bottle (507), the fibrin will
be found to have separated, and collected round the fragments of lead which have been previously introduced.
The outside of the bottle is then cleaned with a wet cloth,
and wiped dry.
511. The weight of the bottle, with its contents, is now
taken, in order to ascertain the exact quantity of blood
employed in the experiment, which is known by deducting from the gross weight that of the empty bottle and
the lead, the difference being the weight of blood contained in it.
512. The stopper is now removed, and the contents of
the bottle poured out upon a piece of fine muslin placed
in a small basin or saucer. The liquid portion is carefully drained off, and may be thrown away; after which
the fibrin adhering to the lead is to be washed with a
gentle stream  of cold water, until it becomes colorless,
in order to separate from it the whole of the corpuscles
and serum. During the washing, the spongy aggregations of fibrin may be gently pressed occasionally between
the fingers, care being taken that none of the fragments
are lost. When clean, the fibrin is to be placed in a
small evaporating dish, and dried on a chloride of calcium bath, at a temperature of 220~ or 2300, until it
ceases to lose weight. It is unimportant whether it is
dried and weighed with the pieces of lead, or first separated from  them, since the weight of the lead, being
known (506), may be deducted from the gross weight of
the lead and fibrin, the difference being that of the fibrin.
513. The weight thus obtained represents the proportion of FIBRIN in the quantity of blood used in the
experiment; the proportion in 1000 parts of blood may
afterwards be ascertained by the following calculation:Wt. of blood ). Wt. of fbrin:100    tity of fibrin in
ernployed.    obtained. f        1000 parts of blood.




QUANTITATIVE ANALYSIS OF BLOOD.   193
514. Treatment of the portion B.-The capsule containing the portion B, after being accurately weighed (508),
is allowed -to remain on the water-bath (or still better, on
a chloride of calcium bath, heated to about 2200 or 230~),
until it ceases to lose weight on being weighed at intervals of half an hour or an hour, care being taken to wipe
the outside clean and dry each time. When the weight
becomes constant, it may be concluded that the whole of
the water has been expelled.
515. From the weight thus obtained that of the empty
capsule is now to be deducted; the difference being the
weight of the ENTIRE SOLID MATTER contained in the
quantity of blood operated on. The diftference between
the weight of this dry residue and that of the blood before evaporation, or, in other words, the loss which it has
experienced during the evaporation, will then represent
the amount of WATER contained in the quantity of blood
employed in the experiment. The proportion of solid
matter present in 1000 parts of the blood, may therefore
be calculated in the following manner:(  Wt. of    Wt. of        f Proportion of solid
blood:   dry::1000    matter in 1000
evaporated.    residue.       parts of the blood. J
516. Treatment of the portion C.-The third portion of
blood which was collected in the beaker (509), is allowed
to stand for about twenty-four hours, or until it separates
into a firm clot and clear serum. Two or three drachms
of the clear serum are carefully poured off from the clot
into a small platinum or porcelain capsule, similar to that
before used (506), the weight of which has been previously
accurately noted. The capsule with the serum is now
weighed, to ascertain the quantity of the latter employed
in the experiment, and then evaporated to perfect dryness on a chloride of calcium bath at a temperature of
about 230~, until it ceases to lose weight. The loss of
weight which it experiences during evaporation, represents the amount of water in the quantity of serum used;
while the weight of the dry residue shows the amount of
solid matter contained in the same quantity of serum.
517. From the numbers now obtained, we are enabled
to calculate the proportion of the SOLID MATTERS OF THE
17




191-   QUANTITATIVE ANALYSIS OF BLOOD.
SERUM in 1000 parts of blood, in the following manner.
Knowing, as we do, the quantity of water in 1000 parts
of the blood (515); and assuming that the water of the
blood exists wholly in the form of serum;* knowing also
the proportion of water and of solid matter contained in
the serum (516); we may, from the quantity of water in
the blood, estimate the quantity of solids held in solution
in the serumrn, thus:Wt. of water     Wt. of solid 1     Water in 1      Solids ]
W.owa   matter in      0ts         of serum
in the quan-                    1000 pts.    in 0
titemployed.   I ty of serum    blood  pts. of the J
employed.    1 employed. JI            J      blood. J
518. We have now determined the proportion of water,
fibrin, and solid matters of the serum, contained in the
blood, and have only to ascertain the weight of the couPUSCLES in order to complete the analysis.  This is done
by adding together the weights of the fibrin and the
solids of the serum contained in 1000 parts of blood, and
deducting the sum  of them from the weight of the entire
solid matter, which consists of fibrin, solids of the serum,
and corpuscles; the difference, therefore, will represent
the proportion of the latter in 1000 parts of the blood.
519. The several results now obtained may be recorded
thus; and the numbers, when added together, should
amount to within a fraction of 1000.
Water.
Corpuscles.
Fibrin.
Solid matters of serum..
1000.00
SECTION II.
Quantitative Analysis of Coagulated Blood, including the estimation of the water, corpuscles, fibrin, and the solid matters
contained in the serum.
520. The portion of blood intended for analysis, which
may consist of about ten fluidounces, should be collected
* Of course this assumption introduces an error into the analysis,
since the water belonging to the contents of the globules is imputed
to the serum.




QUANTITATIVE ANALYSIS OF BLOOD.   195
in a weighed or counterpoised glass beaker, or other
cylindrical vessel, and accurately weighed; or if it has
been accidentally collected in any vessel of which the
weight has not previously been determined, it may be
weighed as before, and the weight of the containing
vessel, ascertained after the blood has been removed, de.
ducted from the gross weight; the difference being, of
course, the weight of the blood employed. The blood,
after being collected, is to be set aside in a tolerably cool
place for about twenty-four hours, to allow it to coagulate; the top of the glass being covered with a glass plate
or small dish, to preserve it from dust and prevent evaporation.
521. About two or three fluidrachms of the clear
serum are to be drawn off with a pipette, or carefully
poured off, into a small weighed platinum or porcelain
capsule; after being accurately weighed, it is to be evaporated until it ceases to lose weight, on a chloride of
calcium  bath, kept at a temperature of about 2200.
When dry, the weight is noted; the loss during evaporation representing the amount of water in the quantity
of serum operated on, and the weight of the dry residue
being that of the solid matter contained in the same. The
relative proportions of solid matter and water which form
the serum are thus ascertained.
522. While the evaporation of the serum (521) is going
on, the examination of the rest of the coagulated blood
may be proceeded with. The serum  is first poured off
from the clot with great care, avoiding the escape of any
portion of the coagulum; the last portions of the liquid
being removed by means of a fine-pointed pipette, or by
introducing one end of a folded piece of bibulous paper,
which will suck up the liquid until it is saturated, and
may then be replaced by another. This serum, although
it will probably not be wanted for any subsequent experiments, had better be for the present retained, in case of
any accident happening to the portion already taken for
evaporation (521).
523. The clot, thus separated from the greater part of
the serum, is now to be divided, by means of a sharp




196    QUANTITATIVE ANALYSIS OF BLOOD.
knife, into two portions of equal weight;* the weight of
both being accurately made to correspond by weighing,
and adding or taking off small slices, as necessity may
require. When this is done, each portion will contain
one-half the fibrin and corpuscles of the quantity of blood
operated on, together with a certain amount of serum.
One of these equal portions of the clot we will call A,
and the other B.
524. 2Teatment of the portion of clot A. —This is to be
cut into thin shreds with a clean, sharp knife, carefully
avoiding any loss of the fragments of the coagulum. The
finely sliced clot is then tied up in a piece of fine muslin,
or calico, and washed under a gentle stream of cold water,
with the assistance of occasional pressure between the
fingers and thumb, until the whole of the serum and corpuscles are removed from the interstices of the coagulum,
and the fibrin is left quite clean and colorless. It is then
taken out of the muslin, and' dried on a chloride of calcium bath, until it ceases to lose weight. The weight
thus obtained represents the fibrin contained in half the
clot, and when multiplied by two, gives the proportion
of FIBRIN in the quantity of blood employed.t
525. Treatment of the p2ortion of clot B.-The weight of
the portion B having been noted, it is to be evaporated
to dryness on a chloride of calcium bath in a counterpoised or weighed capsule. The loss of weight which it
experiences during evaporation, shows the quantity of
water contained in half the clot, which, when multipled by
two, gives the amount of water present in the entire clot;
while the weight of the solid residue, also multiplied by
two, shows the quantity of solid matter which the entire
clot contains.
526. From the data thus obtained, we are enabled to
calculate the proportion of the several constituents, in
the following manner. Having ascertained the weight
* The division must be made vertically, since the horizontal layers
of the clot contain different proportions of globules, being richer
towards the bottom. The exact equality of the two parts of the clot
is only necessary to save subsequent calculation.
t To obtain an exact result, this fibrin should be treated with ether
to remove fat, then with alcohol, and again dried and weighed.




QUANTITATIVE ANALYSIS OF BLOOD.   197
of the whole solid matter of the clot (525), which consists
of fibrin, corpuscles, and solids contained in the portion
of serum with which the clot is saturated, we first calculate how much of the weight is due to the solids of the
serum. To do this, we assume that the whole of the
water present in the clot is due to serum; then, knowing
from a previous experiment (521), the relative proportion of water and solid matter in the serum, and knowing also the quantity of water contained in the clot (525),
we calculate the amount of solid matters in the clot,
which belong to the serum, as follows:Wt. of water   rWt. of solid j   (Wt. of    (Wt. of solid 1
in quantity     matter ill      water ]    matters of.  of serum     quantity of    in the: i serum con-G
L          J  L evaporated.J   l clot. J  L entire clot. J
527. The weight thus calculated, of solid matters of
serum present in the clot, is deducted from the weight of
the entire solid matter contained in. the clot (5-25), and
the difference will represent the weight of the fibrin and
corpuscles.  Having, therefore, previously determined,
by a separate experiment (524), the amount of fibrin, we
have only to deduct that number, in order to obtain the
proportion of CORPUSCLES in the quantity of blood
operated on. -.
528. Knowing now the amount of the fibrin and corpuscles, we can, by deducting their combined weights
from that of the entire blood, learn the quantity of serum
which it contained; since the blood is wholly composed
of fibrin, corpuscles and serum.
529. From the weight of serum thus obtained, assuming that the whole of the water in the blood is due to the
serum, we can calculate that of the WATER and SOLID
MATTERS OF THE SERUM contained in the entire blood, in
the following manner, since we have before determined,
by experiment (521), the relative proportions:For the Water.
(Wt.of serum 1,  r Loss of 1   (Wt. of serum    ( r Proportion. 1
<which was {  t wt. dur-    in quantity    of water in
evaporated: ing eva-   blood         quantity of blood
l to dryness. J  L poration. J   l   used.  J  l blood used. J
17'




198    QUANTITATIVE ANALYSIS OF BLOOD.
For the Solid Matters of the Serum.
r Weight of 1  (rWt. of so- -    [ Weight of'  [Wt. of solid'}
serum which I  l lid residue    serum in     matters of
was evapo-:- of serum::  quantity        serum in -
rated to dry-      after eva-   of blood     qantity of
ness.   J   l poration. J  [    used. J   blood used. J
530. We shall now, therefore, have ascertained the
proportions of the four several constituents required, in
the quantity of blood employed in the analysis, viz:Water.
Corpuscles 
Fibrin.
Solid matters contained in the serum.
which, when added together, should amount very nearly
to the weight of the blood used.
531. In order to determine the proportion of the several
constituents present in 1000 parts of the blood, the following calculation will in each case be necessary: —
(Wt. of blood ]  Weight of ]  Proportion of that
employed     1000     each con-         onstituent in
i in the             stituent       1000 parts of the
L analysis. J          l obtained. J    L    blood.
SECTION III.
Quantitative Analysis of Uncoagulated Blood, including the
determination of the water, corpuscles, albumen, fibrin,
alcohol extractive, water extractive, oily fats, crystalline or
solid fats, and fixed saline matters.
532. The vessels required for the analysis are nearly
the same as those already described in the shorter scheme
of analysis (506), viz:1. A six or eight-ounced stoppered bottle, the weight of
which is accurately known; and in which are placed
a few small strips of thin sheet lead, the weight of
which is also known.
2. A weighed platinum capsule or crucible, capable of
holding rather more than an ounce of liquid; or, in
default of this, a thin Dresden porcelain crucible, of
about the same capacity. And




QUANTITATIVE ANALYSIS OF BLOOD.   199
3. A tall upright beaker or cylindrical glass, capable
of holding about eight ounces of liquid. The weight
of this need not be taken.
533. The three vessels being in readiness, the blood is
first to be collected. About six ounces of the fluid are
allowed to flow into the bottle, which should immediately
be closed with the stopper, and gently shaken for a
quarter of an hour or twenty minutes, at the end of
which time the fibrin will be found to have separated
from the liquid, and attached itself round the fragments
of lead. This portion of blood we will call A (536).
534. About an ounce of blood is collected in the
weighed capsule or crucible, and, after being weighed
for the purpose of ascertaining the exact quantity of blood
employed, it is placed on a water-bath or chloride of
calcium bath, and allowed to evaporate. This portion
we will call B (539).
535. From six to eight ounces of blood are allowed to
flow into the beaker, and set aside to coagulate in a
tolerably cool place for about twenty-four hours. This
portion we call C (541).
536. Treatment of the portion A.-As soon as the fibrin
is supposed to have separated completely from the blood,
and become attached to the pieces of lead, the outside of
the bottle is to be wiped clean and dry, and the whole is
weighed; when the difference between the combined
weights of the erhpty bottle and the lead, and that of the
whole when filled, will represent the quantity of blood
employed in the experiment.
537. The contents of the bottle are now to be emptied
out upon fine muslin, in a small evaporating basin, and
the fibrin is to be carefully separated from the fragments
of lead, to which it adheres loosely. It is then washed,
under a gentle stream of cold water, from the serum and
corpuscles with which it is saturated, carefully avoiding
the loss of any particles of the fibrin.
538. When quite clean and colorless, the fibrin is
placed in a platinum or thin porcelain crucible of known
weight, and dried on a chloride of calcium bath, at a
temperature of about 2200 or 230~, until it ceases to lose




200    QUANTITATIVE  ANALYSIS OF BLOOD.
weight.? When dry, the weight is noted. As the
fibrin, in its present state, contains traces of earthy phosphates, which add slightly to its apparent weight, it may
now be incinerated in the crucible, until the ash becomes
white or gray. The loss of weight which the dry fibrin
experiences during incineration, represents the amount
of pure FIBRIN in the quantity of blood that was contained
in the bottle. The proportion present in 1000 parts of
the blood may then be calculated as follows: —
{ Weight of     Weightf             Proportion of (
blood:    fibrin::1000: fibrin in 1000
employed.      obtained.            parts of blood.
539. Treatmrent of the portionr  B.-This portion of the
blood, after being weighed, is allowed to remain  on a
chloride of calcium bath, heated to about 220~, until it
ceases to lose weight; when it may be concluded that
the whole of the water has been expelled. When this is
the case the weight is noted; and the proportion of SOLID
MATTERS OF THE BLOOD  contained in 1000 parts of the
fluid may be calculated as follows:{ Wt. of blood )( Weight of           Proportion of solid'
evaporated:    dry        1000    matter in 10(0 0
to dryness.     residue. )            parts of blood.
540. The dry residue (539), after being weighed, is to
be incinerated in the capsule or crucible until the whole
of the charcoal of the organic matter is burnt away, and
the ash becomes of a pale red color.t  The weight of
the ash thus obtained shows the amount of FIXED SALINE
MATTER in the quantity of blood evaporated; and from
this, the proportion contained in 1000 parts of the blood
may be thus estimated:{ Weight of      W wt. of ash)       (Proportion of fixed)
blood    i   after in-::1000:  saline matter in
evaporated.    cineration.         1 1000 pts. of blood. )
F* or greater accuracy, it is well to weigh the piece of muslin, dried
at 220~, before collecting the fibrin upon it, so as to avoid the necessity of removing the fibrin before drying.
I A muffle heated to very low redness will be found very convenient
for this incineration, which takes place very slowly over a lamp. A
small charcoal fire is better than the latter.




QUANTITATIVE ANALYSIS OF BLOOD.   201
541. Treatment of the portion C. —This portion of blood
is allowed to stand for about twenty-four hours, in order
that it may coagulate spontaneously, and divide itself
into a firm clot and perfectly clear serum.
542. Two or three fiuidrachms of the serum are first
removed from the surface and placed in a small platinum
or porcelain capsule, the exact quantity of serum taken
being ascertained by again weighing the capsule and its
contents. It is then placed on a chloride of calcium
bath, and when perfectly dry, again weighed, in order to
determine the relative proportions of solid matter and
water in the serum; the weight of the dry residue and
the amount of loss during evaporation representing respectively the proportion of solids and of water in the
quantity of serum employed.
543. From the numbers thus obtained, we are able
(assuming that the whole of the water in the blood exists
in the form of serum) to estimate the quantity of SERUM
contained in 1000 parts of the blood, since we have before
ascertained the amount of water in 1000 parts of blood
(539), and also the relative proportion which the serum
bears to the water contained in it (552), thus:f Wt. of water Ir Weight of    (Weight of    Weight of 
in the quan-    serum         water        serum
tity of serum  which was     in 1000      in 1000
that was      evapo-         parts        parts 
evaporated    rated to         of           of
to dryness. J  L dryness.  l blood.    1  blood.  J
544. Another portion of the clear serum, weighing
exactly 500 grains, is now to be weighed olt in a platinum or porcelain capsule, and evaporated to dryness on
a water-bath. This will serve for the estimation of the
albumen, oily and crystalline fats, and alcohol and water
extractives.
545. The dry residue is to be detached, with the aid
of a knife, from the capsule, and reduced to fine powder
in a mortar. As it is impossible to effect this without
loss the weight of the powder must be ascertained. A
small light flask (perfectly dry) is weighed, and the
powder introduced into it, the increase of weight being
noted. Half an ounce of ether is then poured into the




202    QUANTITATIVE  ANALYSIS OF BLOOD.
flask, and a gentle heat applied by a water-bath* for
about ten minutes, when it may be carefully poured off
and replaced by a fresh portion.
546. The ethereal solution thus obtained, containing
the fatty matters, both oily and crystalline, is to be evaporated in a capsule of known weight, on a water-bath,
until the whole of the ether is expelled. The residue is
now weighed, by which the whole amount of fatty matters
is ascertained. It is then treated with cold alcohol,
which will dissolve out the oily fat. The weight of the
residue left on evaporating the alcoholic solution, therefore, will represent the amount of OILY FAT in the serum;
and the differ.ence between  this and the weight of the
whole fatty matter shows the quantity of SOLID OR CRYSTALLINE FATTY MATTER in the same serum. The proportion of each of these, which is contained in 1000 parts of
blood, may then be calculated as follows:r Wt. of solid 1        Weight of 1  Total solid    r Fatty mat- 
residue of.  -    fatty        from 500     J ter in 500
serum    [        matter       gS. of        grs. of
L employed. J    Lobtained. J    L serum. J   L serum.  J
For the Oily Fat.
( Wt. of oily    Wt. of serum      Proportion of oily)
500:   fat in 500:  in 1000 parts:  fat in 1000 partsof 
grs. of serum.     of blood.             blood.
For the Crystalline Fatty Matter.
Wt. of crystal-    Wt. of serum)   Proportion of crys-)
500: line fat in 500::  in 1000 parts: talline fat in 1000
grs. of serum. J    of blood.        parts of blood.
547. The residue which proved insoluble in the ether
(545), is now to be warmed in order to expel any traces
of ether that may still be present, and then treated with
water which is gradually heated to boiling; this will
coagulate the albumen, thus rendering it insoluble, while
the extractive matters are dissolved out (519). The mnixture is then filtered through a dried and weighed filter,
and the insoluble residue of albumen washed on the filter
with hot water, until a drop of the filtered liquid causes
* The flask should be fitted with a cork carrying a glass tube about
three feet long and a quarter of an inch in diameter, to diminish the
loss of ether by evaporation.




QUANTITATIVE ANALYSIS OF BLOOD.   203
no precipitate, or merely a very slight opalescence, when
tested with a solution of nitrate of silver.
548. The albumen, thus freed from  extractive and
soluble saline matters, is to be dried and weighed; but
as some traces of'inorganic matter are always associated
with the albumen, the dry mass is to be incinerated, and
the weight of the ash deducted from it; when the diffrence will represent the amount of pure ALBUMEN in the
serum. The proportion in 1000 parts of blood may then
be calculated thus:IWt. of solid    r Weight of     r Total solid 1  r Albumen j
residue of    albumen        firom 500     ill 500
serum:   obtained. [:    grs. of:  grs. of
employed              J        erm.       serum. J
f Wt. of albu-    Wt. of serum )   Proportion of albu500: men in 500 grs.:: in 1000 parts:  men in 1000 parts
of serum.        of blood         of blood.
549. The aqueous solution filtered fiom the albumen
(517), containing the extractive matters and soluble salts,
is now to be evaporated to dryness in a capsule of known
weight, on a water-bath, and weighed. The dry residue
is then treated with alcohol, which should be poured off
and renewed as long as anything continues to be dissolved
by it. The alcoholic solution is evaporated to dryness
on a water-bath, and weighed; it is then incinerated, and
the weight of the ash is deducted from  that of the dry
mass previous to incineration. The number thus obtained
represents the amount of ALCOHOL EXTRACTIVE in 500 grs.
of serum, which may be reduced to the proportion in 1000
parts of blood by a calculation similar to the above.
550. The portion of the dry residue which proved insoluble in alcohol (549), is now to be dried, weighed, and
ignited; the weight of the ash being deducted from that
of the dry mass previous to ignition. This will give the
weight of the WATER EXTRACTIVE in 500 grs. of serum;
from which the quantity in 1000 parts of blood may be
estimated as in the former cases:W t. of water) { Wt. of serum {   Proportion of water
500: extract. in 500:: in 1000 parts I    extract. in 1000
grs. of serum. )  of blood       parts of blood.
551. We shall now have estimated the proportion of




2)04   QUANTITATIVE ANALYSIS OF BLOOD.
water and of all the solid constituents, with the exception
of the CORPUSCLES. The proportion of these is known by
deducting the sum of the several solid matters, the weights
of which are already determined (including everything
but the corpuscles), from the weight of the whole solid
matter contained in 1000 parts of blood (539), the difference representing the proportion of corpuscles present
in 1000 parts of the fluid.
552. The results of the analysis may then be recorded
as follows, and should, when added together, amount to
a fraction less than 100.
Water
Corpuscles
Albumen.
Fibrin
Alcohol extractive.
Water extractive
Oily fats.
Crystalline or solid fats
Fixed saline matter
SECTION IV.
Quantitative Analysis of Coagulated Blood, including the estimation of the water, corpuscles, albumen, fibrin, alcohol
extractive, water extractive, oilyfats, crystalline or solidfats,
and fixed saline matters.
553. About ten or twelve ounces of blood having been
collected in a beaker, or other rather tall vessel of known
weight, it is to be covered over to prevent evaporation,
and set aside in a cool place for about twenty-four hours,
when it will be found to have separated into a firm clot
and clear serum. The weight of the whole blood is to
be accurately determined either before or after coagulation. Three or four fluidrachms of the clear serum
are first drawn off with a pipette, weighed in a platinum
or porcelain crucible of known weight, evaporated to
dryness on a chloride of calcium bath, and the weight of
the dry residue ascertained. The loss of weight during
evaporation representing the water, we thus determine




QUANTITATIVE ANALYSIS OF BLOOD.   205
the relative proportions of SOLID MATTER AND WATER IN
THE SERUM.
554. the dry residue of the serum (553) is now to be
incinerated, until the ash becomes white or gray; and
the latter is then weighed. The proportion of FIXED
SALINE MATTER OF THE SERUM is thus ascertained.
555. The greater part of the remaining clear serum is
now to be carefully poured off from the coagulum, and
retained for further examination (565). The last portions of the liquid are to be removed by means of a fine
pipette, or by sucking it up with little rolls of bibulous
paper (522), carefully avoiding the removal of any portions of the clot.
556. The coagulum, thus separated as completely as
possible from the serum, is now to be divided vertically
into two portions of exactly equal weight (523), each of
which will then contain one-half of the fibrin and corpuscles present in the quantity of blood operated on,
together with a certain amount of serum. These two
equal portions of clot we will distinguish as A and B.
557. Tr-eatment of the portion of clot A.-This portion of
the clot is to be cut with a sharp knife into fine slices,
carefully avoiding any loss. These are then tied up in
a piece of fine muslin, and washed, until they become
quite colorless, when it may be concluded that the whole
of the corpuscles and serum has been washed out. The
fibrin is now dried on a chloride of calcium bath at a
temperature of about 230~, and weighed. It still, however, contains traces of earthy salts, the quantity of which
is known by incinerating the dry fibrin, and deducting
from it the weight of the ash. The loss of weight during
incineration represents the quantity of fibrin contained
in one half the clot, and this, when multiplied by two,
gives the proportion of FIBRIN in the quantity of blood
employed.
- 568. Treatment of the portion of clot B.-This half of the
clot is to be weighed in a capsule of known weight, and
evaporated to dryness on a chloride of calcium bath.
The residue is now weighed, and the loss of weight
during evaporation will show the amount of water present in half the clot; which, when multiplied by two,
18




206   QUANTITATIVE ANALYSIS OF BLOOD.
gives the quantity of WATER CONTAINED IN THE ENTIRE
CLOT; while the weight of the dry residue, also multiplie~] by two, represents the amount of SOLID MATTER
PRESENT IN THE ENTIRE CLOT.
The dry residue of B is to be retained for subsequent
incineration (563).
559. Having thus determined the weight of the whole
solid matter of the clot, which consists of fibrin and corpuscles, together with the solids contained in the portion
of serum with which the clot is saturated; we now have
to calculate how much of the weight is due to the solids
of the serum. Assuming that the whole of the water
present in the clot is due to the serum, and knowing the
relative proportions of water and solid matter in the
serum (553); knowing also the quantity of water present
in the entire clot (558); the amount of solid matters in
the clot which belong to the serum may be calculated in
the following manner:Wt.ofwater ] [ Wt. of solid 1  ( Wt. of  Wt. of solid
in quantity   matter in     water      matters of sei of serum m:'  quantityof   in entire  i rum contained'
evaporated.      serum evap. I  clot.  in the entire
l         J   L        J                   clot.  J
560. The weight of solid matters of the serum thus
found to be present in the clot, is to be deducted from
the weight of the entire solid matter of the clot (558),
when the difference will represent the weight of the
fibrin and corpuscles; the weight of the fibrin, however,
having been already ascertained by a separate experiment (557), we have merely to deduct that amount, in
order to determine the proportion of CORPUSCLES in the
quantity of blood employed in the analysis.
561. Now, since the blood may be said to consist
wholly of fibrin, corpuscles and serum; and knowing, as
we do (557, 560), the weight of the fibrin and corpuscles,
we can, by deducting the combined weights of those two
substances from the weight of the entire blood, learn the
proportion of SERUM in the quantity of blood operated
u pon.
562. But we have before determined the relative proportions of solid matter and water in the serum (553); so




QUANTITATIVE ANALYSIS OF BLOOD.   207
that assuming that the whole water of the blood is due
to the serum, we can, from the quantity of serum obtained
in paragraph 561; estimate the proportion of WAT'A in
the blood, thus:f Wt. of      (Loss of wt. I   (Wt. of serum ]   Proportion'
serum    I   during      1 in quantity I  I of water in I
( which was: J evapora- i::   of blood:   quantity of
I evaporated l    tion          used.   [  ]  blood
L to dryness. J  L (water). J   L       J  L  used.
563. The dry residue of the portion of the clot B (558),
is now to be incinerated. The weight of the ash thus
obtained, multiplied by two, will give the amount of the
inorganic salts contained in the clot. A certain portion
of this weight, however, is due to the salts of the serum
which was contained in the clot, the amount of which
may be learnt by the following calculation, since we have
before determined the relative proportions of solid matter
and inorganic ash in the serum (553, 554).
(Wt. of solid mat- I ( Wt. of ash I   (Wt. of solid I   W. of ash 7
ter in quantity |   derived   I   matters     derived
g of serum evapo- ~:{ from same,::  of serum  I:  from the
I rated to dry- I I quantity   I    in the   j j serum in
L    ness.     J Iof serum. J   L   clot.  J  L the clot. J
By deducting this number from the weight of the ash of
the whole clot, we ascertain the amount of inorganic saline matter derived from the fibrin and corpuscles.
564. In order to determine the whole amount of fixed
salts in the blood, we must now reckon how much the
whole of the serum contains. -This is done as follows:( Weight of 1  fWt. of ash     Wt. of se-    W t. of fixed 
serum evapo-    from sae    rum in        salts in
rated to      quantity                    the whole  F
[ dryness.  J  L of serum. J   i blood. J      serum.  J
By adding together the ash of the serum thus obtained,
and that derived from the fibrin and corpuscles (563), we
ascertain the proportion of FIXED SALINE MATTER in the
quantity of blood employed in the analysis.
565. Estimation of the albumen, extractives, and fatty matters. —Five hundred grains of the clear serum (555), are
to be weighed out in a platinum or porcelain evaporating
basin,and evaporated to dryness on a water bath. The residue is then treated as described in paragraphs 545-550.




'208    QUANTITATIVE ANALYSIS OF BLOOD.
566. The result of the analysis may then be summed
up as follows; and if the experiments have been conducted
with. care, the numbers will, when added together, coincide very nearly with the whole quantity of blood employed in the analysis.
Water
Corpuscles
Albumen
Fibrin
Alcohol extractive.
Water extractive
Oily fats.
Crystalline or solid fats.
Fixed saline matters
567. In order to reduce these several amounts to the
proportion contained in 1000 parts of the blood, the following calculation must be made in each case:Wt. of          Wt. of each    Proportion of that conblood: 1000:: constituent    stituent in 1000 parts
used.)          obtained.        of blood.
The several quantities thus obtained should, when added
together, amount to a fraction less than one thousand.
SECTION V.
Average Composition of Healthy Blood.
568. The following analysis will serve to show the
usual composition of healthy blood in 1000 parts.




QUANTITATIVE ANALYSIS OF BLOOD.  209
569. Analysis I.  Healthy Venous Blood. (Dumas.)
10 C   Fibrinl.....           3
130 Clot.     Globules { Hmatin2
Albuminous  matter... 125 
f Water.790
Albumen.......   70
Oxygen.
Nitrogen
Carbonic acid
Extractive matter.
Phosphorized fat.
Cholesterin.....
870 Serum Serolin., Oleic and margaric acids.
Chlorides of sodium and potassium.
Muriate of ammonia                         10
Carbonate of soda, lime, and magnesia
Phosphates of soda, lime, and magnesia
Sulphate of potash...
Lactate of soda.
Salts of the fatty acids..
L Yellow coloring matter..
1000                                               1000
570. Analysis Ii.  (Simon.)
Water..795-278
Fibrin........  2104
Fat.                                           2 346
Albumen.                                      76-600
Globulin........ 103022
Hlenatin.6 209
Extractive matter and salts.... 12012
571. Analyses III and IV.  (Becquerel and Rodier.)
Showing the mean composition of Male and Female Blood.
Male.     Female.
Density of defibrinated blood. 1060'00   4057'50
Density of serum...         1028'00'1027 40
Water.... 77900  791'10
Fibrin...                            2'20  2'20
Fatty matters.              160        1'62
Serolin....                     02        0'02
Phospbated fat..   049          0'46
Cholesterin..                  009         0'09
Saponified fat..   100          1.04
Albumen......  6940              70'50
Blood-corpuscles.... 141'10      127-20
Extractive matters and salts.    680        7 40
Chloride of sodium..         3.10       3'90
Other soluble salts..   2'50        2-90
Earthy phosphates..   033         0.35
Iron \.'...   057         0'54
~''   1 ~q-x-''




210                   MORBID BLOOD.
572. Analysis V. (Lehinan.)
Bloodcorpuscles.  Liqnor-sanguinis.
Water...           688-00    902'90
Solid constituents.             312'00         97'10
Specific gravity.... 10885      1'021
Hsematin.                     1675 Fibrin    4'05
Hsemato-crystallin.  241'07 Albumen 78'84
Cell-membranes                      41'15
Fat..                              231            1'72
Extractive matter.                   2'60           3-94
Mineral substances (exclusive of
Iron)......    812                8.55
Chlorine.                        1686          3-644
Sulphuric acid.... 066        0115
Phosphoric acid.. 1'134            0'191
Potassium..                     3-328         0.323
odium....    1052    3'341
Oxygen....    0667                      0 403
Phosphate of lime....   0114            0'311
Phosphate of magnesia.         0'073         0'222
573. Analysis VL. (Enderlin.)
Showing the Conmposition of the Ash of Human Blood.
Tribasic phosphate of soda (3NaO,P05). 22-100 1
Chloride of sodium                     54-769   83 746. Soluble
Chloride of potassium.         4-416 [          salts.
Sulphate of potash.                    2.461 J
Phosphate of lime                        3-6....36 
Phosphate of magnesia...  0'769  15'175    saInltble
Peroxide of iron and phosphate of iron. 10770s.
98'921
Recent analyses have proved that, as would be expected,
the quanitative composition of the blood varies with the
part of the circulation from which it is drawn.
CHAPTER III.
MOR;BID BLOOD.
574. THE chemistry of the blood in its pathological
conditions, has, until within the last few years, occupied
very little attention from the chemist or physician; the




MORBID BLOOD.                  211
consequence of which has been, that much ignorance has
always prevailed, and, it is to be feared, still prevails,
among the great mass of the profession, respecting this
important and interesting subject of of inquiry. It is not
unreasonable to anticipate that the fresh knowledge which
we are now almost daily acquiring in this and other
kindred branches of physiological and pathological chemistry, will gradually lead to highly important and beneficial practical results, in the more enlightened treatment
of disease, and the more ready mitigation of suffering.
575. The variations which are found to occur in the
chemical composition of morbid blood may be divided
into two classes:1st. Those in which, so far as we are aware, no abnormal matter, not contained in healthy blood, is present;
but in which one or more of the normal constituents
of healthy blood exists in a greater or less proportion than in the healthy fluid.
2d. Those in which we can detect.the presence of one
or more abnormal matters which are not found in
healthy blood.
576. To the first of these classes belong those cases in
which we find an excess or deficiency of water, corpuscles, albumen, fibrin, fatty matters, cholesterin, urea, uric
acid, or inorganic salts; and to the second, those in which
either sugar, biliary matter, pus, entozoa, or other abnormal matter, can be detected. I will briefly notice each
of these morbid conditions of the blood, together with
the mode of examination, whether chemical or microscopic, which will be found most readily applicable to
each.
CLASS I. -Morbid Blood in which no abnormal matter is
present.
SECTION I.
Blood containing an excess or deficiency of Wtater.
577. The proportion of water even in healthy blood
appears to vary considerably, so that it is difficult to-say




212               MORBID BLOOD.
what may be considered as the normal amount. The
usual average, however, contained in human blood, seems
to be from 790 to 800 in 1000 parts.
578. In some forms of disease, as, for example, ansemia
and chlorosis, the proportion of water is usually much
greater, and has been known to amount to upwards of
900 parts in 1000. In certain other pathological conditions, on the contrary, the blood is found to contain considerably less water than is present in the healthy fluid;
in cholera, for instance, where the blood is so rich in solid
matter as almost to resemble jelly in appearance, it has
been known to contain not more than 480 parts of water
in 1000.
579. The proportion of water present in any specimen
of blood may readily be ascertained, by evaporating a
known weight of the fluid in a weighed or counterpoised
capsule, on a chloride of calcium bath, heated to about
220~ or 2300, until it ceases to lose weight. The loss of
weight during the evaporation will then represent the
proportion of water in the quantity of blood employed,
which may be reduced to 1000 parts, as follows:Weight of                             Proport   f
Loss of weight         wate in 1000 l
b~    blood           rn::1000  water ill 1  o1 
evaporated.    during evaporation. J *   parts of blood.
SECTION II.
Blood containing an excess or deficiency of Corpuscles.
580. The average proportion of corpuscles contained
in healthy human blood appears to be from 120 to 130
parts in 1000. In disease, especially in some forms of
fever, it sometimes increases considerably, and has been
known to amount to 185 parts in 1000; while in anaemia,
and certain other affections long known as being attended
with great poorness of blood, the proportion of corpuscles
frequently does not amout to more than 60 or 70, and has
been known to be as low as 21, in 1000 parts.
581. The direct determination of the weight of the
corpuscles is a matter of considerable difficulty, so that
they are generally estimated by deducting the combined
weights of the water, fibrin, and solid matters of the




MORBID BLOOD.                 213
serum, which are easily determined experimentally, from
that of the entire blood, in the manner described in paragraphs 518, 527, &c.
582. According to Figuier, their weight may be determined with considerable accuracy by mixing the blood,
previously defibrinated by agitation with fragments of
lead (507), and weighed, with about eight times its bulk
of a saturated solution of sulphate of soda, filtering
through a filter of known weight, and washing the corpuscles of the filter with a little more of the saline solution (456). When most of the liquid has drained through,
the filter with its contents is dipped in boiling water, and
allowed to remain in it some little time, in order to dissolve out the salt; while the organic matter of the corpuscles is coagulated by the heat, and thus rendered
insoluble. The filter, with the corpuscles, is then dried
at 2120, weighed, and the weight of the dry filter, previously determined, being deducted, the difference will
represent the weight of the corpuscles contained in the
quantity of blood operated on.
583. The microscopic appearance of the corpuscles is
also not unfrequently found to vary under the influence
of disease, the modifications of form occurring occasionally in the living body, but more frequently after death.
Most of these changes are due to the phenomena of en.
dosmosis or exosmosis already referred to (456). Thus
they are sometimes met with having a more or less globular form, owing to the entrance of fluid less dense than
the serum  of healthy blood; at other times they are
found to have a wrinkled or indented outline, similar to
that which the healthy corpuscle assumes when placed
in contact with strong saline solutions of high specific
gravity. (See Fig. 65.)
584. In examining the blood corpuscles under the microscope with a view to detecting any abnormal appearance as a consequence of disease, it must be borne in
mind that these and other analogous changes in the form
of the corpuscle are artificially induced by the action of
water or other liquids with which they may have been
allowed to come in contact; such contact should therefore
be carefully avoided. The wrinkled appearance is sorne



214               MORBID BLOOD.
times caused also by the concentration of the serous fluid,
owing to spontaneous evaporation (456).
SECTION III.
Blood containing an excess or deficiency of Albumen.
585. The average proportion of albumen in healthy
blood appears to lie between 70 and 75 parts in 1000;
while in disease it is occasionally (as in cholera) as high
as 131, and (as in Bright's disease) as low as 55 parts in
1000.
586. The amount of albumen in any specimen of blood
may be ascertained in the manner described in paragraph
547; or a weighed portion of serum may be carefully
neutralized with dilute hydrochloric acid, diluted with
an equal bulk of water, and boiled for about a quarter
of an hour. The coagulum of albumen is then separated
by filtration, dried at 2120, and treated with hot ether to
remove the fat (545), and weighed before and after incineration; the difference between the two weighings being
the weight of albumen in the quantity of serum used (548).
587. The quantitative estimation of the other constituents of the blood may, if necessary, be conducted as in
the case of healthy blood (503, &c.).
SECTION IV.
Blood containing an excess or deficiency of Fibrin.
588. Healthy human blood usually contains from two
to three parts of fibrin in 1000; while in disease it has
been found to vary from a mere trace, to upwards of ten
parts in 1000; a considerable increase in the amount
being usually found in most forms of inflammatory disease.
589. The peculiar appearance frequently to be seen
after coagulation, in blood taken from the body during
certain pathological conditions, long known as the buffy
coat, is caused by the upper portion of the clot being
composed almost entirely of fibrin, or of some modification of protein closely allied to it, unmixed with the red
corpuscles. This may be owing either to the blood



M'ORBID BLOOD.                 215
corpuscles subsiding in the liquid more rapidly than in
ordinary blood, or to the fibrin, coagulating more slowly;
in either case the upper portion of the coagulated fibrin
would be more or less free from the corpuscles to which
the red color of the ordinary clot is due. The blood in
which the buffy coat is found to occur is, in most cases,
rather rich in fibrin, and it was formerly regarded as a
sure sign of inflammation; an opinion which has since
been proved to be altogether erroneous (452).
590. The proportion of fibrin may be readily determined either in coagulated or freshly drawn blood, in the
manner already described. For freshly drawn blood, see
paragraph 510, &c., and for coagulated blood, see paragraph
524, &e.
The quantitative estimation of the other ingredients
may also, if necessary, be conducted in the same manner
as in healthy blood (503, &c.).
SECTION V.
Blood containing an Excess of Fatty Matter.
591. The average amount of fat in healthy blood
appears to be something more than two parts in a thousand. The whole of the oily fat probably exists in combination with potash or soda, forming a kind of soap; so
that in the healthy fluid no oil globules can be detected.
592. In certain pathological conditions, we occasionally
meet with blood containing a considerable quantity of
free fat, which is held in suspension, in the form of minute glo-        Fig. 67.
bules, in the serum, giving that    o      -       o
fluid a more or less opaque or      7 ( ~    o~?    emilky appearance. In this form                 0'
of blood, which, from its peculiar    0 O 
appearance, has been called milky o, %c OQ
blood, may be seen, with the help,11oo   ~ ~.O,
of the microscope, innumerable  L_J~ ~i q~: ~  f' —
fat globules, which may be readily    Fat in Blood.
distinguished by their bright centres, and black, well-defined outlines (Fig. 67).  They
may be separated by agitating the serum with a little
ether, which will readily dissolve them.




216              MORBID BLOOD.
593. The amount of fat in any specimen of blood may
be determined by evaporating to dryness a known weight
of the fluid, pounding the dry residue, and boiling it with
successive small quantities of ether (545). The ethereal
solution of the fat thus obtained is evaporated to dryness
in a counterpoised capsule, and weighed; its weight
representing the proportion of fat in the quantity of blood
employed.
594. The quantitative determination of the other constituents of the blood may, if required, be effected in the
same manner as in the healthy fluid (503, &c.).
SECTION VI.
Blood containing an Excess of Cholesterin.
595. Minute traces of cholesterin appear to be always
present in healthy blood, though some observers have
failed in their endeavors to detect it. The amount, however, in certain forms of disease not unfrequently rises
as high as 0'15 to 0'20 in 1000 parts; and in one case of
so-called milky blood, Lecanu found not less than 108 in
1000.
596. When an excess of cholesterin is suspected to'be
present in any specimen of blood, it may be separated
and estimated with tolerable accuracy in the following
manner. A known weight of the blood is evaporated to
dryness on a water-bath,
Fig. 68.          and the dry residue, after.......being  reduced  to fine
_-_  ______powder in a mortar, is
digested for a few hours
in ethler, the solvent action being assisted  by
/r~~~ 1           Siroccasional boiling (545).,____, In this way the choles_-____==___             terin, together with the
Cholesterin.       other fatty matters, is dissolved, and may be obtained by evaporating the ethereal solution on a waterbath. The residue is then deprived of the oily portion
of the fat, by digestion with cold alcohol, which leaves




MORBID  BLOOD.                    217
undissolved the cholesterin, with the other solid fatty
matters; the crystalline scales of cholesterin (Fig. 68),
which ate easily distinguishable from the rest, may then
be, for the most part, mechanically separated with the
point of a knife. Their weight may then, after drying,
be ascertained if necessary.
597. The quantitative estimation of the other constituents may be conducted as in the case of healthy blood
(503, &c.).
SECTION VII.
Blood containing an Excess of Urea.
598. Minute traces of urea are probably always present
in healthy blood (484), though the amount is so small as
to be incapable of determination, unless considerable
quantities of blood are used. In some forms of disease,
however, especially in Bright's disease, cholera,* and
certain other pathological conditions, in which the functions of the urinary organs are to any serious extent
interfered with, the amount of urea is found to increase
considerably, and may frequently be met with in a sufficiently large quantity to be weighed.
599. The detection and estimation of urea in the blood
may be conducted in the following manner. A known
weight of serum is first evaporated to dryness on a waterbath, at a very gentle heat, a precaution  necessary to be
observed, since a temperature of 212~, long continued,
such as is required in this analysis, would probably cause
the decomposition of some portion of the urea.  The dry
residue is reduced to fine powder in a mortar, and treated
with distilled water, heated to about 200~, the quantity
of which may be about double the volume of the serum
employed in the experiment. The mixture is allowed to
digest for about half an hour at 200~, after which it may
be filtered from the insoluble residue of albumen,t which
* It has been stated that, in cholera, a peculiar ferment is present
in the blood, which very rapidly converts the urea into carbonate of
ammonia (11).
t A more delicate process consists in drying the serum in vacuo
over sulphuric acid, and extracting the powdered residue with alcohol,
which dissolves the urea.
19




218               MORBID BLOOD.
latter must be washed while on the filter with a little
more warm water. The filtered aqueous solution is now
evaporated to dryness, and the residue digested with a
little absolute alcohol, at a very gentle heat, which may
be continued for about half an hour; a little fresh alcohol
being added occasionally, to replace that lost by evaporatiou. The mixture is then filtered; the clear alcoholic
solution is evaporated to dryness, and the residue treated
with a little lukewarm distilled water, which will then
contain merely the urea, together with a small quantity
of extractive matter.
600. The aqueous solution thus obtained is evaporated
at a very gentle heat, to the consistence of a syrup, and
then mixed with a few drops of pure and colorless nitric
acid (16, 181), the mixture being kept cool by immersing
the glass containing it in a little cold water, or, still
better, in a freezing mixture composed of equal weights
of crystallized nitrate of ammonia and water. If urea is
present, delicate crystalline plates of nitrate of urea
(C0I24N,O2,HO,NOs), will gradually appear (Fig. 2), which,
if in sufficient quantity, may be dried by gentle pressure
between folds of filtering paper, and weighed. From
the weight thus obtained, that of the urea in the quantity
of serum employed may be calculated as follows:Atomic wt. of nitrate  Atomic wt. Wt. of nitrate  Wt. of urea in quantity of
of urea.    of urea.    obtained.   serum employed.
123:   60::    a:           x
601. If no appearance of crystallization can be detected
with the naked eye, a drop of the acid liquid, cooled by
means of a freezing mixture, is to be examined under
the microscope, by which means very small traces of urea
may be detected (181).
602. The quantitative determination of the other con
stituents may be effected with a fresh portion of the blood
in the same manner as in the healthy fluid (503, &c.).




MORBID BLOOD.                  219
SECTION VIII.
Blood containing an Excess or Deficiency of Inorganic Saline
M21atter.
603. The average proportion of inorganic saline matter
in healthy blood, appears to be about seven parts in 1000.
In scurvy, and some other pathological conditions, their
amount has been found to increase, and has been known
to amount to as much as eleven parts in 1000. In some
other diseases, on the contrary, the amount falls below the
healthy average.
The proportion of fixed saline matter in any specimen
of morbid blood, may be determined as in the case of the
healthy fluid-viz., by evaporating to dryness a known
weight, and incinerating the residue until the ash becomes
nearly colorless. The weight of the ash thus obtained
represents the amount of salts in the quantity of blood
employed.*
60-. The presence of uric acid (urate of soda) in the
blood of gouty patients, may be shown by evaporating a
little of the fluid to dryness on a water-bath, and, after
washing the dry residue with alcohol, adding a slight
excess of dilute hydrochloric or acetic acid to a strong
aqueous solution of the extract which proved insoluble
in the alcohol. After standing a day or two, minute
crystals of uric acid, similar to those formed in the urine,
are gradually deposited, and may be identified under the
microscope (186, 194), or by their behavior when treated
with nitric acid and ammonia (23). Even in healthy
blood, minute traces of uric acid may generally be detected..
A simpler test devised by Dr. Garrod, consists in treating the serum with acetic acid in a watch-glass in which
a fine thread is placed. After an hour or two, the thread
is examined by the microscope, when crystals of uric acid
are discernible upon it.
* See note to paragraph 63.




$2%0              MORBID BLOOD.
CLAss II.- Morbid B lood c on taining someA briormcal Ingredient.
SECTION IX.
Blood containing Sugar (e2/1,,O4O4).
605. The blood of patients sufebring from diabetes,
appears most commonly to contain a very sensible amount
of sugar.* This may usually be detected in the following
man ner:606. The portion of serum  intended for examination
is first evaporated to dryness, either in vacuo over sulphuric acid, or at a very gentle heat on a water-bath.
The dry residue is then reduced to tolerably fine powder,
and treated with a small quantity of boiling water, which
will have the effiect of coagulating the albumen, and
dissolving out the sugar, together with the extractive
matters and soluble salts.  The mixture is then filtered,
and the clear liquid examined for sugar, by means of
Trommer's test, which may be thus applied:607. The liquid is treated with a drop or two of a
solution of sulphate of copper, and then supersaturated
with potash (123), the excess of which will probably, if
sugar is present, redissolve the blue precipitate of hydrated
oxide of copper at first thrown down. The mixture may
now be gently boiled for a few minutes, when, if sugar
is present, an orange-brown or oehre-colored precipitate
of suboxide of copper will be thrown down; while if
no sugar is contained in the mixture, the precipitate will
be nearly black (124).
608. It is always more satisfactory, when practicable,
even when Trommer's test affords tolerably decided indications of sugar, to confirm the result by applying also
Bbttger's test (127), the fermentation test (128), and
examining under the microscope for the torula (132);
since certain other organic matters besides sugar give rise
to the formation of the suboxide.
609. When, after having proved the presence of sugar
* See note to paragraph 484.




MORBIL) BLOOD.                221
in the blood, it is required to determine its amount, the
following method of insulating it is, perhaps, the best,
though the results must not be regarded as by any means
exact, but merely as an approximation to the truth. The
fermentation process (128) cannot be here applied, since
traces of carbonic acid may be evolved by some of the
other constituents of the blood, when no sugar is present.
610. A known weight of serum is evaporated to
dryness, either in vacuo over sulphuric acid, or at a very
gentle heat on a water-bath. The dry residue is then
finely comminuted and treated with boiling water, in
which it may be allowed to digest for three or four hours,
in order to insure the solution of the whole of the soluble
matter. The aqueous solution is separated from the
albumen by filtration, and evaporated to dryness as
before. The dry residue is now digested with alcohol,
which leaves undissolved portions of the saline and
extractive matters. The alcoholic solution is mixed with
a little alcoholic solution of potash, and set aside for
twenty-four hours, when a crystalline compound of sugar
and potash will be-deposited. The alcoholic solution may
now be poured or filtered off, and the crystalline compound dissolved in water with a view to the determination of the quantity of sugar by means of the standard
alkaline solution of copper (352).
When the freshly drawn blood can be obtained, the
following process recommended by Figuier may be
adopted. About six ounces of blood are defibrinated by
stirring (477), and mixed with three volumes of a saturated solution of sulphate of soda. The blood globules
are then filtered off, and the filtrate mixed with two
volumes of alcohol, to coagulate the albumen and precipitate the sulphate of soda. These having been filtered
off; the solution is evaporated to dryness on the waterbath, the residue extracted with water, and the sugar
determined by the alkaline copper solutiou (352).
611. The quantitative determination of the other constituents of blood containing sugar may be effected in
the same manner as in the case of healthy blood, the
weight of the sugar being deducted fromi the extrgctive
matter (503, &c.).




222               MORBID BLOOD.
SECTION X.
Blood containing Biliary Matter.
612. In jaundice, and some other affections in which
the functions of the liver are interfered with, an accumulation of biliary matter is found to take place in the
blood, giving the serum a more or less decided saffron
or orange-brown color, which is due to the peculiar coloring matter of the bile, called biliphcein (cholepyrrhin).
613. The presence of bile in the blood may be detected
by adding to a little of the clear serum a few drops of
nitric acid, which will throw down the albumen; the precipitate having, if biliary matter (biliphcein) is present, a
decided greenish tint, while in healthy serum it would
be white, or very nearly so.
614. If so small a quantity of bile is present as to fail
in producing a perceptibly green color with nitric acid,
a little of the suspected serum may be first concentrated
by evaporation at a temperature not exceeding 120~ or
130~, and then exhausted with alcohol or water, and the
solution tested in the manner already described in the
case of urine (149-152).
615. We have at present no means of estimating the
quantity of biliary matter contained in blood, though the
depth of color of the serum furnishes some indication of
the relative amount present. The quantitative determination of the other constituents of the blood may be
made in the same manner as in the analysis of the healthy
fluid (503, &c.).
SECTION XI.
Blood containing Pus.
616. The existence of pus in morbid blood is probably
by no means a rare occurrence, especially in diseases
which are attended with suppuration. Its detection,
however, is far from easy, since we possess no;characteristic chemical test by which it may-be distinguished from
the ordinary constituents of the blood;- and in microscopic appearance, the pus granules very closely resemble
the colorless corpuscles which are always present in the
blood (464). The pus granules are in general somewhat
larger than the white corpuscles of the blood, and when




MORBID BLOOD.                 223
treated with dilute acetic acid, develop internal nuclei,
which are usually from three to five in number, and more
distinct than those in the white corpuscles of the blood.
The pus granules, when present in blood, appear to have
a tendency to adhere together in groups of five or six;
while the colorless corpuscles of the blood always float
detached from each other.
617. According to Heller, the granules of pus, when
mixed with blood, subside much more slowly than the
blood-corpuscles; so that when present, they may always
be found in the uppermost layer of the coagulum.*  He
recommends a thin slice to be taken from the upper surface of the latter, which, after being mixed with a little
distilled water, should be filtered through muslin, in order
to separate the fibrin. The blood corpuscles are for the
most part dissolved by the action of the water (458); and
after allowing the filtered liquid to stand a short -time in
a tall glass, the pus granules will be found at the bottom
of the liquid, and may be detected under the microscope.
618. The action of ammonia upon pus has been proposed by Donne as a test for its presence in the blood.
When blood, free from pus, is mixed with ammonia, it
becomes clear; while if pus is present in any considerable quantity, the liquid becomes more or less gelatinous.
If the amount of pus present is small, stringy flocculi only
are formed, which subside to the bottom of the liquid.
SECTION XII.
Blood containing Animalcules.
619. Instances have occasionally been observed, in
which minute thread-like animalcules have been present
in considerable numbers in the blood. Those described
by Dr. Goodfellow, which he detected in the blood of a patient suffering from fever, measured from m',th to 3 I th
of an inch in length, and from  ~      -0~th to 0o-uth of
an inch in diameter. The only method of detecting such
entozoa in the blood, is to examine it carefully under the
microscope, with as high a magnifying power as the
observer has at his command.
* This remark also applies to the colorless corpuscles.




PART IV.
lMILK, BILE, MUCUS, PUS, BONE, &c.
CHAPTER I.
MILK.
SECTION I.
General Characters of Millke
620. MILK, as is well known, is a watery liquid, having
in solution a certain amount of casein, sugar of milk, or
lactine and extractive matter, together with several inorganic salts, and holding in suspension myriads of extremely minute globules of fatty matter, plainly visible
through the microscope, which give the fluid its peculiar
white and opaque appearance. It has a pleasant and
rather sweetish taste, and a slight agreeable smell, especially while, warm. The specific gravity of milk varies
considerably; that of woman being sometimes as low as
1020 (the average being 1032),. while that of the sheep
is as high as 1041.
621. Fresh milk is almost invariably slightly alkaline
to test paper, but on exposure to the air, especially in
warm weather, it rapidly becomes acid, owing to the conversion of the sugar of milk into lactic acid (21O, C,2
Hi0,,O), under the influence of the casein, which acts as
a ferment (630). If the milk has been long retained in
the mammary glands, this change occasionally takes
place before being drawn; and in some morbid conditions also, the milk is found to have an acid reaction
even when freshly drawn.




MrILK.                      225
622. When allowed to stand for a few hours, the fatty
globules, which have a somewhat lower specific gravity
than the fluid portion of the milk, gradually rise to the
surface, carrying with them a portion of the caseous matter, forming a layer of cream, which is more or less thick
and copious in proportion to the richness of the milk.*
623. If a little acetic or lactic acid, rennet, or even
sour milk, be added to hot milk, the casein of the latter
is precipitated in the coagulated form; and the same
effect is produced by warming milk or cream which has
been allowed to turn sour; the sourness being due to the
lactic acid, into which the sugar of milk has been converted. The solid and liquid portions into which the
milk is thus divided, are commonly called curds and
whey.
624. Before describing the mode of analyzing milk, I
will briefly notice the several constituents which we find
contained in it-viz., casein, sugar of milk, fat globules,
and saline matter.
SECTION II.
Casein.
625. Casein is one of the so-called protein compoundst
(472) peculiar to the milk, and constitutes the chief
source of nourishment to the young animal; for which
purpose it is admirably adapted, from the readiness with
which it appears capable of being converted into the
other bodies of the same class-viz., fibrin and albumen.
626. It may be obtained in a state of tolerable purity
by evaporating a quantity of milk to dryness on a waterbath, and boiling the dry residue in successive portions
of ether, in order to dissolve out the fat.  The residue
which remains insoluble in the ether is then dried, and
digested in water, which will dissolve the casein and
* According to Miller, fresh milk, when allowed to stand, first
undergoes a peculiar change, resulting in the dissolution of the membranes inclosing the fat globules, so that the proportion of fat which
can be extracted by ether continues to increase for some time after the
milk has been drawn.
t See note to 471.




226                     MILK.
other soluble matters of the milk. On adding alcohol to
the aqueous solution, a great part of the milk-sugar is
thrown down in the form of a precipitate, leaving the
casein in solution together with some milk-sugar and
soluble salts.
It may be obtained in a purer condition by adding a
little hydrochloric acid to skimmed milk, collecting the
curd upon a linen strainer, and washing it first with
water, then with water slightly acidified with hydrochloric acid, and finally with pure water. If it be then
heated to 110~ with a large volume of water, the greater
portion will dissolve slowly, and may be reprecipitated
from the filtered solution by neutralization with carbonate of ammonia. After washing with water, and warming, first with alcohol, and afterwards with ether to remove all fatty matter, the casein is as pure as it can be
obtained. It always leaves an ash of phosphate of lime
when burnt.
627. It is most probable that pure casein is insoluble,
or very sparingly soluble, in water, and owes its solubility in milk to the small quantity of alkali which is
present. WVhen dry, it closely resembles fibrin and
albumen in appearance (479), and its behavior with reagents is in most cases very similar; it differs from the
latter chiefly in not coagulating when heated; and it is
precipitated by acetic, and nearly all the acids, but redissolves in a considerable excess of most of them.  Its
solution in acetic acid is precipitated by dilute sulphuric
acid. The ferrocyanide and ferridcyanide of potassium
also cause precipitates in solutions of casein.
SECTION III.
Sugar of Milk and Lactine (C,241,,,O).
628. The sugar contained in milk may be prepared in
the following manner: The curd, including the greater
part of the casein and fat globules, is first separated by
the addition of a few drops of acid to hot milk, and the
remaining traces of those substances are then removed
by mixing a little well-beaten white-of-egg with the whey
when cold, and afterwards boiling the mixture.  The




MILK.                      227
whey thus clarified by the coagulating albumen of the
egg, is filtered from the precipitate by passing it through
muslin or calico; and the clear liquid may then be
evaporated to about one fourth or one fifth its bulk, and
set aside in a cool place for a few days. The sugar will
gradually separate from the liquid, in the form of minute
hard crystals, which adhere to the surface of the containing vessel. These may be purified by dissolving them
again in water, boiling the solution with animal charcoal,
and recrystallizing.
629. This variety of sugar is less sweet than that obtained either from the cane or the grape (114); it is also
harder and less soluble in water, requiring as much as
five or six times its weight of cold, and two and a half
times its weight of hot, water to dissolve it. When
mixed with a little hydrochloric or sulphuric acid, sugar
of milk gradually becomes converted into grape sugar
(C12EI,4014), and this change takes place more rapidly if
the solution is boiled.
630. Under the influence of the caseous matter of the
millk, this form of sugar gradually passes into lactic acid
(2HO, C,12ff,010), a change easily accounted for, since the
formula of the sugar is a multiple of that of the acid, one
equivalent of the former being broken up into two of the
latter.
C24H24024=2(2H O, CH0 0,0).
SECTION IV.
Fat Globules.
631. The minute globules which are held suspended
in milk, and to which the opacity
and whiteness of the fluid are due,       Fig. 69.
consist mainly of oily fat, which'
appears to be surrounded by a thin.     o o 
covering of insoluble matter difter-  o     o ~  ooo
ing in its properties from fat, and,%~  ot0 ~o
probably composed of one of the       3=:3o~.~. ~,,
protein compounds. It is for this  t,         o o
reason that the fat globules cannot    ~D ~o      e00
be removed from milk by agitation       Milk Globules.
with ether, unless potash be previously added to dissolve the men'mbranous envelopes.




228                       MILK.
632. The size of the globules in healthy milk varies
from a mere point to about W- voth
Fig. 70.        of an inch in diameter, the aver_   age size being rather more than
o0 JA MB)d" -  a~~~~ -4~th (Fig. 69).
6k;3. In  the  milk  which  is
Pod'i  secreted during the first few days..o   of lactation, called the colostrumn,'.~ ~'    and which is always much richer
in  quality  than  ordinary  milk,
we find in addition to the com~t )   <Q~ A   mon  milk  globules, numerous
Colostrum Corpuscles.    granular  corpuscles  of a  pale
yellowish color,and considerably
larger than  the others, their diameter varying  from
Io th to s,6th of an inch (Fig. 70).  Similar corpuscles
are also occasionally  present in milk secreted during
disease.  They appear to be almost peculiar to human
milk, being rarely met with in that of the cow and other
animals.
634. The fatty matter of milk consists for the most
part of a solid fat, called margarine (08,,1H10a401), mixed
with a liquid fat or oil, called oleine (C1lHla4012), together
with small quantities of butyrine and other fats. The
proportion in which these several fats are found mixed
in milk, varies considerably, being influenced by the
health and food of the individual, the seas6n of the year,
and other circumstances.  A  specimen of the fat contained in cow's milk, analyzed by Bromeis, containedMargarine..68
Oleine. 30
Butyric, caproic, and capric acids....  2
100*
* Heintz pronounces the margarine of butter to be a mixture of
stearine (C114H1,0012) and palmitine (C0o2H90,2). He has also obtained a new acid called butic or butinic acid (HO,C40H90,,) from butter,
as well as caprylic (HO,CGiH,sO3) and myristic (HO,C8,I28270s) acids.




MILK.                      229
SECTION V.
Saline Matters.
635. It is probable that the following salts are present
in milk, though an analysis of the ash will not, of course,
detect the organic and volatile compounds included in
the list, since they are either decomposed or volatilized
during the process of incineration: the chlorides of
potassium and sodium; the phosphates of potash, soda,
lime, and magnesia, with traces of phosphate of the peroxide of iron.
636. According to IHaidlen, the ash obtained by incinerating 1000 parts of cow's milk, consisted, in two
instances, of the following substances:I.  I.
Phosphate of lime. 2'31     3'44
Phosphate of magnesia. 0'42     0 64
Phosphate of peroxide of iron.. 007  0'07
Chloride of potassium.. 1'44    1'83
Chloride of sodium. 0.24     0'34
Soda.                           0-42 0'45
4'90    6-77
637. The presence of these several salts may be proved
by applying to a solution of the ash in water and hydrochloric acid, the tests mentioned in the chapters on the
urine and the blood (41, 490, &c.).
SECTION VI.
Composition of Human Milk.
638. In healthy human milk, the several constituents
which I have now briefly described, are not always present in the same relative proportions; various circumstances, as those of age, temperament, and food of the
mother, as well as the period of lactation, causing considerable variation in the composition of the secretion.
The following examples will serve to show to what extent
these variations usually occur.  The proportions are
calculated in 1000 parts of milk.
20




230                           MILK.
Analysis I   (Simon.)
Showing the mean of Fourteen Analyses mnade at d'ffereztperiodls, with
the Milk of the same Woman.
Water..883'6
Solid constituents.. 1164
Butter*..   25'3
Casein   34-3
Sugar of milk and extractive matters.              48'2
Fixed salts..                               2-3
Analyses II, III,  and -IV.  (Clemm.)
The fourth day   The ninth day   The twelfth day
after delivery.   after delivery.  after delivery.
Water               879 848         885-818         905-809
Solid constituents   120'152        114'182          94-191
Butter..     42 968          35 316          33'454
Casein'.        35'333          36'912          29'111
Sugar  of milk  )
and extractive   41'135         42'979          31'537
matters.    )
Salts..       2095           1.691           1'939
Analysis VII.   (Chevallier and Henri.)
Water..879 8
Solid constituents.. 120'2
Butter.                                             35.5
Casein.152
Sugar of milk.. 65'0
Salts                                                 4.5
The recent analyses of MM. Vernois and Alfred Becquerel give the following  as the composition of normal
human milk:
Water.. 889.08
Sugar.4364
Casein and extractive.39 24
Butter..26'66
Salts (ash).. 1.38
1000'00
Specific gravity, 1032'67.
* The portion of milk drawn at the commencement of a draught
(whether from a woman or a cow) is not so rich in butter as that
drawn at the conclusion.




MIL:K.                        231
SECTION VII.
Composition of the Milk of other Animals.
639. The proportion  of the several constituents  is
found to differ considerably in the milk of different
animals.*  The subjoined table, showing the composition
of the milk of a few of the more important domestic
animals, from the analyses of Chevallier and Henri, will
serve to illustrate this:
Cow.      Ass.    Goat.    Ewe.
Casein...    448        1.82     408       4'50
Butter...    3'13       0'11      332      4'20
Sugar of milk..    4'77      6'08      5 28     5'00
Saline matter.      060       0'34     0'52      0'68
Water...   87'02    91'65    86-80        85-62
100'00   100'00   100'00    100'00
639a. According to the analysis of Morin,t milk contains a considerable quantity of a substance resembling
gelatine, which he proposes to call galactine. Both this
substance and the caseine of milk possess a specific
power of emulsifying the fats, and he thus accounts for
the minute state of division of the fatty matter in milk.
It is also asserted that the coagulum  obtained by boiling
milk which has been curdled by acetic acid and filtered,
consists of albumen. The results of Morin's analysis of
cow's milk were:Casein....3614
Soda in combination with it.  048
Butter....                           1378
Albumen......  3'90
Sugar of Milk....     36'00
Galactine (gelatigenous matter)              3'82
Alcoholic extractive...,..  542
Phosphate of lime..                      2-56
Chloride of sodium.  0'56
Water..... 897'34
1000.00
* Schlossberger describes the milk of the carnivora as having
usually an acid reaction. The milk of stall-fed cows, mares, and ewes
kept on green food is also said to be frequently acid.
t Journ. of Pharm. (3), xxv. 71.




232    QUANTITATIVE ANALYSIS OF MILK.
CHAPTER II.
QUANTITATIVE ANALYSIS OF MILK.
640. Two portions of milk, one weighing about 100
grains and the other about 400 grains, are to be accurately
weighed, the first in a platinum crucible or capsule, and
the second in a porcelain capsule; both the vessels having
been previously weighed or counterpoised. The first
portion, of 100 grains, we will call A, and the second, of
400 grains, will call B.
641. T-'eatment of the portion A.-This portion, after
being weighed, is to be evaporated to dryness on a waterbath, or, still better, on a chloride-of-calcium bath heated
to about 220~, until, on being weighed at intervals of
half an hour or an hour, it ceases to lose any further
weight. The weight of the dry residue will then represent the amount of SOLID MATTER contained in the
quantity of milk used, while the loss of weight during
evaporation shows the amount of WATER.
642. In these and the other determinations, the proportion present in 1000 parts of the milk is calculated in
the following manner:Wt. ofmlk     Wt. of each          Proportion of that )
used in the:   constituent: 1000  constituent in 1000
experiment.   I obtained.         parts of the milk.
643. The weight of the dry residue having been noted,
the crucible, with its contents, is to be placed over a
lamp, and kept at a red heat until the whole of the charcoal is burnt away, and the ash becomes white or nearly
so. The weight of the ash thus obtained will represent
the amount of INORGANIC SALINE MATTER in the quantity
of milk evaporated; from which the proportion in 1000
parts may be calculated as before (642).*
* See foot-note to paragraph 63.




QUANTITATIVE ANALYSIS OF MILK.   233
744. Treatment of the portion B.-This portion, after
being weighed, is to be mixed with about one-fourth its
weight of fine-pounded hydrated sulphate of lime (CaO,
S0O+2Aq) or unburnt gypsum, with which it is to be
well stirred for a short time, and then raised to a temperature of 212~; by which means the whole of the
casein will become coagulated, and insoluble in water.
The mixture is now to be evaporated to dryness on a
water-bath, being occasionally stirred, in order that the
solid residue of the milk may be pretty uniformly mixed
with the sulphate of lime.
645. The mass, when dry, is then easily reduced to
powder, after which it is to be digested with successive
small quantities of ether (545), which will dissolve out
the whole of the fatty matter. The ethereal solution is
now evaporated to -dryness on a water-bath, and the
residue weighed; its weight representing the amount of
FAT in the quantity of milk operated on; from which the
proportion present in 1000 parts of milk may be calculated as before (642).
646. The portion of the residue which proved insoluble
in either (645) is now to be treated with hot, moderately
strong alcohol, as long as anything dissolves. In this
way, the whole of the sugar, together with a little
saline matter and alcohol-extractive, is dissolved. The
alcoholic solution is to be evaporated to dryness on a
water or chloride-of-calcium bath, and the dry residue,
having been accurately weighed, is incinerated; the difference between the weight before and after incineration
will then represent the quantity of SUGAR, with a little
alcoholic extractive matter, in the portion of milk employed. The proportion contained in 1000 parts is then
calculated as in former cases (642).
The sugar may be much more exactly determined by
means of the alkaline copper-solution, as described at
(352). 100 grs. of the milk are acidified with hydrochloric acid, heated to coagulate the casein, and filtered;
after washing the coagulum once or twice with water, the
filtrate and washings are boiled in a flask for about an
hour, replacing the water which evaporates, in order to
convert the milk-sugar into grape-sugar, since the former
20*




234          MILEK DURING DISEASE.
does not reduce the same proportion of oxide of copper.
The volume of the liquid is then made up to 1000 grs.,
and the determination proceeded with as in (352).
647. The proportion of CASEIN may be estimated by
adding together the amount of water, fat, sugar, and
saline matter, already ascertained as being present in
1000 parts of the milk, and deducting the sum of them
from 1000.
648. The casein may also be approximately determined
in another weighed portion of milk by acidulating with
acetic acid, boiling, collecting the curd upon a weighed
filter, washing two or three times and drying at 212~.
From its weight that of the fatty matter contained in the
milk (645) should be deducted.
CHAPTER III.
MILK DURING DISEASE.
649. THE milk which is secreted during disease is
usually more or less modified in its composition; even
slight derangements of the system, and any great mental
anxiety or sudden emotion of fear, &c., not unfrequently
have the effect of disturbing, in a remarkable manner,
the natural character of the secretion. The exact nature
of these changes is very imperfectly understood. They
are probably sometimes merely variations in the relative
proportions of the several constituents of the healthy
fluid; at others, and perhaps more frequently, certain
abnormal matters are formed.
650. With the assistance of the microscope, we are not
unfrequently able, with great facility, to detect the presence of certain morbid products which are not found in
the healthy secretion. The peculiar form of milk called
the colostrum, which is secreted during the first few days
of lactation, has been already mentioned as differing very
considerably in microscopic appearance from healthy
milk, and as containing numerous granular corpuscles,




MILK DURING DISEASE.               235
much larger than the ordinary milk globules (633). The
corpuscles of the colostrum  also show a tendency to
adhere to each other, while the globules of the healthy
fluid usually float freely about. It occasionally happens
that the milk, instead of changing, in the course of a few
days, to its more natural condition, continues for a length
of time to possess the characters peculiar to colostrum;
and has even been observed to change back again to this
condition, after being secreted for a time in a healthy
state. The presence of the colostrum  corpuscles (Fig.
70), and the slightly viscid appearance also characteristic
of this condition, may at once be detected under the
microscope.
651. The presence of pus, which during the formation
of a mammary abscess often finds its way into the milk,
may also be detected under the microscope, by the occurrence of the peculiar pus granules (Fig. 71). Bloodcorpuscles, too (451), are also found though more rarely
than those of pus, owing, in most cases, to the rupture
of some of the minute bloodvessels with which the
mammary gland is permeated (Fig. 72.)
Fig. 71.                   Fig. 72..   
Io oc~;9 o0 o
o                    V   [,al
o   ol O                   @   e 
Pus in Milk.             Blood in Milk.
652. Urea is said to have been found in the milk of
women affected by Bright's disease. In addition to the
strictly morbid products, other substances, especially
certain salts, which have been taken into the system either
in the food or as medicine, appear occasionally to find
their way into the milk, where they may sometimes be
detected by the proper tests.




236       THE ADULTERATIONS OF MILK.
Analysis of the colostrum of a woman, together with that of the Healthy
Milk of the same individual, (Simon.)
Colostrum.   Healthy
Milk.
Water..828'0  887-6
Solid constituents. 172'0       112-4
Fat.500  25'3
Casein.400   34'3
Sugar of milk.                 70'0       48'2
Saline matter.                  3'1        2'3
CHAPTER IV.
THE ADULTERATIONS OF MILK.
653. It is well known that much of the milk which is
supplied in large towns is almost constantly more or less
adulterated, and although the substances employed for
the purpose are in most cases comparatively innoxious,
it is much to be wished, that some simple and efficient
test of its genuineness and purity could be devised, capable of being applied by those who are unaccustomed to
experiment.
654. The chief mode of adulteration practised in this
country consists in diluting the milk with water, and at
the same time occasionally removing the cream. To
correct the bluish color of the impoverished milk, it is
said that a little annatto is sometimes added.  Milk has
been occasionally found adulterated with gum, flour, and
starch to conceal its diluted condition, and it is even
asserted that the clumsy fraud of adding chalk and emulsion of sheep's brains has been detected.
655. On examining a little of the milk under the microscope, the peculiar granules of starch and flour may be
readily seen (Fig. 73a), larger and more oval than the
milk globules if either of those substances is present;
and when examined with polarized light, each granule
will be found to exhibit a dark cross, as shown at b in
the figure. Should any doubt exist as to their real
nature, the addition of a drop or two of a solution of




THE ADULTERATIONS OF MILK.             237
iodine will impart to the farina granules a dark purple
color.
Fig. 73.
Starch Granules.
Gum  may be detected by acidulating the milk with
acetic acid, boiling, filtering off the coagulum, and mixing
the filtrate with alcohol, when the gum is deposited and
may be recognized by its behavior with water. The
presence of annatto would cause the milk to assume a
brown color on addition of carbonate of soda.
656. The microscope will also serve to show the presence of macerated brain, which may be recognized by
the occurrence of fragments of nerve and other organized
structures, not found in pure milk.
657. The presence of chalk may be still more easily
discovered, since, owing to its specific weight, it soon
subsides to the bottom of the liquid, where it may at
once be recognized by its effervescing on the addition of
a little dilute hydrochloric acid.
658. We have no chemical means of ascertaining
whether water has been fraudulently added to milk, the
only effect being to dilute it, and render it of poorer
quality, which might arise from natural causes. A
knowledge of the specific gravity will not even allow
us to decide as to the richness of the milk, since the
abstraction of a portion of the cream, which has a lower
specific gravity than milk, may be made to neutralize
the effect produced by the addition of water; the tendency of the removal of the cream being to raise the
specific gravity of the fluid, and that of the addition of
water, to lower it. A specimen of milk, therefore, which
has been impoverished by the abstraction of its cream




238      THE ADULTERATIONS OF MILK.
and still further weakened by the addition of water, may
be made to possess the same specific gravity as it had
when taken from the udder.
For most practical purposes it is sufficient to compare
the relative volumes of cream furnished by equal quantities of different specimens of milk. This may be readily
effected by allowing the milk to stand in a graduated
tube (lactometer) for twenty-four hours, at a moderate
temperature, and measuring the number of divisions
occupied by the cream.
Another method proposed by Daubrawa for the rapid
determination of the quality of milk consists in mixing
it with two volumes of alcohol of sp. gr. 0-833, filtering
off the butter and casein (which may be dried and
weighed), and taking the specific gravity of the filtrate.
Every increase of -004 in the specific gravity above
0'905 (the sp. gr. of the mixture of alcohol with the
water of the milk) indicates 1 per cent. of milk.sugar.
For example, if the specific gravity of the filtrate be
0-922, there would be 4-25 per cent. of milk sugar, for
0'922-0 905=-017, and -017- 004=4 — 25. The result
may be controlled by evaporating the spirit, converting
the milk-sugar into grape-sugar by boiling with a little
dilute sulphuric acid, rendering the solution alkaline by
potash, and determining the sugar by the standard copper solution (352).
659. It occasionally happens that the milk exposed
for sale is the produce of an unhealthy animal. Such
milk has usually some peculiarity of taste or smell, and
also a slightly viscid and unnatural appearance; on being
examined under the microscope, too, it will probably be
found to contain pus or mucus corpuscles, or to present
other appearances differing from those of the healthy
secretion.




BILE.                      239
CHAPTER V.
BILE.
659a. THE bile consists essentially of an aqueous solution of two salts, known as cholate (or glycocholate) and
choleate (or taurocholate) of soda. It is generally, but
not always, alkaline.
Bile is remarkable, among the secretions of the animal
body, for the large proportion of carbon which it contains.  Cholic acid (llO,C52114NO,,) contains 67 per cent.,
and choleic acid (IO:Cei2H44ANO13S2) 60'5 per cent. of carbon. There are also present in bile a quantity of mucus,
to which it owes its viscidity, a peculiar coloring matter,
and minute quantities of cholesterine, oleine, margarine,
and lecithine (a phosphorized fat discovered in bile by
Gobley,'* and also found in serum), together with chloride
of sodium, and alkaline and earthy phosphates.
Cholic acid.-To isolate this acid, the bile is evaporated
to dryness, the residue dried at 2500 Fahr. and digested,
in the cold, with absolute alcohol. The coloring matter
is precipitated from the alcoholic solution by the gradual
addition of ether, and the clear solution decanted from
the deposit is mixed with more ether, when it gradually
deposits tufts of needles consisting of the cholates of
potash and soda. After having been washed with a mixture of absolute alcohol, with ITth ether, the crystals are
dried in vacuo, dissolved in a little water, and decomposed by dilute sulphuric acid, when cholic acid slowly
separates in silky crystals, which are sparingly soluble
in cold water, and in ether, but readily in alcohol.
When cholic acid is boiled with dilute hydrochloric
* Journ. of Pharm., xxx. 241. Strecker has recently discovered
lactic acid in bile, together with a new alkaline base- CUholine C 0H1,NO2.




240                     BILE.
acid, it assimilates the elements of water, and is decomposed into choloidic acid and glycocine (or sugar of
gelatine):Cholic acid.  Choloidic acid.  Glycocine.
HO,C521H42NOl, + HO= —C48H3909 + C4H6N04o
Choleic acid.-This acid is not nearly so abundant in
the bile as the preceding. In order to obtain it, the bile
is mixed with water, and acetate of lead added to separate
the mucus, the cholic, and the fatty acids. From the filtered liquid, the color is removed by adding tribasic
acetate of lead till the precipitate is white, and after filtration, the choleic acid is precipitated by adding more
tribasic acetate of lead and ammonia. The lead salt is
dissolved in alcohol, filtered, reprecipitated by water, and
decomposed by sulphuretted hydrogen. The solution
filtered from the sulphide of lead is evaporated, when it
leaves the choleic acid.
When boiled with acids, choleic acid is decomposed,
with the concurrence of the elements of water, into a
new acid, and a peculiar crystalline body called taurine:Choleic acid.    Cholalic acid.   Taurine.
HO, C52H44NO lS- 2 2H=-H,C48H3909- C4H7N06S2.
Taurine, which has also been found in the kidneys and
in the lungs of the ox, is conspicuous among organic
substances, for the large amount of sulphur which it
contains (25'6 per cent.). It may be prepared in quantity by mixing bile with hydrochloric acid, filtering it
from the mucus, and boiling for some hours. The clear
liquid having been poured off from the resinous deposit,
is evaporated to a small bulk on the water bath. The
solution is drained from the crystals of chloride of sodium,
and mixed with six volumes of alcohol.  On standing,
prismatic crystals of taurine are deposited, and may be
recrystallized from water in order to purify them. It is
insoluble in absolute alcohol and ether, and not.very
soluble in cold water. It mav be identified by the odor
of sulphurous acid when a crystal is heated on platinum
foil.
Coloring matter of bile.-Two coloring matters have




BILE                       241
been obtained  from  bile, one of which, biliverdine, is
easily soluble in alcohol, whilst biliphaeine dissolves with
difficulty. In order to separate them, Brucke recommends that the bile be well shaken with chloroform,
which extracts the biliphbeine. On evaporating the chloroform, and treating the residue with strong alcohol, the
coloring matter is left in red crystals, which may be
purified by washing with alcohol and ether. If bilipheine
be dissolved in carbonate of soda, the solution oxidized
by exposure to air, and neutralized with hydrochloric
acid, a precipitate of biliverdine is obtained.
In Bright's disease, it is said that albumen and urea
bave been found in bile.
Sugar forming substance in the liver.-If a fresh liver
be cut into thin slices, heated with a small quantity of
water, the solution filtered, evaporated to a small bulk,
and mixed with a large excess of glacial acetic acid, a
white fiocculent precipitate is obtained which has the
composition C12H,,oOo (Kekuld).  This substance, which
resembles starch in some of its properties, as well as in
its composition, has been called animal amyloid, hepatine,
and glycogene. Like starch, it is converted into grapesugar when boiled with dilute acids, but it gives a dark
brown-red, instead of a blue color, with iodine.  It dissolves in water, giving a strongly opalescent fluid which
is precipitated by alcohol.  Sugar is also found in the
decoction of liver, but it is doubtful whether it exists in
the organ during life, or results from  a post-mortem  conversion of the glycogene.  This substance has also been
obtained in the milky fluid resulting from the injection
of water into the liver in preparing it for the ordinary
process of injection.
* According to Pelouze, C,2H1,,O,1+HO.
21




242               JUICE OF FLESH.
CHAPTER VI.
JUICE OF FLESEH.
IF a few pounds of finely divided flesh be digested for
a short time in cold water, and afterwards well squeezed
in a muslin bag, a reddish acid* liquid is obtained, containing a little blood, together with the constituents of
the juice of flesh, viz., albumen, kreatine, kreatinine, sarcine, inosite; lactic acid, butyric acid,t phosphoric acid,
in combination with potash, lime, and magnesia; and
chloride of potassium with a little chloride of sodium.
Kreatine (C,8HN304,2Aq).  To extract this substance,
the above infusion is heated in a water-bath until the
whole of the albumen is coagulated; it is then strained,
and mixed with baryta-water until it is alkaline to turmeric paper. The precipitate (phosphates of baryta, lime,
and magnesia) is filtered off; and the solution evaporated
to a syrup. After standing for a few days, it will deposit prismatic crystals of kreatine, which may be purified by recrystallization, with the use of a little animal
charcoal.
1000 parts of beef yield about 0'7 of kreatine, 1000
parts of cod-fish, 1]3 parts, and 1000 of fowl about 3
parts. Human flesh is said to be particularly rich in
kreatine.
Kreatine has no alkaline reaction, but is capable of
forming crystalline salts with acids. It dissolves in 75
parts of cold, and in much less boiling water. It is very
slightly soluble in alcohol, and insoluble in ether.
A pure solution of kreatine will not give any precipitate with solution of chloride of zinc, but if the solution
* According to Du Bois Reymond, the juice of the flesh is naturally
alkaline, but becomes acid very speedily after death.
t Scherer has also found formic and acetic acids in the juice of flesh.




JUICE OF FLESH.                  243
be previously boiled for some time, kreatinine is formed,
which yields, with chloride of zinc, a granular crystalline
precipitate:Kreatine.       Kreatinine.
CsH9N304 - 2HO  CsH7N302O
The conversion is much accelerated by the addition of
a little hydrochloric or sulphuric acid.
If kreatine be dissolved in water and boiled with 10
parts of crystallized baryta, as long as any ammonia is
disengaged, it yields a new base, sarcosine, which may be
obtained in prismatic crystals by saturating the solution
with carbonic acid gas, boiling to precipitate the excess
of baryta, and evaporating the filtered liquid to a small
bulk:Kreatine.  Sarcosine.    Urea.
CsH9N304 = C6H7XI04 + C2H4N202.
The urea, which is the other product of this decomposition
of kreatine, is decomposed by the ebullition with baryta
into carbonic acid and ammonia.
Jreatinine. If the liquid from which the crystals of
kreatine were deposited be mixed with a strong solution
of chloride of zinc, and set aside, crystals of the compound
of kreatinine with chloride of zinc will be separated. The
preparation and properties of kreatinine have been described under the head of urine (30a).
Sarcine (C,,0H4N4,0). To obtain this base, the motherliquor from the crystals of kreatine is diluted, and mixed
with a dilute solution of acetateof copper. The precipitate
is washed, suspended in water, and decomposed by
sulphuretted hydrogen; after filtering from the sulphide
of copper, the solution is gently heated on a water-bath
to expel the excess of sulphuretted hydrogen, and boiled:
with hydrated oxide of lead to remove the coloring matter.
After another filtration, sulphuretted hydrogen is again
passed through the solution, the sulphide of lead filtered
off, and the filtrate evaporated to a small bulk, when it
deposits crystals of sarcine.
This substance, like kreatine, is a weak base, forming
salts with acids. It is much less soluble in water than
kreatine, requiring 300 parts of cold and 78 parts of




244               JUICE OF FLESH.
boiling water.  It is much more sparingly soluble in
alcohol.
The composition of sarcine is the same as that of hyooxanthine, another basic substance which has been found
in the spleen.
Inosite (ClH 12012,4Aq). This substance, as well as inosic
acid (HO,CoEl6N201o) does not appearto be so invariably
present in the juice of flesh as kreatine is.* In order to
extract it, if present, from the mother-liquor after the
separation of the kreatine, dilute sulphuric acid is added,
in quantity exactly sufficient to precipitate the baryta,
and the filtered liquid is well shaken with ether, which
removes the lactic acid. To the aqueous liquid, alcohol
is then added in successive portions; the first addition
causes a precipitation of sulphate of potash and other salts,
and after separating these and a further addition of
alcohol, small crystals of inosite are deposited.
This body is remarkable for its sweet taste, and for
having, when dried at 212~, the same composition as grapesugar dried at that temperature (C12HE2012). It differs
filom that substance, however, in not reducing the oxide
of copper in alkaline solution to the state of suboxide, and
in not giving a brown solution when boiled with potash.
Neither can it be made to undergo the vinous fermentation.  Inosite is readily dissolved by water, but is
insoluble in absolute alcohol and in ether.  It is said to
exist to the extent of A per cent. in unripe beans.
Lactic acid (210,C12H,,,0o).  The lactic acid extracted,
as described above, by ether, from  the juice of flesh, is
commonly called sarco-lactic acid, to distinguish it from
ordinary lactic acid obtained by the fermentation of milksugar (621). Although the properties of both varieties
of lactic acid in the free state are similar, their salts are
not precisely so. The sarco-lactate of zinc has the formula,
2ZnO,Cl1211o0010,4Aq, whilst the ordinary lactate of zinc
contains 6Aq. Again, the sarco-lactate of lime is 2CaO,
C12H10010,8Aq, and the ordinary lactate, which is also the
more soluble in water, contains 10OAq.
* It was originally obtained from the heart, but has recently been
found in the kidneys, liver, spleen, and lungs of the ox.




MuCUs.                    245
The lactic acid is obtained by evaporating the ethereal
solution, as a syrupy acid liquid, which does not crystallize,
and is best characterized by boiling it with a few zincfilings, when the lactate of zinc will be formed, which
deposits in sparingly soluble crystalline crusts.
Butyric acid (HO,CH,703). By acidulating the motherliquor from the kreatine with sulphuric or hydrochloric
acid, and distilling, a very dilute solution of butyric acid
is obtained. The acid may be identified by its odor of
rancid butter, and in order to obtain it in a pure state,
the acid distillate from a large quantity of flesh must be
neutralized with baryta and evaporated, when butyrate
of baryta crystallizes out. By dissolving this in a little
water and adding just enough sulphuric acid to precipitate
the baryta, a concentrated' solution of the acid may be
obtained. By introducing into this, in a tube, fragments
of fused chloride of calcium, the butyric acid is separated
and rises, as an oily layer, to the surface, whence it may
be drawn off; and purified by distillation with a little
more chloride of calcium.
CHAPTER VII.
MUCUS.
SECTION I.
General Characters of Mucus.
660. HEALTHY mucus, which is secreted by the mucous
membrane with which the internal surfaces of the several
parts of the body are covered, is a semi-fluid viscid substance, the general appearance of which is well known.
It is sometimes so thin and limpid as almost to resemble
water in appearance; while at others, and more commonly,
it is tough and extremely tenacious, becoming stringy
when attempted to be drawn out. When thin and watery,
it is nearly transparent and colorless; the more viscid
21*




246                   Mucus.
forms, however, being turbid or opaque, and usually of
a pale yellowish or grayish color. It is generally alkaline
to test paper, insoluble in water, and somewhat heavier
than that fluid; so that when placed in water it gradually
sinks to the bottom, unless it is buoyed up by entangled
air-bubbles. The mucus obtained from the several parts
of the body differs considerably in appearance, and probably also in chemical composition. When dry it is hard
and friable, resembling horn in appearance; the dry mass,
on being digested in water, gradually swells up, and partially reassumes its former appearance.
661. When mucus is examined under the microscope,
with a power of about 200 diameters, it is found to contain numerous round or oval granular corpuscles, together
with epithelial scales (Fig. 5), entangled in a more or less
viscid fluid, to which latter the peculiar tenacious character of mucus appears to be due. Mucus, therefore,
consists of two distinct portions: the solid corpuscles
with epithelial scales, and the fluid with which they are
surrounded. Under favorable circumstances, and with a
high magnifying power, the fluid portion appears to be
filled with extremely minute molecular particles, the
nature of which is not clearly understood.
662. The size of the mucus corpuscles varies considerably, the average diameter being about g,o'th of
an inch. Their surfaces are granular, similar to those of
pus; and when treated with dilute acetic acid, the exterior covering loses its granular appearance, and becomes
transparent, rendering visible from one to five internal
nuclei. The same effect is produced by dilute oxalic and
tartaric acids; but the dilute mineral acids cause little or
no change.
663. Mucus appears to contain in its composition the
following substances: mucus corpuscles, epithelial scales,
mucin, traces of extractive matters and fat, sometimes a
small trace of albumen, and saline matters; which latter
consist of alkaline chlorides and lactates, phosphate of lime,
and traces of carbonate of soda. The mucin, to which the
peculiar tenacious character of mucus appears to be due,
is insoluble in pure water, and is probably held in solution in the fluid portion of the mucus, by the small




QUANTITATIVE ANALYSIS OF MUCUS.   247
excess of alkali usually present; it separates in the form
of a white coagulum when mucus is treated with water,
and still more completely when neutralized with dilute
acetic acid. The minute traces of fat found in mucus
probably exist in the corpuscles, though the exact chemical nature of these is by no means clearly ascertained.
SECTION II.
Quantitative Analysis of Mucus.
664. The quantitative determination of the principal
constituents of mucus may be made in the following
manner. The mucus intended for analysis is first divided
into two portions, A and B; the first, A, being about onequarter, and the second, B, about three quarters of the
whole. Both portions are to be weighed in counterpoised
capsules, that containing A being a platinum, and evaporated to dryness on a chloride of calcium bath, at a
temperature of about 2200.
665. Treatment of the portion A. —This portion, after
being dried until it ceases to lose weight, is to be accurately weighed. The weight of the dry residue gives
the amount of SOLID MATTER in the quantity of mucus
evaporated, while the loss represents the amount of WATER.
666. The proportion of these and the other ingredients,
contained in 1000 parts of the mucus, may in each case
be estimated by the following circulation:Weight      f Wt, of each con- 7    f Proportion of that
mucus W t o.: -s tituentcontained: *: 1000: constituent conbefore eva-  I in the quantity of      taied in 1000
poration. J  L mucus employed. J      parts of mucus. J
667. The dry residue is then to be incinerated at a
low red heat, until the ash becomes white, or nearly so.
The weight of the ash will then represent the amount of
SALINE MATTER in the quantity of mucus used; from
which the proportion present in 1000 parts may be calculated -as before (666).
668. Treatment of the portion B. —The dry residue left
after evaporation (664), is to be removed from the capsule,
and reduced to fine powder in a mortar. It is then
boiled with successive small portions of ether, which will




248               MORBID MUCUS.
dissolve out the fat (515). The ethereal solution is evaporated to dryness on a water-bath, when the weight of
the residue will indicate the amount of FAT in the quantity of mucus employed; from which the proportion in
1000 parts may be estimated as before (666).
669. The residue which proved insoluble in the ether
(668) is to be boiled with a little alcohol, after which the
alcoholic solution is to be evaporated to dryness, and the
dry residue weighed. This is then incinerated, and the
weight of the ash, deducted from that of the dry extract,
will give the amount of ALCOIIOLIC EXTRACTIVE, with the
lactic acid of the lactates, in the quantity of mucus used;
which may be corrected, as before, for 1000 parts (666).
6 70. The portion of the residue which proved insoluble
in the alcohol (669) is to be dried and weighed; the weight
indicating the amount of MUCIN, together with cellular
matter, and probably traces of albumen, in the quantity
of mucus employed; from which the proportion present
in 1000 parts of mucus may be calculated, as in the
former cases (666).
671. According to Nasse, the composition of fresh pulmonary mucus is as follows:Water....955-520
Solid constituents..                  44-480
Mucin, with a little albumen...  23754
Water extract.                      8006
Alcohol extract......   1-810
Fat...... 2.887
Chloride of sodium                      5825
Sulphate of soda.....             0400
Carbonate of soda.....              0198
Phosphate of soda......   0080
Phosphate of potash, with traces of iron.   0-974
Carbonate of potash....     0291
Silica, and sulphate of potash    -.    0 0255
SECTION III.
Morbid Mucus.
672. The characters of mucus secreted during disease
are usually more or less different from those of the normal secretion, and an admixture of foreign matters frequently alters its appearance considerably.  Pus, for




GENERAL CHARACTERS OF PUS.             249
instance, when mixed with it, diminishes its tenacity,
owing to the mucin being present in smaller proportion
(663); and when the liquid portion of mucus containing
an admixture of pus is tested for albumen (254, 667), a
considerable amount of that substance may usually be
detected; since the liquor puris, or liquid portion of pus,
contains a Comparatively large quantity of albumen, but
no mucin. Our means of detecting the presence of minute
traces of pus in mucus are very imperfect; the decided
presence of albumen in the purulent secretion is, indeed,
almost the only test, since the microscopic characters of
the corpuscles appear to be very similar (249).
673. The morbid mucus expectorated in pulmonary
disease frequently contains, besides pus, red blood corpuscles, minute globules of fat, fragments of tuberculous
matter, and other abnormal substances, most of which
may generally be detected without difficulty under the
microscope. The indications afforded by a careful microscopic examination of such expectorations, indeed, may
often lead to results in diagnosis, of great importance to
the practical physician.
CHAPTER VIII.
PUS.
SECTION I.
General Characters of Pus.
674. Pus is the peculiar semi-fluid matter which is
formed in abscesses, and in other kinds of wounds. In
common language, a considerable variety of substances,
more or less resembling each other in appearance, though
differing in many respects, are included under the name
of pus; and hence it has been found necessary to distinguish the normal secretion by the name of true or genuine
pus; the other substances being called spurious orfalsepus.
675. Normal pus is a thick creamy-looking fluid, per



2O0      GENERAL CHARACTERS OF PUS.
fectly opaque, and usually of a pale yellow or greenish
color. It possesses little or no tenacity, and may consequently be poured in separate drops; in which respect it
differs essentially from  mucus, which, in  color and
general appearance, it often much resembles. Its specific
gravity is usually about 1030 or 1033, so that it sinks in
water; and if shaken up with that fluid, mixes uniformly
with it. The mixture, after standing a short time,
gradually deposits a sediment, consisting of pus-corpuscles (678). It is most commonly neutral to test paper,
but is also occasionally met with slightly acid or alkaline.
676. Like mucus, pus consists of a clear fluid portion
or serum, in which float innumerable minute granular
corpuscles, which latter appear to be almost precisely the
same as those contained in mucus, and when examined
under the microscope, exhibit the same granular appearance. The liquid portion of pus, or liquor puris, however, differs essentially from that of mucus, and contains
the following substances in solution, which, it will be
seen, are nearly the same as those held in solution in the
serum of the blood (568)-viz., albumen, together with a
peculiar compound called pyin, or tritoxide of protein
(which is soluble in water, and precipitated by acetic acid),
fat, cholesterin, extractive matters, and inorganic salts.*
These latter consist, for the most part, of chloride of
sodiuim, with small quantities of phosphate, sulphate, and
carbonate of soda; the chlorides of potassium and
calcium; phosphates and carbonates of lime and magnesia;
and traces of peroxide of iron.
677. The presence of these matters in the liquor puris
may be shown by placing some pus in a tall narrow
glass, and allowing it to stand, in order to give the corpuscles time to subside; after whidh, a little of the clear
liquid may be drawn off with a pipette. On boiling a
few drops of this in a test-tube, the albumen becomes
coagulated, and separates from the liquid: after which
the pyin may be thrown down in the form of a white
flocculent precipitate, by adding a little acetic acid.t  The
* Leucine (C,2H,,NO4) has also been found in pus.
t Pyin is precipitated by chloride of mercury and by acetate of
lead, which is not the case with macin.




GENERAL CHARACTERS OF PUS.             251
liquid may then, if necessary, be tested for the several
inorganic salts above enumerated (676, 490).
678. The pus-corpuscles, though quite invisible to the
naked eye, may be distinguished under the microscope
with a magnifying power of from fifty to one hundred
d i a m e t e r s; a considerably
higher power, however, is re-         Fig. 74.
quired for exhibiting their
peculiar  granular  structure    a   4~
(Fig. 47, a). The size of these 
corpuscles varies considerably,    %  Ad 
being commonly about oth0
of an inch in diameter. They
are nearly spherical; and have    P diamets-orpsces agnified
a very pale yellowish color,
which is scarcely perceptible, unless several of them are
aggregated together. Being slightly heavier than the
liquor puris with which they are surrounded, they
gradually subside to the bottom, leaving the fluid portion
nearly clear. Minute globules of fat may usually be
detected, mixed with the corpuscles.
679. The pus-corpuscles, when treated with liquids of
different densities, exhibit the phenomena of endosmosis
and exosmosis, somewhat similar to those already
described as taking place in the corpuscles of the blood
(456); increasing in size when the external liquid, such
as pure water, is of lower density, and collapsing when
it is of higher density, than the fluid contained in them.
When treated with dilute acetic acid, the external covering becomes transparent, and exhibits one or more
internal nuclei (Fig. 74, b).
680. When mixed with a solution of ammonia or potash, pus loses its fluidity, and assumes a jelly-like appearance, which is highly characteristic, and is employed to
distinguish it from mucus, which becomes less tenacious
than before when treated with alkalies. A somewhat
similar effect is produced also by the alkaline carbonates,
and certain other salts.
681. Although the general appearance and characters
of pus are usually sufficiently marked to enable us to
identify it, it is always advisable, in cases where any




252     QUANTITATIVE ANALYSIS OF PUS.
doubt exists, to submit it to microscopical examination;
since occasionally we meet with fluids containing a large
quantity of epithelium and other products, which, in
appearance, closely resemble pus, though differing entirely
in composition from that substance, and containing no
trace of the characteristic pus-corpuscles (678). The form
of the corpuscles is found to vary considerably under
certain pathological conditions; but there may generally
be traced sufficient resemblance to the normal corpuscles
to enable us to distinguish them  from  other matters.
The modes of distinguishing between pus and mucus,
have been already noticed in paragraphs 248, &c.
681a. Blue pus.-In certain rare cases, the bandages
upon which pus has been discharged assume a blue
color. By treating them with water, and agitating the
aqueous solution with chloroform, Fordos has extracted
a blue crystalline coloring matter, which he calls pyocyanine. It is soluble in water, alcohol, and ether; its
color is changed to red by acids, but the blue is restored
by alkalies.
SECTION II.
Quantitative Analysis of Pus.
682. The quantitative analysis of pus may be made in
the following manner: Two portions of the fluid are to
be weighed out; the first, A, in a small counterpoised
flask; and the second, B, in a counterpoised or weighed
evaporating dish.
683. Treatment of the portion A. —The portion A, after
being weighed in a flask, is to be boiled with successive
small quantities of strong or absolute alcohol, which
must be separated while hot, either by filtration or
decantation, from the insoluble portion. The alcoholic
solution is then set aside to cool, and allowed to stand
a few hours, in order that the fat may, for the most part,
crystallize out. The cold alcoholic liquid is then poured
off, and the solid matter dried and weighed; when the
weight thus obtained will represent the amount of FAT
in the quantity of pus employed in the experiment.
6R4. The cold alcoholic liquid (6t3) is now to be




QUANTITATIVE ANALYSIS OF PUS.    253
evaporated to dryness, on the water-bath, in.a counterpoised platinum capsule, and the dry residue, after being
weighed, is incinerated. The weight of the ash is then
ascertained, when the difference between the weight
before and after incineration will represent the quantity
of EXTRACTIVE MATTER (together with traces of fat which
had not separated fromn the cold alcohol), in the portion
of pus employed.
685. The residue which proved insoluble in the boiling
alcohol (683), is to be dried on a water-bath, and then
boiled with a little water, which will dissolve out the
pyin, and at the same time cause the coagulation of the
albumen. The aqueous solution thus obtained is to be
separated from the insoluble portion; evaporated to dryness in a platinum capsule on a water-bath; and the
weight of the dry residue having been noted, it is to be
incinerated. The difference between the weight of the
dry residue previous to incineration, and that of the inorganic ash, represents the amount of PYIN in the portion
of pus used in the experiment.
686. The matter which remained insoluble in the hot
water (685), is now to be dried and weighed. The dry
residue is incinerated; and the loss of weight which it
experiences during incineration will show the amount of
ALBUMEN AND CORPUSCLES in the quantity of pus operated
on.
687. Treatment of the portion B.-The weight of this
portion having been noted, it is to be evaporated to dryness on a chloride-of-calcium bath, at a temperature of
about 220~, the heat being continued until it ceases to
lose weight on being weighed at intervals of half an hour
or an hour. The loss of weight during the evaporation
will then represent the proportion of WATER in the
quantity of pus employed; while the weight of the dry
residue shows the amount of SOLID MATTER.
688. The dry residue is now to be incinerated in a
platinum capsule or crucible, until the ash becomes white
or pale gray. The weight of the ash will then show the
amount of inorganic SALINE MATTER in the quantity of
pus used in the experiment.
689. The proportion of the several constituents con22




251    GENERAL CHARACTERS OF BONE.
tained in 1000 parts of pus, may then be estimated from
the numbers obtained in the above experiments, by the
following calculation:I Wt. of pus )  {Wt. of each              Proportion of that
used in the I:. constituent::1000      constituent in
experiment. J  I obtained.              1000 parts of pus.
690. From the analysis of Dr. Wright, the composition
of pus appears to be as follows: —
Pus from a
Pus from Pus from a psoas mammary
a vomica.   abscess.   abscess.
Water...           894'4     885 2      879'4
Fatty matter.17 5                    28.8       26.5
Cholesterine...      54 
Mucus....    11-2           6.1
Albumen....    68'5          63'7       83'6
Lactates, carbonates, and
phosphates of soda, pot-    9*7      13'5        8.9
ash, and lime.
Iron....   a trace.
Loss....        3-3       2'7        1'6
1000.0    1000'0     1000'0
CHAPTER IX.
BONE.
SECTION I.
General Characters of Bone.
691. THE color, texture, specific gravity, and general
characters of bone, differ very much in different parts of
the body; and the proportions of the several chemical
ingredients are also found  to vary considerably.  The
two principal constituents of bone are cartilage* and
* Called ossgine by Fremy, who states that it contains the same
proportions of carbon, hydrogen, nitrogen, and oxygen as gelatine,
into which it is convertible with a facility which is inversely as the
age of the animal.




GENERAL CHARACTERS OF BONE.             255
phosphate of lime (3CaO,PO,); the proportion of the
former being usually about 29 to 34 per cent., and that
of the latter from 50 to 60 per cent. of the entire bone.
The other substances, which are present in smaller quantity, are, carbonate of lime (CaO,CO2); phosphate of
magnesia (3MgO,PO5); fluoride of calcium (CaF); soluble soda salts, chiefly chloride of sodium; traces of the
oxides of iron and manganese; and fat; which latter,
however, does not belong strictly to the bone, but to the
marrow contained in it. The presence of these several
substances may be demonstrated by the following experiments.
692. The cartilaginous matter of bone may be obtained
almost entirely free from the saline and other ingredients,
by digesting a bone for a day or two, at a temperature
not higher than about 500, in dilute hydrochloric acid,
composed of about one part of the strong acid and five
parts of water. The earthy and saline matters gradually
dissolve in the acid, leaving the cartilage unaffected, and
still retaining the exact form of the bone. In this state
it is soft and elastic; becoming, when dried, hard, somewhat brittle, and horny in appearance.
693. If the cartilage be boiled for some time in water,
it will almost wholly dissolve, being converted into gelatine (the gluten of some writers), leaving undissolved
nothing more than a delicate network of vessels. The
aqueous solution thus obtained becomes, unless very
dilute, gelatinous on cooling.
694. The fat may be separated by boiling a few fragments of crushed bone with ether, and evaporating the
ethereal solution; when the fat will be left behind as a
residue.
695. The phosphate of lime and phosphate of magnesia
may be isolated by dissolving a fragment of calcined
bone* in dilute hydrochloric acid, and supersaturating
the acid solution with ammonia; which will throw down
a white gelatinous precipitate of the mixed earthy phosphates. If this precipitate be examined under the micro* A large piece of bone may be burnt in a clear fire till perfectly
white.




256     GENERAL CHARACTERS OF BONE.
scope, it will be found to be chiefly composed of amorphous particles of phosphate of lime, mixed with a small
quantity of the crystalline double phosphate of ammonia
and magnesia (2MgO,NH40O,PO,+12Aq), showing the
presence of phosphate of magnesia.
696. The presence of carbonic acid (carbonate of lime)
may be proved by the effervescence which ensues when
a fragment of uncalcined bone is moistened with dilute
hydrochloric acid. If the solution, filtered from the precipitate of earthy phosphates (695) be tested with oxalate
of ammonia, it will be found still to contain a considerable amount of lime, which existed in the bone as carbonate; since that portion only of the lime was precipitated
by the ammonia, which was in combination with phosphoric acid.
697. If calcined bone, reduced to powder, be boiled
for some little time in a test tube or glass flask, with a
little rather dilute sulphuric acid, consisting of about
equal parts of the strong acid and water, the inner surface of the glass will generally be found to be slightly
corroded, owing to the disengagement of hydrofluoric
acid (IHF) by the action of the suilphuric acid on the
fluoride of calcium.  CaF + HO, SO= CaO,S03 + HF.
This substance, however, does not appear to be invariably present in bone, and some observers have been unable
to detect it.
698. The presence of chloride of sodium may be shown
by boiling a little calcined bone reduced to powder with
water, filtering from the insoluble earthy portion, and
testing a few drops of the aqueous solution with nitrate
of silver, which will give an abundant precipitate of the
chloride (AgC1l). By concentrating the rest of the solu.
tion to a small bulk and testing it on platinum wire in
the blowpipe flame, a yellow color will appear, showing
the presence of soda.
699. A little sulphate of soda may also be detected,
by means of chloride of barium, in the soluble portion
of calcined bone, though no trace of sulphuric acid is to
be found in it previous to calcination; being produced,
during ignition, by the oxidation of the sulphur contained in the tissues.




QUANTITATIVE ANALYSIS OF BONE.   257
SECTION II.
Quantitative Analysis of Bone.
700. About three hundred grains of the bone intended
for analysis should be first cleaned from adhering fat,
periosteum, and other impurities, and then reduced to
tolerably small fragments either by crushing or rasping.
701. Treatment of the first portion.-One hundred grains
of the bone are to be dried in a counterpoised platinum
capsule or crucible, on a chloride-of-calcium bath, at a
temperature of about 2500, until it ceases to lose weight
on being weighed at intervals of half an hour or an
hour. The loss of weight which it experiences during
desiccation- represents the percentage of WATER.
702. The dry mass is now to be incinerated in the
capsule at a low red heat, until the whole of the organic
matter is burnt away, and the ash becomes throughout
perfectly white. The weight of this ash gives the percentage of INORGANIC MATTER contained in the bone;
while the loss during incineration represents the percentage of ORGANIC MATTER. The inorganic residue may
then be digested in dilute hydrochloric acid, and retained
for subsequent examination (706).
703. Treatment of the second portion.-A second portion
of the crushed or rasped bone, weighing one hundred
grains, is to be digested for a day or two, in cold dilute
hydrochloric acid, containing one part of the strong acid
to five or six of water; the whole being kept at a temperature not higher than about 50~, as otherwise some
traces of the animal matter of the bone would be acted
upon by the acid. The whole or at least by far the
greater portion of the inorganic matter is thus dissolved,
and when the acid liquid has been well washed out of
the insoluble residue by means of cold water, little will
remain but the cartilaginous matter of the bone.
704. The cartilaginous residue is to be dried on a
water-bath, and then boiled with a little ether, which
must be poured off, and renewed, if necessary, until all
the fat is dissolved. The ethereal solution is then evaporated to dryness in a counterpoised capsule on a water22*




258    QUANTITATIVE ANALYSIS OF BONE.
bath; when the weight of residue will give the percentage of FAT in the bone.
705. The matter which proved insoluble in the ether
(704), consisting chiefly of cartilage, with traces of inorganic matter, is now to be dried on a chloride-of-calcium
bath, at a temperature of about 2500, weighed and incinerated. The difference between the weight of the dry
residue before and after incineration, will then represent
the percentage of CARTILAGE in the bone.
706. The ash left after the incineration of the first
hundred grains of bone (702), is now to be dissolved in
moderately dilute hydrochloric acid; a gentle heat being
applied if necessary. The acid solution is then slightly
supersaturated with ammonia, which will throw down the
phosphate of lime, together with the small quantity of
phosphate of magnesia and fluoride of calcium; as well
as any traces of peroxide of iron and oxide of manganese
that may be present. The precipitate is to be well washed
filtered, dried, and ignited; after which its weight will
represent the amount of BONE EARTH, consisting of PHOSPHATE OF LIME with PHOSPHATE OF MAGNESIA, and
FLUORIDE OF CALCIUM, in one hundred parts of the bone.
707. If it is required to determine separately the proportion of phosphate of magnesia, the ignited precipitate
(706), after being weighed, is to be redissolved in dilute
hydrochloric acid; the acid solution is then mixed with
an excess of perchloride of iron (Fe2Cl3) and supersaturated with ammonia. The phosphoric acid of the earthy
phosphates is thus precipitated in combination with peroxide of iron, together with any excess of uncombined
peroxide of iron, leaving in solution the chlorides of
calcium and magnesi.um. The lime (chloride of calcium)
is first precipitated by adding oxalate of ammonia (NH,
0,C203) as long as it causes a precipitate, boiling the
mixture, and filtering. The filtered solution is then
concentrated by evaporation, and the magnesia thrown
down by adding phosphate of soda (2NaO,HlO,P05) and
a decided excess of ammonia. The mixture is allowed
to stand for some hours, after which the precipitated
* The process described in paragraphs 68-71 will give more exact
results.




QUANTITATIVE ANALYSIS OF BONE.   259
double phosphate of ammonia and magnesia (2MgO,N114
O,POs+12Aq) is to be filtered, dried, and ignited, by
which it is converted into phosphate of magnesia (2Mg
O,PO5), and weighed. This weight will represent the
amount of PHOSPHATE OF MAGNESIA in the 100 grains of
bone; which, when deducted from the whole earthy
phosphates (706), will give the percentage of PHOSPHATE
OF LIME.
707a. General method of determining phosphoric acid.Since phosphoric acid is a constant component of the
inorganic parts of the solids and fluids of the body, it is
necessary to be able to determine it directly in all cases.
The opportunity may be taken of applying the following
process (Chancel) to the determination of phosphoric acid
in bone. Ten grains of the bone-ash are dissolved in
nitric acid with the aid of heat. The solution is diluted
and a little nitrate of baryta added, to remove sulphuric
acid; nitrate of silver is then added, without previous
filtration to precipitate the chlorine. The filtered solution is treated with sulphuretted hydrogen, and the
liquid filtered from the sulphide of silver is heated until
no more sulphuretted hydrogen is perceptible. A solution of nitrate of bismuth (BiO3,3NO,) is then added, and
the precipitate of phosphate of bismuth (BiO3, PO5) is
collected upon a filter, washed with boiling water, ignited in a porcelain crucible (the filter being burnt separately) and weighed. The following proportion then
gives the phosphoric acid:Ate. wt. of  Ate. wt. of
phosphate of   phosphoric
bismuth.    acid.
305         71:: Weight of precipitate: x
708. The solution filtered from the precipitate of
earthy phosphates (706), containing the portion of lime
which existed in the bone as carbonate, is now to be
treated with oxalate of ammonia as long as any precipitate is produced. The whole of the lime is thus separated
as oxalate (CaO,C0203+2Aq), which, after boiling the mixture, is filtered, dried, and ignited.* The oxalate is con* See paragraph 69.




260    QUANTITATIVE ANALYSIS OF BONE.
verted during the ignition, into carbonate (CaO,CO2), so
that the weight of the ignited precipitate will represent
the amount of CARBONATE OF LIME in the hundred grains
of bone.
709. As a check upon the estimation of the carbonate
of lime, the amount of carbonic acid in the bone may be
determined by placing 100 grains of the
Fig. 75.   unburnt bone in fine powder, in a flask,d           a, provided with a desiccating tube b,
containing fragments of chloride of calcium (Fig. 75). A  test-tube (c) containing hydrochloric acid is then placed in
[cliff\%    the flask, and the whole apparatus is
-o      weighed; after which the acid is allowed
to flow gradually upon the powder, from
which it will expel the CARBONIC ACID.
The amount of the latter which, being gaseous, escapes
in a dry state through the chloride of calcium tube d, is
then represented by the loss of weight which the apparatus with its contents experiences during the experiment (337). It will probably be found that the carbonic
acid thus determined, bears to the carbonate of lime
(708) the proportion of 22 to 50, those being the atomic
weights of carbonic acid and carbonate of lime respectively.*
710. The solution filtered from the oxalate of lime
(708), which contains the soluble salts (chiefly chloride
of sodium), together with the excess of oxalate of ammonia employed to precipitate the lime, is now to be
evaporated to dryness, and the residue ignited in order
to expel the ammoniacal salts. The weight of the residue, after ignition, will then represent the percentage of
SOLUBLE SALINE MATTER.
711. The following analyses will serve to illustrate the
percentage composition of bone both of man and some of
the lower animals.
* To obtain an exact result by this process, the flask should be
furnished with a narrow tube e, dipping into the liquid,: kept closed
during the evolution of gas; at the conclusion of the experimnent the
tube should be opened and air slowly sucked through the drying-tube
b as long as the weight of the apparatus diminishes.




QUANTITATIVE ANALYSIS OF BONE.   261
Analysis L!  ( Von Bibra.)
Showing the Composition of the Bones of a Child two months old.
Tibia.    Ulna.
Phosphate of lime, with a little fluoride }   5754    5635
of calcium.... 
Carbonate of lime...          6-02      6'07
Phosphate of magnesia...  103      1.00
Soluble salts.                               073  1'65
Cartilage*..3386  34'92
Fat.                                          082 1.01
Analysis II.  (Von Bibra.)
Composition of the Bones of a Middle-aged Man.
Femur.      Tibia.  Humerus.  Costa.
Phosphate of lime 
with a little fluo-    59'63    58'95    59'87    55'66
ride of calcium.
Carbonate of lime.  733          7'08     7'76      6'64
Phosphate of magnesia  1'32   1'30  1'09  1'07
Soluble salts..  0'69         0'70     0'72      0'62
Cartilage... 29'70        30'42    29'28    33'97
Fat....  133           155      1'28      2'04
Analysis HII.  (Berzelius.)
Composition of luman Bone.
Phosphate of lime..                                  51 04
Fluoride of calcium....               2.00
Carbonate of lime....                     11 30
Phosphate of magnesia...   116
Soda, with a little chloride of sodium...  120
Cartilage..... 32'17
Vessels....                                           113
Analysis IV.  ( Von Bibra.)
Composition of the Bones of the Lower Animals.
Femur of   Femur of Femur of Humerus of
sheep aged   bull aged horse aged  cat aged
4 years.    4 years.  6 years.   6 years.
Phosphate of lime)
with a little fluo-    55'94    54'07    54'37    59'30
ride of calcium. 
Carbonate of lime      12'18       12'71    12'00    10'69
Phosphate of mag-       1.00        1X42 1t83          1-70
nesia
Soluble salts.      050         0'80     0'70      0.40
Cartilage..     29.68       29'09    27'99    27.21
Fat...       070         1.91     311       0'70
* According to FrEmy, the percentage composition of this portion of
bone is
Carbon.49'21
Hydrogen.                           6'50
Nitrogen.17'86
Oxygen.2514




262                    MORBID BONE.
Vertebra   Humerus   Vertebrae  Vertebrae
of dolphin.  of thrush.   of snake.  of salmon.
Phosphate of lime)
with a little fluo-    52-51      62-65      59-41     36-64
ride of calcium. 
Carbonate of lime         9'37        6-05      7-82      1'01
Phosphate of mag- }       0-98        0-90      1-00       0-70
Soluble salts  1. 24                 0'84       0'73       0'83
Cartilage                33^97      28-02      24'93     21-80
Fat..                    154  6'11  38'82
SECTION III.
Morbid Bone.
712. Certain diseases are found to be always accompanied by remarkable changes in the chemical composition of the bones; the earthy matters being sometimes
so deficient, that they no longer possess the rigidity and
strength necessary for sustaining the weight of the body.
Other variations also are occasionally met with, a few
examples of which are subjoined, the composition being
calculated upon 100 parts.
Analyses of the Tibice of three Rachitic Children. (Lehmann.)
I.       II.      III.
Phosphate of lime.         32-04    26-94    28'13
Carbonate of lime.  401       4-88     3'75
Phosphate of magnesia...  098        0'81     0-87
Chloride of sodium...  021       027       0'28
Soda....  054        0'81     0'73
Cartilage... 54-14    60-14    58-77
Fat....                  584      6-22     6-94
Analyses of Bone in Osteomalacia.  (Pri'sch.)
Vertebra.  Costa.
Phosphate of. lime.                            13'25    33-66
Carbonate of lime.                              5-95  4'60
Sulphate of lime and phosphate of soda.         0'90     0'40
Cartilage..... 74-64 49-77
Fat..    526 11-63
Analyses of C'arious Bone.  (TValentin.)
Vertebrfe of a
man aged 20.
Phosphate of lime.... 33-914      34-383
Carbonate of lime...        7'602       6-636
Phosphate of magnesia...  0-389         1'182
Chloride of sodium                       3 157 -     1.919
Carbonate of soda....  0-118 
Organic constituents.... 54'830       55-880




EXAMINATION OF MIXED ANIMAL FLUIDS. 263
Analysis of Necrotic Bone of a Middle-aged Man. (Von Bibra.)
Phosphate of lime with a little fluoride of calcium    72'63
Carbonate of lime... 403
Phosphate of magnesia..               193
Soluble salts..                     061
Cartilage..                    1958
Fat......... 1-22
CHAPTER X.
EXAMINATION OF MIXED ANIMAL FLUIDS.
713. ON account of the great number and variety of
organic substances which may enter into the composition
of such a mixture as we are now considering, it is altogether impossible to lay down any general and consecutive scheme of experiments, which shall comprise all
even of the more commonly occurring organic compounds.
All that I shall attempt, therefore, in the present chapter,
is to describe very briefly the methods of detecting the
presence of a few of the substances which are most frequently met with in organic liquids, and which are of
the most practical importance to the pathologist and the
physician.
714. The color, consistence, and general appearance of
the fluid should be first carefully observed, as the presence of many substances, such as blood, mucus, fat,
fibre, &c., may often be readily detected, even with the
naked eye. Should any solid or semi-solid r4atter, be
held in suspension in the liquid, or be found as- a sediment at the bottom, it should be separated, either by
decantation, or by filtering through fine muslin or paper.
715. The matters thus separated from the fluid may be
reserved for examination under the microscope, and also,
if necessary, with other tests. The following substances,
among others, may in this way be readily detected:muscular fibre and other organized tissues; epithelium
(328); mucus and pus granules (329); fat and milk globules (325, 632, 633); infusoria of several kinds; besides




264        FIBRIN-ALBU MEN    CASEIN.
various amorphous and crystalline substances, many of
which may at once be recognized by their peculiar form
and appearance (315-332, &c.).
716. The liquid may first be tested with litmus and
turmeric paper, since the behavior of several of the substances about to be noticed, with reagents, will be found
to vary according as the liquid containing them is acid,
alkaline, or neutral.
717. The specific gravity may also be ascertained,
when it can conveniently be done, as a knowledge of the
density of the fluid will serve to furnish some indication
of the amount of solid matter held in solution (279).
Fibrin.
718. When fibrin, in the soluble state, is contained in
a liquid, it gradually undergoes spontaneous coagulation,
and separates from the solution, forming a more or less
firm coagulumn or jelly: and if other matters are held in
suspension in the liquid previous to the coagulation, they
are usually entangled in it-a familiar instance of which
is afforded by the coagulation of blood (473). The more
important peculiarities of fibrin have already been noticed
in paragraphs 472 to 481.
Albumen.
719. When albumen is suspected to be present in solution, the clear liquid is to be gently boiled for a few
minutes; if coagulation takes place, and if the precipitate
thus occasioned does not disappear on the addition of a
few drops of nitric acid, albumen is present. If the mix.
ture is lkaline, it should be neutralized with nitric acid
previous to boiling, since any excess of alkali would tend
to retain the albumen in solution, and thus prevent the
coagulation.  For further particulars respecting albumen, and its behavior with reagents, see paragraphs, 183,
235, 466, &c.
Casein.
720. Casein may be recognized by its forming a white
curdy precipitate, when the solution containing it is neutralized or very slightly supersaturated with acetic acid.




PYIN-PUS-MUCUS.                   265
It redissolves, however, if the acid be added in decided
excess. If the liquid is slightly acid to test paper, caseia
hardly need be looked for, since it is not soluble in acid
solutions, unless the acid is present in considerable excess.
It may be distinguished from albumen by not coagulating when heated; it forms, however, a thin, insoluble
pellicle on the surface when exposed to the air while hot
-of which a familiar example is afforded in the s1cin of
boiled milk. If casein be dissolved in acetic or any other
acid, it is precipitated on the addition of ferrocyanide of
potassium, thus resembling the other modifications of protein (625).
Pyin.
721. This substance, which appears to be identical with
the so-called tritoxide of protein,* and is consequently
closely allied to the other protein compounds (472), may
be recognized by its throwing down a precipitate with
acetic acid, which does not redissolve in an excess of the
acid. A solution of alum also causes a white precipitate,
insoluble in excess; in which respect pyin differs from
glutin and chondlin (725, 726). Unlike most of the protein compounds, it is not precipitated by ferrocyanide of
potassium.
Pus.
722. When pyin has been detected in a liquid, it is
not improbable that, on examination with the microscope,
the peculiar pus granules (678) will also be found to be
present, since pyin is one of the characteristic constituents
of the fluid portion of pus (676). The principal characters of this substance, together with the modes of its detection, have been already described in paragraphs 153,
247, 674, &c.
Mucus.
723. If much mucus is present, it gives to the mixture
a more or less tenacious and ropy consistence, which is
very characteristic. Under the microscope the peculiar
* This name is conferred by Mulder upon the soluble substance
obtained by boiling any of the protein compounds for several hours
with water.
23




266           GELATINE —CHONDRIN.
mucus corpuscles, as well as the fragments of epithelium
which usually accompany them, will also probably be
apparent (Fig. 5); and these, in conjunction with the
ropiness above alluded to, are generally sufficient evidence of the existence of mucus. When present only
in minute quantity, and especially when mixed with pus,
it is often extremely difficult, if not impossible, to identify it with any degree of certainty. (See also paragraphs
31, 99, 210, 660, &c.)
Gelatine; Chondrin.
724. These substances, which are formed by boiling
the cartilaginous tissues in water, closely resemble each
other in many respects; and their hot aqueous solutions
become gelatinous on cooling. Glue, isinglass, and the
several varieties of gelatine, met with in commerce, are
all modifications of these principles. Both gelatine and
chondrin  are immediately precipitated, even in very
dilute solutions, by a solution of tannin. They are not
precipitated by ferrocyanide of potassium; in which
respect they differ from the protein compounds. They
are thrown down from their strong solutions by alcohol, in the form of a white tenacious precipitate; and
creasote causes their solutions to become turbid and
gelatinous.
725. Gelatine, which is obtained by boiling in water
for some hours the cartilage of bone, the tendons, skin,
&c., is characterized by giving with acetic acid a very
slight precipitate, which readily redissolves in an excess
of the acid. A solution of alum gives with gelatine no
precipitate; or if a slight opalescence is occasioned, it
disappears on the addition of a further quantity of the
precipitant.
726. Chlondrin, on the other hand, which is formed by
boiling in water any of the permanent cartilages, as those
of the larynx, ribs, &c., is immediately precipitated by
acetic acid, and an excess of the acid does not redissolve
it. Alum, too, causes a precipitate, which, however,
readily dissolves when the salt is added in excess. The
solubility of chondrin in a solution of alum serves to distinguish it from pyin (721).




BLOOD-BILIARY  MATTER-UREA.    267
Blood.
727. The color which it imparts to any liquid with
which it is mixed, is usually almost sufficient evidence
of the presence of blood, unless the quantity is very
small. The red corpuscles may also, in most cases, be
detected under the microscope, more or less altered in
form and size by the action of the fluid in which they
float (456, 583).  When blood is present, albumen also
will be found dissolved in the liquid, unless it has been
previously coagulated by heat or otherwise; it may be
detected by the application of heat, and nitric acid, in
the manner described in paragraphs 235, 236, &c.
Biliary Matter.
728. Biliary matter, if present in any considerable
quantity, generally communicates a more or less decided
brown or yellowish color to the liquid, and also a peculiar bitter taste. It may be identified by means of Ileller's and Pettenkofer's tests, described in paragraphs 149
and 151. If these fail to detect it in the fluid, a little of
the latter may be evaporated nearly to dryness on a
water-bath, and a strong aqueous solution of the residue
tested as before.
Urea.
729. This substance may be detected in organic liquids
in the following manner: The portion of the organic
mixture intended for the examination, is evaporated to
dryness at a gentle heat on a water-bath, and the dry
residue treated with alcohol, which will dissolve out any
urea that might be present, together, probably, with some
other of the matters with which it is associated. The
alcoholic solution is then evaporated to dryness, and the
dry extract digested with a very small quantity of moderately warm water; which will readily dissolve out the
urea. The aqueous solution thus obtained is then mixed,
after filtering, with pure nitric acid, in the manner described in paragraph 16, and then cooled by means of a
freezing mixture; when, if urea is present, delicate crystals of the nitrate (Fig. 2) will gradually appear.*  When
* Urea may be detected in this manner in blood, chyle, and lymph,
as well as ill urine.




268             KREATINE-INOSITE.
the quantity of urea is very small, the microscope may be
employed to detect any traces of the crystalline nitrate,
and some other precautions must be observed, which
have been described in paragraphs 181, 184, 341, &c.
Kreatine.
729a. For the detection of kreatine in an organic mixture, the solid portion should be divided as finely as possible, the whole dried upon the water-bath, and digested
with hot alcohol. The alcoholic solution having been
pressed out, is evaporated to dryness on the water-bath,
the residue treated with water, the solution precipitated
by acetate of lead (not added in excess) and filtered. The
filtrate is saturated with sulphuretted hydrogen, to precipitate the lead, and the solution separated from  the
sulphide of lead is evaporated to a syrup and set aside
for some days, when kreatine will crystallize out and
may be recognized by the characters described above,
especially by converting it into kreatinine and obtaining
the crystalline precipitate with chloride of zinc.
Inosite.
729b. The presence of inosite may be ascertained (in
an aqueous infusion of bullock's lung, for example), by
acidulating with acetic acid, coagulating the albumen by
heat, and precipitating the filtered liquid with acetate of
lead. The filtrate from this precipitate is mixed with.
tribasic acetate of lead, which will throw down any inosite if present. The precipitate is suspended in water,
decomposed by sulphuretted hydrogen, the liquid filtered
from the sulphide of lead, evaporated to a very small
bulk, mixed with four volumes of boiling alcohol, filtered
if necessary, and set aside for twenty-four hours. If no
crystals of inosite have then been deposited, ether is
added by degrees until a permanent milkiness is produced on agitation. The liquid is again set aside, when
inosite will crystallize out, and may be identified by treating it with ammonia and chloride of calcium, and slowly
evaporating to dryness, when a rose color will be produced.




CHOLESTERIN AND SEROLIN —MILK.   269
Fat.
730. When any considerable amount of fatty matter
is present in an aqueous mixture, it may be readily detected with the naked eye, and still more delicately under
the microscope, by the appearance of oily or fatty globules floating on the surface. When, however, the quantity is very small, or, owing to other circumstances, no
appearance of fat is to be seen; a little of the mixture
suspected to contain it, is to be evaporated nearly to dryness on a water-bath, and the residue digested with a little warm ether, which will readily dissolve any traces of
fatty matter that may be present. On evaporating the
ethereal solution on a water-bath, the oil or fat will be
left as a residue, and may be identified by its possessing
the well-known physical characters of fatty matters (158).
731. The saponifiable fats most commonly met with
in animal fluids are, oleine (Cl4H,04012), stearine (C,,141110
0,2), margarine (C,08H,04012), and butyrine. The degree
of hardness or of oiliness, and the temperature to which
the fatty matter requires to be raised before it melts,
serve to furnish some indication as to the relative amounts
of the solid stearine and the oily oleine. Butyrine may
generally be detected by the peculiar smell which it gradually acquires, resembling that of rancid butter.
Cholesterin and Serolin.
732. If either of these substances are present, they
will have been dissolved by the ether (730), together with
any other fatty matters that may be contained in the
liquid. They may be separated from the other fats by
digestion with a solution of potash, which will dissolve
out the saponifiable fats, and leave the cholesterin and
serolin unaffected (596).  These may be distinguished
from each other by their different fusing points, that of
cholesterin being 2930, while that of serolin is as low
as 970~.
Milk.
733. The well-known physical characters of milk are
generally sufficiently apparent to lead to its detection,
unless largely diluted with other matters. When any
23*




270             SUGAR-AMMONIA.
doubt exists as to its presence, a drop of the liquid may
be examined under the microscope for the milk globules
(632); and the clear liquid, after filtration, may be tested
with acetic acid for casein (623); the existence of which,
in any fluid, is strong evidence of the presence of milk.
The residue left by evaporating the liquid to dryness,
may be tested for fat also, by digestion with warm ether,
and evaporating the ethereal solution on a water-bath
(730).
Sugar.
734. The most convenient test for the presence of
sugar is that known as Trommer's, which has already
been fully described in paragraphs 122 to 124. Maumen6's (125), and the fermentation test (128), may also,
in many cases, be employed with advantage; and, indeed,
it is always more satisfactory to confirm the results of
Trolnmer's experiment, by applying also the fermentation test; since the suboxide of copper may be sometimes
produced by certain other organic substances, even when
no sugar is present.  If the sugar is present only in very
minute quantity, it may be advisable to evaporate the
liquid to dryness on a water-bath, and redissolve the
soluble portion of the residue, including the sugar, in a
small quantity of hot water, in the manner described in
the process for detecting sugar in the blood (606). The
strong aqueous solution may then be examined by
Trommer's, Maumen6's and the other tests.
735. When cane sugar is suspected to be present, the
solution should first be boiled for a few minutes with
dilute sulphuric acid before the application of Trommer's
test, in order to convert it into grape sugar; since the
cane variety does not otherwise produce the same characteristic results.
Ammonia.
736. This substance, which is so constantly to be met
with in animal fluids, as one of the results of the decomposition of nitrogenous compounds, may be readily
detected, even when present in very small quantities.
A portion of the liquid is mixed in a test-tube with a
little caustic potash, or, still better, with caustic baryta




URIC (OR LITHIC) ACID.             271
(note to 38), and warmed. The ammonia, if present, is
thus disengaged, and may be detected by the smell, or,
still more delicately, by holding at the mouth of the tube
a glass rod moistened with dilute hydrochloric acid, when
white fumes of chloride of ammonium will be distinctly
visible.
737. If the ammonia is present only in minute quantity, a little of the suspected liquid may be mixed with
a few drops of dilute sulphuric acid, in order to fix the
ammonia, and then concentrated by evaporation at a
gentle heat on a water bath; the concentrated liquid may
then be supersaturated with potash or baryta, and examined in the manner above described.
Uric (or Lithic) Acid.
738. When an organic mixture is suspected to contain uric acid, it may, if free from albuminous matter, be
acidified with a few drops of hydrochloric acid, and
allowed to stand a short time. The uric acid will gradually separate in the form of minute crystals (20), which
may be examined under the microscope, and also tested
with nitric acid and ammonia, in the manner described
in paragraph 23. If any albuminous matter is mixed
with the liquid, the latter is to be evaporated to dryness
on a water bath, and the residue digested with a dilute
solution of caustic potash. The alkaline solution is then
supersaturated with a decided excess of hydrochloric
acid, which will throw down the uric acid in the form of
a crystalline precipitate. If the quantity is small, a drop
of the liquid may be mixed with the acid on a strip of
glass, and examined for the characteristic crystals under
the microscope (318).
738a. Another process, which is sometimes more convenient than the above, consists in mixing the solution
with acetate of lead as long as it yields a fresh precipitate, filtering, and adding tribasic acetate of lead. On
standing, urate of lead will be precipitated, which must
be washed, suspended in water, and decomposed by sulphuretted hydrogen. The solution is boiled, filtered from
the sulphide of lead, and evaporated to a small bulk. On
cooling, crystals of uric acid are deposited.




27X2      SYSTEMATIC EXAMINATION  OF
739. The principal characters of uric acid, and the
methods of detecting annd estimating it in the urine, have
been already noticed in the several chapters of Part I.
Systematic Examination of Mixed Fluids for the Proximate
Constituents of Animal Bodies.
Some of the proximate constituents of the solids and
fluids of the body, such as fibrine and gelatine, are recognizable by their characteristic external appearance, but
the greater number give no indication of their existence
unless specially sought for, so that it is desirable to follow
some systematic plan of examination in order that they
may not be overlooked. The solid organs must be divided as minutely as possible, and digested for some
time in tepid water.
The reaction of the liquid to test-papers having been
recorded, it is acidified, if necessary, with acetic acid, and
heated on a water-bath in order to coagulate albumen
which is then filtered off. On allowing the hot filtrate
to stand for some time, uric acid will crystallize out as it
cools. The solution is then very nearly neutralized with
potash, and acetate of lead added, to precipitate sulphuric
and phosphoric acids, as well as coloring and extractive
matters; the filtered liquid is mixed with an excess of
tribasic acetate of lead. The precipitate, which may contain inosite, is decomposed by sulphuretted hydrogen and
the solution evaporated till a portion becomes permanently turbid when mixed with alcohol, the whole is then
mixed with an equal volume of alcohol, heated till the
turbidity disappears, and set aside for a day or two that
the inosite may crystallize out.
The filtrate fronm the precipitate produced by tribasic
acetate of. lead is now mixed with a slight excess of ammonia, and any precipitate is collected, decomposed by
sulphuretted hydrogen, and the solution, after evaporation, examined for sugar.
The liquid filtered from the precipitate produced by
ammonia is treated with sulphuretted hydrogen, filtered
from the sulphide of lead, evaporated to a small bulk
upon the water-bath, and tested, with oxalic acid (14),
for urea.




MIXED  FLUIDS.                    273
The solution is then evaporated to a syrup, and mixed
with moderately strong alcohol to precipitate the oxalates
of the alkalies. The alcohol is evaporated, the excess of
oxalic acid removed by the careful addition of lime-water,
and the filtered solution evaporated till an equal volume
of absolute alcohol renders it permanently turbid.  It is
then mixed with alcohol and set aside for a day or two,
when taurine will be deposited in crystals.
The alcoholic solution is again evaporated on- the
water bath, and if the residue is much colored, it may
be dissolved in a little water and boiled with hydrated
oxide of lead, the filtered  solution  being afterwards
treated with hydrosulphuric acid to remove the lead,
and evaporated to a syrup. On allowing this to stand
for some time, ckreatine and leucine* may crystallize out.
They may be washed with cold absolute alcohol, and
identified, the kreatine by its convertibility into kreatinine, and the leucine by the woolly sublimate which it
furnishes when heated in a tube. The mother liquor
from these may contain kreatinine, recognizable by its
behavior with chloride of zinc.
* Leucine (C,211,3N04) and tyrosine (C,,H,,NO6) have been detected
in the spleen, pancreas, and liver, and the former also in the lungs,
and both have been observed in the urine in disease. Tyrosine is
identified by digesting it with sulphuric acid, diluting with water,
heating the solution with carbonate of lime, filtering, and adding perchloride of iron, which produces a violet color. Protonitrate of mercury gives a red precipitate and a pink liquid when added to a solution of tyrosine.




P ART V.
THE DETECTION OF POISONS IN ORGANIC
MIXTURES, &c.
CHAPTER  I.
ARSENIC.
IT is impossible to insist too strongly on the necessity
for the most careful examination into the purity of all
the substances employed in the detection of poisons. No
evidence with respect to the presence of a poisonous
substance can be regarded as perfectly conclusive, unless
the reagents employed have been tested, in the same
quantities, and by the same processes, as were employed
in detecting the poison, without affording any indication
of its presence.
Moreover, if any particular substance, though not a
poison, be detected in the course of the examination,
with all the bearings of which upon the tests employed
the investigator is not perfectly familiar, the same series
of operations should be conducted with that substance,
to ascertain whether it might lead to error.
740. Although all, or nearly all, the compounds of
arsenic appear to be more or less intensely poisonous, I
shall here allude especially to the detection of arsenious
acid (AsO,); since in the vast majority of cases in which
arsenic is taken, whether criminally or accidentally, it is
in the form of arsenious acid, or, as it is often called,
oxide of arsenic, or white arsenic. The experiments
which I am about to describe will serve, however, for the
most part, equally well for identifying the presence of
arsenic in other forms of combination than that of arseni



IDENTIFICATION  OF ARSENIOUS ACID.  275
ous acid; so that, if the processes are carefully conducted,
the risk of any traces of the metal escaping detection is
very small.
741. When the presence of sulphide (or sulphuret) of
arsenic (AsS3) is suspected, the substance supposed to
contain it may be first examined for any particles of
yellow powder; which, if present, should be mixed, when
dry, with a little black flux, or with a mixture of dry
carbonate of soda and charcoal, and heated in a small
German glass tube, closed at one end; when, if it consists
of sulphite of arsenic, a crust of the metal will appear
in the upper part of the tube (743). If no yellow powder
can be detected, the mass in which it is suspected to be
present is to be treated according to the directions given
hereafter.
SECTION I.
Identification of Arsenious Acid when unmixed with other
substances.
742. Place a little of the white powder in a small
tube of German glass, closed at one end, and heat it
gradually in the flame of a
spirit lamp, taking care to warm      Fig. 76.
the upper part of the tube
slightly before heating the arsenious acid. If it is arsenious
acid, it will sublime, and condense in the upper part of the'    -
tube, formino a colorless crys-   
talline sublimate, which, when
examined with a good lens or
microscope, will be found to
consist of beautiful sparkling
octohedral crystals (Fig. 76).      Arsenious Acid.
The size and regularity of the
crystals appear to depend on the slowness with which
the vapor is condensed. If the surface of the glass on
which the condensation takes place is quite cold, the
sublimate is often amorphous, as may be seen by holding




276                    ARSENI C.
a piece of cold glass in the fumes given off by a little
arsenious acid heated on charcoal.*
743. Mix a little of the suspected powder with a large
proportion  of black flux, or of carbonate of soda and
charcoal, which for this purpose should
Fig. 77.   be perfectly dry, and heat the mixture in a
small tube of German glass before the blowpipe.  If arsenic is present, it will be reduced to the metallic state, and sublime into
the upper part of the tube, forming a shining
metallic crust (a, Fig. 77).  The part of the
tube which contains the crust may then be
filed off, wrapped in a piece of strong paper
and broken, the fragments of the crust being
placed in another tube, and again heated.
The reduced metal will in this way be reconverted into arsenious acid, crystals of which will condense in the cool part of the tube (742).
744. Make a solution of some of the powder by boiling
it for some minutes with water, in which arsenious acid
is sparingly soluble, and apply to separate portions of
the solution the following tests. (See also 745 and 749.)
(a) Acidify a portion of the solution with a drop or
two of hydrochloric acid, and pass a current of hydrosulphuric acid gas (sulphuretted hydrogen) through the
liquid, until it smells distinctly of the gas. If arsenious
acid is present, a bright yellow precipitate of sulphide
(AsS3) will be thrown down, very easily dissolved by
am monia.
(b) Add to the second portion of the solution a few drops
of arnmonio-nitrate (AgO,NO.5,2NNH3) of silver. If arsenious acid is present, a canary colored precipitate of arsenite
of silver (3AgO,AsO3) will be thrown down, which is
soluble in nitric acid and also in ammonia.
(c) Test a little of the solution with ammonio-sulphate
(Cu,003f2N1f3,HO) of copper.  This will cause, with
* For much valuable information with respect to the detection of
arsenious acid with the aid of the microscope, we are indebted to Dr.
Guy's minute investigations, an abstract of which is given in his
Principles of Forensic Medicine, 2d edition.




MARSH' S TEST.                  277
arsenious acid, a pale green precipitate of arsenite of
copper (2Cu0,HO,AsO3).
Marsh's Test.
745. Arrange a wide-mouthed bottle, of six or eight
ounces' capacity, with tubes as shown in the annexed
figure; the tube d being of hard German glass. Place
in it a few fragments of zinc, and add a little dilute sulphuric acid, consisting of one part of the strong acid
to six or eight of water.
When the hydrogen has                  Fig. 78.
been coming off about five,
minutes,* apply a light to   e
the gas as it issues from         _            ~
the aperture at e, and hold
over it, or rather in it, a
clean  porcelain  crucible
lid, in  order  to  prove
whether any traces of arsenic are contained in the
zinc or acid employed, in
which case a more or less
distinct arsenical stain would be produced. If the materials are thus found to be pure, a little of the solution
of the supposed arsenic is to be introduced through the
tube b.
746. Again apply a light to the jet of gas at e, and
hold in the flame a clean porcelain crucible lid. If arsenic
is present, dark spots of the metal will be deposited on
the surface of the porcelain, wherever it has been allowed
to enter the flame. A few of these stains may be prepared and tested in the following manner, in order to
prove whether they really consist of arsenic, and not of
antimony; which latter, if present, would produce stains
very similar in appearance to those of arsenic.
(a) Apply the heat of a spirit lamp to one of the spots.
* This interval must be allowed to elapse, in order that the whole
of the common air in the apparatus may be expelled before the light
is applied; since a mixture of hydrogen and common air is highly
explosive.
24




278                    ARSENIC.
If arsenic, it will readily volatilize, and a slight smell,
resembling garlic, will probably be perceptible.
(b) Moisten one of the spots with a drop of yellow
hydrosulphate of ammonia, containing an excess of
sulphur. If it consists of arsenic it will remain undissolved for some considerable time; while if it were
antimony, it would immediately dissolve.
(c) Add a drop or two of a solution of chloride of lime
(CaOCl) to one of the stains.  If it consists of arsenic it
will immediately dissolve.
747. Hold over the flame a short wide test tube (Fig.
79), so as to collect the fumes of arsenious acid formed
during the combustion of the arseniuretted hydrogen.
The arsenical sublimate may be dissolved in hot water,
and the solution tested as described in paragraph 744,
a, b, and c. (See also 749.) The sublimate formed in the
tube by antimony, under
Fig. 79.          the  same  circumstances,
would, on  the  contrary,
prove  quite  insoluble in
water.
748. Apply  the heat of
a spirit lamp to the tube at
the point d' (Fig. 78), and
observe the formation of a
dark ring of metallic arsenic*  inside the tube, a
little in advance of the
heated point. The arsenic thus deposited may be volatilized backwards and forwards in the tube, by applying
the heat of a spirit lamp (765, a). If the tube be then
disconnected from the bottle, and the arsenic volatilized
in it while filled with atmospheric air, the metal will
gradually become oxidized and converted into arsenious
acid, crystals of which will appear in the cool part of the
tube.
For testing very small quantities ot a substance sus* In consequence of a secondary decomposition between the zinc
and sulphuric acid (Fordos and G61is) a little sulphuretted hydrogen
is sometimes formed, which gives rise to a yellow ring of sulphide of
arsenic by the side of the metallic ring.




MARSH'S TEST.                 279
pected to contain arsenic, it is advisable to employ a much
smaller apparatus (Fig. 80) than that above described. A
two-ounce bottle may be used, or even a short wide testtube capable of containing about half an ounce of liquid.
The tube through which the gas escapes should be drawn
out at the extremity, so as to form a very narrow tube
about two inches long. In such cases it is not advisable
to run the risk of allowing any arsenic to escape, on
which account the shoulder of the tube should be heated
Fig. 80.
with a spirit lamp before the suspected solution is introduced, when a metallic deposit will be formed in the
narrow portion of the tube if any arsenic be present. By
employing a long tube constricted at intervals, and heating each of the wide portions of the tube, several metallic
deposits may be produced at the same time, and may be
made the subjects of various confirmatory experiments.
When a very small apparatus is employed, the zinc should
be free, not only from arsenic, but from all other metals,
so that the evolution of hydrogen may be slow and
uniform.
If Marsh's apparatus be immersed in a considerable
volume of cold water whilst in use, to prevent a great
rise of temperature, it is not necessary, even in very
minute testing, to dry the gas, as is sometimes recommended.
The metallic crusts obtained in the tube should be
examined by the following confirmatory tests.




280                   ARSENIC.
(a) Place the piece of tube with the deposit in a small
hard glass tube, and apply the heat of a spirit lamp; the
crust will gradually disappear, and crystals of arsenious
acid (742) will be deposited on the cooler part of the tube.
(b) Place the tube and deposit in a little water contained in a small test tube, and add two or three drops of
yellow sulphide of ammonia; an arsenical crust should
not dissolve even on shaking for some little time. Pour
off the liquid, wash the tube several times with distilled
water, and add some clear solution of chloride of lime
(bleaching powder), by which the crust should be dissolved
on agitation.
(c) Boil the tube containing the metallic deposit in a
few drops of pure nitric acid, in a small test-tube; when
the crust is dissolved, rinse the solution into a very small
porcelain dish, and evaporate just to dryness over the
lamp. The residue of arsenic acid (AsO5) which should
be left, would become moist on exposure to the air for a
few minutes, would dissolve easily in water, and the
solution would give a brown-red precipitate of arseniate
of silver (3AgO,AsO5) on adding nitrate or ammonionitrate of silver. Should no precipitate be obtained,
perhaps a little free nitric acid may have been left, in
which case, a glass rod dipped in dilute ammonia will
produce the precipitate.
Beinsch's Test.
749. Before applying this test, the simplest by which
minute quantities of arsenic can be detected, great care is
required to insure the absence of that metal in the
hydrochloric acid and the copper necessary for its execution. As it is not easy to procure ordinary copper not
containing a little arsenic, it is better to employ the metal
deposited by the electrotype process from a solution of
sulphate of copper which has been carefully purified by
re-crystallization. In order to test the copper and hydrochloric acid for arsenic, the following experiments should
be made.
(1) Mix one ounce of the hydrochloric acid with four
ounces of water, boil it in a small flask and introduce a
small strip of the copper; boil for fifteen or twenty




REINSCH'S TEST.                  281
minutes, and if the copper remain perfectly bright, the
hydrochloric acid may be deemed sufficiently pure.
(2) Cut a square inch of the copper into small strips
and heat them in a small tube of hard glass, first with
the flame, and afterwards with the blowpipe, to see if any
crystals, of arsenious acid are deposited.
(3) Cut two square inches of the copper into strips,
place them in a shallow dish, moisten them with the
hydrochloric acid, and leave them for some time exposed
to the air; add a little more hydrochloric acid from time
to time, until all the copper is dissolved (which will require many hours' exposure); pour the' solution into a
small retort, add about half its bulk of hydrochloric acid,
and distil over about two thirds at a moderate heat, condensing the vapors by passing them through a tube kept
cool by wet filtering-paper. Dilute the distilled liquid
with four times its bulk of water, and boil it with a strip
of copper, which should remain untarnished if no arsenic
be present.
In this test the arsenical copper is converted into subchloride of copper, by favor of the oxygen of the air,
Cu,+ HC1 + O= Cu2Cl + HO.
The arsenic passes into solution as terchloride (AsCI3)
together with the subchloride of copper which is soluble
in hydrochloric acid. On distilling, the terchloride of
arsenic passes over with the acid.
The hydrochloricacid employed in Reinsch'stest should
also be free from sulphurous acid, which may be detected
by dissolving a little zinc in the dilute acid, and conducting the gas into solution of acetate of lead in which
a black precipitate of sulphide of lead (PbS) would be
produced if any sulphurous acid were present.
In order to apply this test, acidify a little of the aqueous solution of the substance suspected to contain arsenic,
with a few drops of pure hydrochloric acid, and boil in
it two or three strips of clean copper foil. If arsenic is
present, it will be deposited in the metallic state* on the
* Lippert has shown that this deposit is not pure metallic arsenic,
but an alloy containing 32 per cent. of arsenic and 68 of copper
(CuAs).
24*




282                    ARSENIC.
surface of the copper, and may be proved to be arsenic
in the following manner:(a) Wash the copper strips, and dry them  by gentle
pressure between folds of filtering-paper, or by warming
them on a water-bath; when dry, place them in a small
clean and dry tube of German glass, closed at one end,
and apply heat, first with the flame alone, and afterwards
with the blowpipe. The arsenic will volatilize; and
becoming oxidized while in contact with the air, arsenious
acid will condense in the upper part of the tube, forming
a crystalline sublimate, which may be examined with a
lens (742).
(b) Dissolve the sublimate obtained in a in a little hot
water, and apply to the solution the tests described in
paragraph 744. If it be very minute, it may be dissolved
by boiling with a few drops of nitric acid, and tested as
in 748c.*
SECTION II.
Detection of Arsenic in the presence of Organic Matter.
750. The cases in which arsenic has to be detected in
the presence of organic matter may be classed under
three heads, the first including pretty clear and homogeneous liquids, such as beer, milk, and urine; the second,
such thick heterogeneous mixtures as gruel, pudding,
and the contents of the stomach or intestines; and the
third the solid organs of the body, such as the liver, in
which arsenic is generally to be detected after death by
poisoning.
Detection of Arsenic in Organic Liquids which are pretty clear
and homogeneous.
751. When the investigation has any judicial interest,
the quantity of the liquid should be carefully recorded,
and every portion which is taken for a separate experiment must be measured, so that, if the poison be detected,
the analyst may be able to give an opinion respecting its
quantity.
- * Arsenic is much more difficult to detect by Reinsch's test when
in the state of arsenic acid. It then requires long boiling with copper
in the presence of a very large excess of hydrochloric acid.




ARSENIC IN ORGANIC MATTER.             283
A portion of the liquid may then be be acidified with a
little pure hydroehloric acid (the purity of which has
been previously ascertained), and then boiled with two
or three small strips of tested copper foil. If arsenic is
present, it will probably be deposited, in the course of a
few minutes, upon the surface of the copper, and must
be treated in the manner presently to be described. It
must not, however, be considered certain that no arsenic
is contained in the liquid until after boiling the mixture
for half an hour, or even longer, when, if no stain is
produced, which, on examination, gives indications of
arsenic, it may safely be concluded that no trace of the
metal is present.
It occasionally happens that a little fatty animal matter
is deposited on the surface of the copper during the
boiling. When this is the case, the copper should be
boiled with a little ether or alcohol, in order to dissolve
it, before being exposed to heat in the tube.
752. The copper strips must now be heated in a small
clean and dry tube, closed at one end; when if any
arsenic has been deposited upon them, a crystalline sublimate of arsenious acid will appear in the upper part of
the tube. If, on examination with a lens, the sublimate
is found to exhibit the characteristic crystalline form and
appearance of arsenious acid (742), there can scarcely be
a doubt of the existence of arsenic. Proceed further as
in 749 (b).
753. In most cases, when no arsenic has been thus
reduced upon the copper, it may be inferred that no
appreciable amount of that metal is present, but should
arsenic be detected, the analyst should, if possible, proceed to obtain further evidence of its presence by other
methods.
If the liquid be not very viscid and liable to froth, it
may be acidulated with a little pure sulphuric acid, filtered, if necessary, and subjected to Marsh's test (745).
If frothing should take place to any inconvenient extent,
a drachm or two of alcohol may be poured down the
funnel tube in order to arrest it.
In the case of viscid liquids to which Marsh's test cannot be applied, it is recommended to evaporate them to




284                    A RSE NIC.
a small bulk upon a water-bath, to acidify strongly with
pure hydrochloric acid, and to add chlorate of potash, in
small quantities, until the liquid becomes so limpid as to
admit of filtration. The heat of the water-bath is continued until the smell of chlorine has in great measure
disappeared, and the liquid, if necessary, filtered. The
clear filtrate may be tested, either by Marsh's process
(745), or by electrolysis.
Electrolytic test for Arsenic.-This test depends upon
the circumstance that when a pretty powerful galvanic
current is made to traverse an acid liquid containing
arsenic, arseniuretted hydrogen is evolved at the negative terminal, together with the hydrogen of the decomposed water.
To construct the apparatus (Fig. 81) for this test, a two
ounce bottle, with a moFig. 81.            derately  wide  mouth,
is selected, and a filemark  made at a little
distance from the bottom, so that it may be
extended into a crack
by  placing  a  red-hot
wire against it, and led
round the bottle so as
~'(           to cut off the bottom.
The edges having been
+        IIi  -   smoothed with a file, or
by grinding on a wet
stone, a pretty  deep
groove is filed round
the bottle at about half
an inch from the edge.
A piece of wet parchment-paper* is doubled down over the bottom of the
bottle, and secured by a piece of stout platinum wire, for
which the groove has been cut in the glass. A perfo* Parchment paper is now commonly sold. It may be made by
immersing white blotting-paper for an instant in a cold mixture of the
strongest oil of vitriol with half its volume of water, and rapidly washing.




ELECTROLYTIC TEST,FOR ARSENIC.   285
rated cork is inserted in the month of the bottle, provided
with a narrow funnel tube, somewhat drawn out at the
extremity, which should nearly touch the paper diaphragm, and with a small tube bent at right angles, for
the exit of the gas. A strip of platinum foil cut into
the shape of a spade is secured between the cork and the
neck of the bottle, so that its broad end, hanging down
within the bottle, may nearly touch the diaphragm, the
other end projecting an inch or two beyond the neck of
the bottle. The narrow part of this strip may be about
a quarter of an inch wide, and the broader part an inch
square. The bottle is placed in a cylindrical jar not
much wider than itself, and not so flat at the bottom as
perfectly to close the bottom of the bottle; between the
side of the jar and the bottle, a second strip of platinum
foil, similar to the above, is suspended, so as nearly to
touch the bottom of the jar. With the bent tube provided for the egress of gas there is connected, by means
of a small caoutchouc tube, a rather thick narrow tube,
of very infusible glass, drawn out to a very narrow point,
about two inches long; this tube must be supported
across the ring of a retort stand.
The apparatus is charged with a mixture of two
drachms of pure sulphuric acid, and six drachms of
water, half of the mixture being poured down the funnel,
and the remainder into the outer jar. The latter is then
immersed in a basin of water to prevent too great a rise
of temperature, and the two strips of platinum are connected with the terminal wires of a galvanic battery,*
the wire proceeding from the zinc extremity being united
to the strip within the bottle, and that from the platinum,
copper, or carbon end with the strip which dips into the
outer jar. Ten or fifteen minutes having been allowed
for the expulsion of the air by the hydrogen evolved
from the platinum in the bottle, a small spirit flame is
applied to the shoulder of the drawn-out tube, so as to
heat it to dull redness, at which it should be kept for
about a quarter of an hour; if no ring of arsenic or sul* Five or six Grove's cells are very suitable for the purpose, but of
course any battery which decomposes acidulated water pretty briskly
will answer.




286                    ARSENIC.
phide of arsenic is then visible in the narrow point of
the tube, showing that the sulphuric acid is pure, the
solution to be tested for arsenic* is poured slowly down
the funnel tube, care being taken to avoid the introduction of air-bubbles. If much froth should now make
its appearance, a drachm or two of alcohol may be
poured down the tube. If no deposit of arsenic or of
(yellow) sulphide of arsenic be visible after ten minutes,
half a drachm of a strong solution of washed sulphurous
acid or of sulphuretted hydrogen is poured in, and the
experiment continued for another quarter or half hour.
If any arsenic be present, either the metallic ring of
arsenic, or a greenish-yellow iridescent ring of sulphide
of arsenic, or both, will be deposited in the narrow part
of the tube.t   The lamp is then  removed, the tube
allowed to cool, and that part which contains the deposit
cut off by a file, and gently warmed in a small test-tube
with a little solution of carbonate of ammonia, in which
the yellow sulphide of arsenic will slowly dissolve. The
tube, with the metallic portion of the crust, is then
washed, and tested according to the directions in 748, a
6 and c.
The liquid which has been subjected to electrolysis is
seldom exhausted of arsenic unless a very minute quantity is present. In order to extract the remainder, the
solution may be mixed with a large excess of a saturated
solution of sulphuretted hydrogen, and heated in a covered
beaker for an hour or two.
753a. The precipitate of sulphide of arsenic mixed
with organic matter is collected on a filter, well washed,
dried, and thrown in small portions into a little nitre
fused in a porcelain crucible, the filter being cut in
pieces and thrown in also. The fused mass (containing
the arsenic as arseniate of potash), when cool, is dissolved
* If this solution contains very much free hydrochloric acid, it is
advisable to dilute it with twice its volume of water.
t If no odor of sulphuretted hydrogen be perceptible at the orifice
of the tube at the end of the experiment, a little more sulphurous
acid or sulphuretted hydrogen should be poured in, lest the liberated
chlorine should have traversed the diaphragm and prevented the
evolution of arseniuretted hydrogen.




ARSENIC IN ORGANIC MIXTURES.              287
in a little water, the solution mixed with chloride of ammonium  and ammonia, filtered, if necessary, and well
stirred with solution of sulphate of magnesia. After
standing for some time, a highly crystalline precipitate
of arseniate of magnesia and ammonia (2MgO,NH40,As
05) will separate, which may be collected on a filter and
washed.
The arseniate of magnesia and ammonia may be easily
distinguished from the phosphate which much resembles
it, by moistening it with nitrate of silver, when it assumes
the characteristic red color of arseniate of silver, whilst
the phosphate becomes bright yellow.  Of course it
might also be dissolved (even after treating it with nitrate
of silver) in hydrochloric acid, and tested by boiling
with hydrosulphuric acid, or by Marsh's test.
SECTION III.
Detection of Arsenic in Organic llixtures containing both
Liquid and Solid Matters; such as the contents of a Stomach,
vomited matters, &c.
754. When the liquid and solid portions of the mixture are found capable of ready separation, either by
subsidence or filtration, it is generally better to examine
each of them separately. When this is not the case, see
paragraph 758.
755. Examination of the liquid portion.-The clear
liquid, after the removal of the solid matter, either by
filtration or otherwise, is to be examined in the manner
described in paragraph 751.
756. Examination of the solid portion. —This should
first be examined for any small lumps of arsenious acid,
which, in cases of poisoning, are- often to be found adhering to the coats of the stomach. These should be carefully picked out, and tested according to the directions
given in paragraphs 742-744.
757. The solid or semi-solid organic matter is then to
be heated on the water-bath with dilute hydrochloric
* In some cases it may be of importance to note the weight of the
solid matter.




288                   ARSENIC.
acid containing about one-tenth of the strong acid. A
part of the acid solution may then be boiled with copper
strips, which are to be dried, and examined for arsenic
in the manner before described (749). The remainder of
the acid solution may be examined by 753, and the undissolved solid portions by 761.
758. When the organic matter is viscid, and incapable
of ready separation into solid and liquid portions (754),
it may be mixed with a little dilute hydrochloric acid,
well stirred together, and boiled; if the solution thus obtained be sufficiently thin, it may be filtered, and dealt
with as in 757, but otherwise it must be treated according to 759.
SECTION IV.
Detection of Arsenic in the Tissues, and in other solid Organic
Matters.
759. In medico-legal investigations as to the presence
of arsenic, it is absolutely necessary in case none of the
poison can be detected in the stomach and its contents,
to examine the various tissues of the body; since the.poison, when introduced into the stomach during life,
becomes gradually absorbed and diffused through the
whole system, and may be found in theblood, urine,
muscles, and viscera, especially the liver.  It is therefore
advisable to examine each of these for the poison; and it
should never be concluded, that because it cannot be detected in the stomach and its contents, none is to be
found in other parts of the body. Should the patient,
however, survive during several days after swallowing
the poison, it is possible that the whole of it may be eliminated from the body; in which case no trace of it will
afterwards be detected.
760. If the solid matters to be examined have undergone putrefaction, the arsenious acid may have been
partly converted into sulphide of arsenic, which is sometimes perceived in bright yellow patches.
761. The solid matter intended for examination* is to
* The part of the body in which the poison is most likely to be
found is the liver, which should always be preferred for these experiments. The pancreas, kidneys, and urine, should also, if possible, be
examined, before deciding on the absence of arsenic.




DETECTION OF ARSENIC  1N THE TISSUES. 289
be cut up and heated on the water-bath for an hour or
two with hydrochloric acid, consisting'of one part of
the strong acid to eight or ten of water. The mixture
is then filtered through fine muslin, in order to separate
the more solid matters; and the clear liquid thus obtained
is concentrated to about half its bulk, by evaporation on
the water-bath, and treated as in 751. The undissolved
solid portions are heated in a porcelain dish, placed upon
a water-bath, with a mixture of six measures of water
and one of hydrochloric acid, to which chlorate of potash
is added in small portions, with constant stirring, until
the solid has disintegrated, and the liquid is fit for filtration. The further treatment is then conducted as in 753.
If a galvanic battery be not procurable, the solution
obtained by means of hydrochloric acid and chlorate of
potash is evaporated to a small bulk, mixed with a strong
solution of washed sulphurous acid,* until it has a decided odor of the gas, heated in a flask placed in a
water-bath, until the odor of sulphurous acid has disappeared, mixed with a large excess of a saturated solution of sulphuretted hydrogen, and digested for some
time at a moderate heat. The precipitate of sulphide of
arsenic, which is never pure yellow, but dingy, from the
presence of organic matter, is collected upon a small filter, washed, and treated as in 753a.
The solution obtained by treatment with hydrochloric
acid and chlorate of potash might also be tested by
Marsh's or by Reinsch's test, but, if the solution is at all
viscous, the frothing is a serious obstacle to the application of the former, and the introduction of copper in the
latter test unfits the solution for further examination if it
should be necessary.
Should it be required to examine for arsenic the organic matter left undissolved by hydrochloric acid and chlorate of potash, it may be dried, mixed with five or six
times its weight of pure nitre, and thrown by degrees
into a red-hot dish or crucible. The deflagrated mass,
which would contain arseniate of potash, is dissolved in
as little water as possible, acidulated with hydrochloric
* To reduce the arsenic acid (As,0) to arsenious acid (AsO,).
25




290                   ARSENIC.
acid, gently heated, and if necessary, filtered. The clear
liquid is mixed with a few drops of solution of sulphate
of magnesia and a considerable excess of ammonia, and
after being well stirred, is set aside for twenty-four hours.
The precipitate will contain the arsenic in the form of
arseniate of magnesia and ammonia (2MgO,NH40,AsO,),
together with earthy phosphates derived from the organic
matter. It is collected upon a filter, washed with dilute
ammonia (pure water dissolves it), and dissolved in as
little dilute hydrochloric acid as possible. The solution
may then be tested either by Marsh's or the electrolytic
test.
761a. Another method which has been found very useful for separating arsenic from organic matters, consists
in drying them upon a water-bath, digesting in a covered
vessel with moderately concentrated hydrochloric acid,
separating the solid matters by filtration, and distilling,
the acid vapor being condensed in a flask containing
water. The arsenic is found in the distillate, having
passed over as terchloride of arsenic (AsCl3) and may
be detected by the ordinary tests.
761b. Detection of arsenite of copper in paper-hangings
and otherfabrics. A very ready method of effecting this
consists in soaking the fabric to be tested in a little solution of ammonia; the blue solution which will be found
if copper is present, is acidulated with hydrochloric acid
and boiled with clean copper (749).
SECTION V.
Quantitative Determination of Arsenic.
762. The exact determination of the quantity of arsenic
present in a mixture containing much organic matter is
attended with great difficulty. In general, a sufficiently
accurate estimate of the amount may be found by comparing the crusts obtained by Marsh's test with those
furnished by known quantities of arsenious acid, but
should a direct determination be necessary, it may be
effected by a process of which an outline is here given,
though without the minute details of manipulation requisite for perfect accuracy.




QUANTITATIVE DETERMINATION OF ARSENIC. 291
After having obtained the arsenic in a state of solution
by heating the organic matter with hydrochloric acid and
chlorate of potash, as described above, the clear liquid
is mixed, in a flask, with a strong solution of bisulphite
of soda until it smells very strongly of sulphurous acid,
even after being heated for some minutes in a water-bath
to reduce the arsenic acid (AsO,) to the state of arsenious
acid (AsO3). The application of heat is continued till
the smell of sulphurous acid has disappeared, and the
solution is thoroughly saturated with sulphuretted hydrogen, after which the flask is corked and set aside in
a warm place for some hours. The precipitate, containing
sulphide of arsenic mixed with organic matter, is collected upon a filter, washed, and dried. The dry precipitate is mixed with about six parts of nitre and six parts
of dry carbonate of soda, and projected, by degrees, together with the fragments of the filter, into a red-hot por
celain crucible. The deflagrated mass, containing arseniate of potash, is dissolved in a little water, the solution
filtered if necessary, and mixed with chloride of ammo
nium, ammonia,o and sulphate of magnesia.  After being
well stirred, it is set aside for twenty-four hours, when
the arseniate of magnesia and ammonia will have separated as a crystalline precipitate, which must be collected
on a weighed filter, washed with dilute ammonia, dried
at 2120 and weighed (753a). The quantity of arsenious
acid is calculated by the proportion,
2MgO,NH40,AsO5s HO. AsOs.
190: 99:: Weight of the precipitate: x.
* Should any precipitate be caused by the ammonia, it must be
filtered off.




292   ELECTROLYTIC TEST FOR ANTIMONY.
CHAPTER II.
ANTIMONY.
763. THE form in which antimony is generally met
with in medico-legal investigations, is the double tartrate
of antimony and potash (KO,SbO3,C8Hd40,0+Aq), commonly called tartar-emetic or tartarized antimony, which
is often taken medicinally, and occasionally as a poison.
It may be recognized by applying to its solution the following tests.
(a) Hydrochloric acid, which gives a white precipitate
of teroxide of antimony (SbO3) soluble in excess.
(b) Hydrosulphuric acid, in the solution form (a), gives
a bright orange precipitate.
(c) Hydrochloric acid and metallic copper (749), on the
application of heat, will give a purplish black deposit of
metallic antimony, upon the surface of the copper. The
latter, when dried and heated in a tube, will not yield a
crystalline sublimate like arsenic, but may give a white
amorphous deposit on strongly heating. The deposit is
dissolved by boiling the strip of copper in a dilute solution of potash, and if the solution be treated with sulphuretted hydrogen, filtered from any precipitate, and
acidulated with hydrochloric acid, the orange sulphide
of antimony is precipitated.
(d) Marsh's test (745) will yield metallic crusts of antimony, as with arsenic, but the antimonial crusts are
readily distinguished by the following characters. (1)
They are much less volatile than those of arsenic, and
are therefore deposited very much nearer to the heated
portion of the tube. (2) They give no crystalline sublimate when heated in a tube, but, with a strong heat, an
amorphous sublimate. (3) Antimonial crusts will not
dissolve easily in solution of chloride of lime; but (4)




ANTIMONY IN ORGANIC MATTER.             293
they do so at once in yellow sulphide of ammonium, and
if the solution be slowly evaporated, it leaves an orange
residue of sulphide of antimony (SbS3). (5) When oxidized by nitric acid and evaporated, the antimonial crust
gives a residue which refuses to dissolve in water and
produces a dirty gray precipitate with nitrate of silver
(compare 748 a, b, c).
(e) The electrolytic test evolves antimonietted hydrogen far less readily than arsenietted hydrogen, most of
the antimony being deposited as a black coating upon
the platinum plate connected with the zinc end of the
battery. If the plate be washed, and gently heated with
a little yellow sulphide of ammonium, it dissolves the antimony and leaves the orange residue when evaporated.
By pouring a strong solution of hydrosulphuric acid
down the funnel-tube at the commencement of the electrolysis, it will entirely prevent the evolution of antimonietted hydrogen, whilst it promotes that of arsenietted
hydrogen.
(f) If a solution of antimony, acidified with hydrochloric acid be poured into a platinum capsule, or placed
upon platinum foil (or even upon a gold or silver coin),
and a strip of zinc (or iron, such as a knife blade) be
placed in it, a black deposit of antimony will be found
around the point of contact of the two metals. The deposit may be tested by placing a drop of yellow sulphide
of ammonium upon it, and evaporating to obtain the
orange residue, which should be compared with the residue left by a drop of sulphide of ammonium  alone upon
the uncoated metallic surface.*
SECTION I.
Detection of Antimony in the presence of Organic Matter.
764. For the detection of antimony in organic liquids
and solids, the same methods of proceeding are adopted
as in the case of arsenic (751-761), the antimony being
recognized by the characters described in 763.
765. Should both metals be present, they may still be
Of course a surface of silver would be blackened by the sulphide,
25*




294                  MERCURY.
easily detected, unless there was a very great disproportion between them, by the behavior of the crusts obtained
in Marsh's test.
766. Even if one of the metals largely predominates,
the electrolytic test permits the detection of both; it is
only necessary to allow the electrolysis to proceed for
five or ten minutes in order to deposit the antimony on
the negative plate before adding the hydrosulphuric acid,
which will at once arrest the evolution of the antimonietted hydrogen, and if the reduction tube be changed, a
deposit of pure arsenic or sulphide of arsenic will be
obtained.
SECTION II,.
Quantitative Determination of Antimony.
767. The remarks in paragraph 762, upon the determination of the quantity of arsenic will apply also in
the case of antimony, and precisely the same steps must
be taken in order to ascertain the amount of the latter
metal, except that dried nitrate of soda should be used
instead of nitrate of potash for the deflagration of the
sulphide. On digesting the fused mass in the cold, with
a little water, almost the whole of the antimony will be
left in the form of antimoniate of soda (NaO,SbOW), which
must be collected upon a filter, washed with cold water,
dried, and fused with five or six times its weight of cyanide of potassium in a porcelain crucible, until the antimony has collected into a globule at the bottom of the
fused mass. The latter is dissolved, when cold, in water,
and the metallic button weighed. Each grain of antimony
corresponds to 2'73 grains of crystallized tartar-emetic.
CHAPTER III.
MERCURY.
768. THE most common preparation of mercury, by
which life has been sacrificed or endangered, is the




MERCURY IN- ORGANIC MIXTURES.    295
chloride (HgCl), commonly called corrosive sublimate;
the subehloride, or calomel (Hg2C1), the red oxide (HgO),
and some of the other compounds, are also sometimes
administered, either criminally or accidentally, with fatal
effect, and may consequently have to be looked for by
the medical jurist. In the process I am about to describe,
however, any of these compounds will be brought into a
state of solution; after which the mercury contained in
them may readily be detected by the proper tests.
SECTION I.
Detection of Mercury in Organic Mixtures.
769. When the presence of mercury is suspected in an
organic mixture, such as the contents of a stomach, the
solid and liquid portions of the matter to be examined
may be separated from each other, either by filtration or
decantation, provided the separation takes place readily;
or if this is not the case, the whole of the mixture may
be treated with acid, and examined in the manner described in paragraphs 774-776.
770. Examination of the ligquid portion.-The liquid
portion may be first examined. Acidify it with a few
drops of hydrochloric acid, and boil the mixture for a
quarter or half an hour, with two or three strips of clean
copper foil. If any mercury is present in the liquid, it
will in this way be entirely separated from the solution
and deposited on the surface of the copper. The latter
is then removed from the acid liquid, and washed with
a little dilute solution of ammonia, in order to remove
from the surface any adhering oxide or subsalt of copper.
The strips are then dried by gentle pressure between
folds of bibulous paper, and placed in a small and perfectly
dry German glass tube, three or four inches long, closed
at one end.
771. The heat of a spirit lamp is then applied to the
bottom of the tube containing the copper strips; when,
if any mercury has been deposited upon them, it will be
volatilized by the heat, and condensed in the cooler part of
the tube, forming a delicate and dew-like ring of minute
globules of metallic mercury; the real nature of which may




296    MERCURY IN ORGANIC MIXTURES.
be at once seen with the assistance of a common lens, if not
with the naked eye.
771a. If the sublimate is so minute that the globules
are not distinguishable, it may be gently rubbed with a
glass rod to unite the small globules. The strip of copper
may be shaken out of the tube, a very minute particle
of iodine introduced, and a gentle heat applied to vaporize
it. The mercurial sublimate will thus be converted into
iodide of mercury, which is yellow at first, and becomes
scarlet when rubbed with a glass rod (Lassaigne).
772. If, in the experiment above described (771), the
appearance of metallic globules is distinctly visible, it
will scarcely be necessary to apply any further tests to
prove the presence of mercury, since no other substance
is capable of producing such a sublimate. If, however,
any doubt exists as to the nature of the sublimate, the
following experiments may be made:773. Remove the copper from the tube, and dissolve the
sublimate in nitrohydrochloric acid; by which the mercury, if present, will be converted into the soluble chloride
(HgCl). Expel the excess of acid by evaporation at a
gentle heat; and apply to an aqueous solution of the
residue, the following tests:(a) Solution of iodide of potassium (KI) gives abrilliant
red precipitate of iodide of mercury (igl), which is very
soluble in excess of the iodide of potassium.
(b) Solution of potash gives a yellow precipitate of
hydrated oxide of mercury, which is insoluble in an
excess of the precipitant.
(c) A solution of hydrosulphuric acid (sulphuretted
hydrogen), or a drop or two of hydrosulphate of ammonia, forms at first a white precipitate, consisting of a
double compound of chloride and sulphide (2HgS,HgCl),
which, unless the precipitant be added very sparingly,
almost immediately becomes darker, owing to the admixture of the black sulphide (HgS). If the precipitant be
added in excess, the whole of the precipitate becomes
black.
(d) The dry mercurial salts, when mixed with carbonate of soda, and-heated in a narrow tube before the




ELECTROLYTIC TEST FOR MERCURY.   297
blowpipe, yields a sublimate of minute globules of
metallic mercury.
774. Examnination of the solidportion.-The solid portion
of the mixture may contain mercury in combination
with certain animal matters, besides particles of calomel,
oxide, or some other mercurial compound. It may first
be examined for any visible fragments of these, which, if
detected, may be picked out, and tested for mercury, by
mixing them, when dry, with carbonate of soda, and
heating the mixture in a small tube before the blowpipe;
when the mercury will be sublimed into the cooler part
of the tube (773 d).
775. The rest of the solid matter may now be warmed
with a little hydrochloric acid and chlorate of potash, as
directed in 761; one part of the filtered solution may be
tested by boiling with copper, and the other may be
subjected to electrolysis according to the directions given
in 753.
If mercury be present in the solution, it will be deposited upon the negative plate (connected with the zinc
end of the battery), and may be readily detected by
boiling the plate in a few drops of nitric acid, expelling
the greater excess of the latter by evaporation, rendering
the solution alkaline with ammonia (because the free
nitric acid would dissolve the copper), acidifying very
slightly with hydrochloric acid, and boiling with a slip
of clean copper foil, which may afterwards be washed
and heated in a tube. If the negative plate be of gold
(or of platinum gilt by immersing it whilst attached to
the battery, in a solution of cyanide of gold in cyanide
of potassium), the mercury will of course be easily recognized by the silvery appearance of the deposit.
In the absence of a galvanic battery, the solution
obtained by means of hydrochloric acid and chlorate of
potash may be mixed with excess of hydrosulphuric acid
and heated for some time, when the black sulphide of
mercury will be deposited, and may be collected on a
filter and washed; it will be found nearly insoluble in
hot nitric acid, but readily soluble in a mixture of nitric
and hydrochloric acids. The presence of mercury in the
solution may be proved by evaporating it to a small bulk,




298                    LEAD.
adding ammonia in excess, then hydrochloric acid in
excess, and boiling with metallic copper (770).
776. A very small quantity of mercury may also be
detected by placing the solution upon a gold or copper
coin, and touching the gold, through the liquid, with a
piece of zinc or the blade of a knife, when a silvery
deposit will be formed around the point of contact, and
will disappear when the washed coin is gently heated.
SECTION II.
Detection of Mercury in the Tissues.
777. When the presence of mercury is suspected in
the viscera or other tissues of the body, the part intended
for examination should first be cut into thin slices, and
heated with hydrochloric acid and chlorate of potash
(761); by which means any mercury that may be present
will be converted into the bichloride, and thus brought
into a state of solution. The undissolved matter is then
separated by filtration or decantation, and the liquid
portion evaporated to a small bulk on a water-bath, and
treated as in 775.
CHAPTER IV.
LEAD.
778. ALTHOUGH instances of criminal poisoning with
compounds of lead are of comparatively rare occurrence,
still the accidental admission of it into the system, either
in the form of the solid carbonate (white lead) so extensively employed in the arts, or through the medium of
water impregnated with it, very frequently leads to
serious and even fatal results; so that its detection is
often a matter of grave importance.
779. In testing for minute quantities of leadit must
be borne in mind that several of the test solutions
employed in analysis, when kept even for a few weeks




WATER IMPREGNATED WITH LEAD.    299
in bottles of flint glass, dissolve out very perceptible
traces of the metal from  the glass, in which it is present
in considerable quantity; so that, unless the experimenter
is on his guard, he may be led to suppose that he has
detected the metal in the liquid which he is examining,
while, in fact, he has himself introduced it in one of his
reagents. Solutions of potash and soda, and their carbonates, are especially liable to become in this way
impregnated with lead; and several other saline solutions
also, under peculiar circumstances, do the same, though
more slowly, and in a less degree. On this account it
is always advisable to test each of the reagents employed
with solution of hydrosulphuric acid in large excess,
which will, if any traces of lead are present, give the
liquid a more or less decided brown tint; or even cause
a black precipitate, if the quantity of metal is at all
considerable.
SECTION I.
Examination of WlTater suspected to be impregnated with Lead.
780. The water intended for examination (which should
always be tested as soon as possible after being taken
from the cistern or pipe in which it has been standing)
is placed in a beaker or bottle of German or green glass,
free from lead, the surface of which should be washed
perfectly clean with distilled water. A stream of hydrosulphuric acid (sulphuretted hydrogen) gas is then transmitted through the water, until the latter smells distinctly
of the gas. When lead is present, the liquid will generally assume a brown tint almost immediately, unless
the quantity of lead is extremely small; but before deciding that the water is pure, it should be set aside for a
few hours, after being saturated with the gas, during which
time the sulphur will be partially precipitated, owing to
the decomposition of the hydrosulphuric acid by the
oxygen  of the air, mixed, if any trace of lead  is
present, with a little sulphide (PbS), which will give the
sediment a more or less decided brown or fawn color.
If, on the contrary, the water continues colorless, and
the precipitated sulphur is white, or of a very pale




300          DETECTION OF LEAD IN
sulphur color, it may be concluded that no perceptible
trace of lead is contained in the water.
781. The most satisfactory method of applying this
test for lead in waters is the following. Two test-tubes
of clear white glass, free from lead, about nine inches
long, and half an inch in diameter, are nearly filled, one
with pure distilled water, the other with the water under
examination, to which a few drops of pure acetic acid
are added to prevent the precipitation of any sulphide of
iron. A  similar quantity of acetic acid having been
added to the distilled water, for the purpose of comparison, the contents of both tubes are tested either with a
clear solution of hydrosulphuric acid, or with a few
bubbles of the gas. By holding both tubes, after shaking
over a sheet of white paper, so that the eye may look
along the axis of each tube, the slightest trace of lead
may be discovered by the dark color of the liquid, and
all fallacy is excluded by the comparison with the pure
water. It is evident that by comparing the result with
those furnished by solutions containing known quantities
of lead, a close approximation to the amount of the latter
may be arrived at.
782. Lead may also be detected in waters by evaporating a quart to dryness, heating the residue with strong
hydrochloric acid, and mixing the hydrochloric solution
with a large excess of strong solution of hydrosulphuric
acid, when the purplish black precipitate, or color, of
sulphide of lead will be obtained.
SECTION II.
Detection of Lead in Organic lixtures.
783. If the organic matter to be examined is a mixture of solid and liquid, such as the contents of a stomach,
the two portions should, if practicable, be separated by
filtration through paper or muslin; having been previously diluted, if necessary, with a little water, and gently
heated with a drachm or two of pure acetic acid, which,
will cause the liquid to pass more readily through the
pores of the filter. The liquid portion may be first
tested; and in case none of the metal can be detected in




ORGANIC MIXTURES.                 301
it the solid or semi-solid matter may be afterwards examined (788).
784. Examination of the liquid portion.-A current of
hydrosulphuric acid gas is passed through the liquid for
about a quarter of an hour, by which means any lead
that may be dissolved will be precipitated as the black
sulphide.* This is to be separated by filtration, and the
greater part of it digested, with the aid of a gentle heat,
in moderately dilute nitric acid; a small portion being
retained for examination with the blowpipe (787).
785. When the sulphide is for the most part decomposed by the nitric acid (which may be known by the
undissolved residue, consisting chiefly of sulphur, becoming nearly white), the clear solution is to be filtered
from the insoluble matter, and tested in the following
manner (786); the undissolved residue being also retained,
in case it may be required for subsequent examination
(787). The digestion in warm acid should not be continued longer than necessary, since the prolonged action
of the nitric acid might have the effect of oxidizing the
sulphur as well as the lead, forming sulphuric acid, which
would combine with the oxide of lead, and precipitate it
from the solution in the form of the insoluble sulphate
(PbO,SO3).
786. The clear solution (785) is now to be evaporated
to dryness on a water-bath, in order to expel the excess
of nitric acid; after which the residue is to be redissolved
in warm water, and tested in the following manner; or,
if the quantity is small, the tests b, c, and d only need be
applied.
(a) Hydrosulphuric acid and hydrosulphate of ammonia
cause a black precipitate of sulphide of lead (PbS).
(b) Dilute sulphuric acid, or a solution of sulphate of
soda, gives a white precipitate of sulphate of lead (PbO,
SO3), which is insoluble, or nearly so, in acids, but gradually dissolves in a solution of caustic potash.
(c) The sulphate formed in b, after being washed with
* Minute quantities of lead escape precipitation in liquids containing organic matter, and can only be detected by evaporating to dryness and incinerating the residue (788).
26




302  DETECTION OF LEAD IN ORGANIC MIXTURES.
distilled water is instantly blackened when moistened
with hydrosulphate of ammonia or a solution of hydrosulphuric acid, owing to the formation of the black sulphide. The sulphate of lead may in this way be readily
distinguished from the sulphates of baryta and strontia,
which it resembles in many respects.
(d) A solution — 6f iodide of potassium (KI) throws
down a bright yellow precipitate of iodide of lead (PbI),
which is soluble in hot water, and, on cooling, separates
from the solution in the form of brilliant crystalline
scales of great beauty.
(e) Hydrochloric acid or a solution of chloride of
sodium, causes, if the solution is not very dilute, a white
crystalline precipitate of chloride of lead (PbCl), which
dissolves when the mixture is heated, and crystallizes in
the form of delicate needles as the solution cools.
(f) Chromate of potash (KO, Cr,03) gives a rich yellow
precipitate of chromate of lead (PbO,CrO3), which is
soluble in potash, and insoluble in dilute acids.
(g) If any of the precipitates formed in the above
experiments be dried, and heated on charcoal, with or
without a little dried carbonate of soda, in the inner
flame of the blowpipe, minute metallic beads will be
obtained; which may be recognized as lead by their
softness and malleability; a yellow incrustation of oxide
of lead appears upon the charcoal.
787. If no decided indication of lead can be obtained
from the nitric acid solution, the other portion of sulphide
(784), and also the residue which proved insoluble in the
acid (785), may be dried, mixed with carbonate of soda,
and heated in the inner flame of the blowpipe; when, if
any lead- is present, it will be speedily reduced to the
metallic state, forming minute malleable beads.
788. Examnination of the solid portion.-If the examination of the liquid portion should fail in proving the
presence of lead, the poison may still be sought for in
the solid or semi-solid matters left on the filter (783)
since it may exist in combination with animal matter, or
in some other insoluble form. The mixture is evaporated
to dryness, and the dry mass incinerated in a clean fireclay or porcelain crucible. The gray ash is reduced to




DETECTION OF LEAD IN THE TISSUES.  303
powder and treated with boiling water as long as a drop
of the washings leaves any residue when evaporated on a
slip of glass. The solution thus obtained may possibly
contain lead, and should therefore be tested with sulphuretted hydrogen (784).
789. But the greater part of the metal would remain
in the residue, which must now be boiled with a mixture
of equal measures of nitric acid and water for a few
minutes. The filtered solution is examined for lead as
in 786.
790. The residue left undissolved by nitric acid may
still contain lead in the form of sulphate: by boiling it
with a little acetate of ammonia (prepared by mixing
ammonia with acetic acid in slight excess), this may be
extracted, and the lead detected in the solution by hydrosulphuric acid. It may still be advisable to dry the
residue, mix it with carbonate of soda and charcoal, and
fuse it at a bright red heat, either before the blowpipe,
or in a covered crucible, in order to obtain if possible a
bead of metallic lead.
SECTION III.
Detection of Lead in the Tissues.
791. When, in a suspected case of poisoning by lead,
no trace of the metal can be detected in the contents of
the stomach, &c., it is necessary, before deciding upon
the absence of the poison, to examine the tissues of the
stomach, intestines, and especially the liver; since it may
be often found absorbed in these tissues, even when no
trace is to be met with elsewhere.
792. The portion of the body intended for examination
is to be cut into thin slices, dried, incinerated as completely as possible at a moderate heat, and examined as
in 788-790.




304         DETECTION  OF COPPER IN
CHAPTER V.
COPPER.
793. LIKE lead, copper is not often employed for the
purpose of criminally destroying life; but is not unfrequently taken accidentally dissolved in articles of
food, with serious, and sometimes fatal results.  The
chief cause of such accidents is the employment of
untinned copper vessels for culinary purposes; and
although such vessels, when perfectly clean, may be used
in the preparation of certain articles of food without
risk of impregnation, still the number of alimentary
substances capable of acting upon and dissolving small
quantities of the metal, is so great, that it is far safer to
avoid the use of untinned copper vessels in all culinary
operations. Acid and fatty substances especially, and
liquids containing common salt and other saline matters
in solution, should never be boiled in such vessels; since
the quantity of copper dissolved by them is sometimes
so considerable as to impart a green or.bluish color to
the mixture.
SECTION I.
Detection of Copper in Organic Mixtures.
794. Copper may exist in such mixtures either in a
state of solution, or in combination with certain organic
or other substances, forming compounds which are more
or less insoluble in water. On this account, when the
mixture to be examined consists of both liquid and solid
matters, it should first be warmed with a little hydrochloric or acetic acid, by which means the copper will be
brought into solution. The solution may then be filtered
from the insoluble portion, which latter should be retained,
in case it may be required for subsequent examination.
795. The clear liquid, slightly acidified with a few




ORGANIC MIXTURES.                305
drops of hydrochloric acid, is now to be tested for copper,
by placing in it a piece of clean iron, free from rust, such
as a needle or knife blade. If copper is present in the
liquid, it will in a short time be deposited in the metallie state on the surface of the iron, giving it all the appearance of copper; while the iron is at the same time
dissolved in atomic proportion. The color of the freshly
deposited copper is so peculiar and characteristic, that it
can hardly be mistaken after being once seen; so that
this experiment is generally sufficient of itself to prove
the presence of the metal. If, however, any doubt exists
as to its presence, the following tests may be applied,
either to a portion of the liquid from which the copper
has not been removed by means of the iron, or to a solution of the precipitated copper, scraped off the iron, in
dilute nitric acid.
796. (a) Hydrosulphuric acid and hydrosulphate of
ammonia throw down a black precipitate of sulphide of
copper (CuS).
(b) Ammonia, when added in small quantity, throws
down a pale blue precipitate, which, if the ammonia be
added in excess, redissolves, forming a beautiful blue solution.
(c) Potash throws down in the cold solution a pale blue
precipitate of hydrated oxide (CuO,IO); which, on boiling the mixture, becomes black, owing to the formation
of the anhydrous oxide (CuO). The potash must here be
added slightly in excess, as otherwise the precipitate
would consist of a basic salt, which would not become
black when boiled.
(d) Ferrocyanide of potassium causes, even in very
dilute acid or neutral solutions, a mahogany-colored precipitate of ferrocyanide of copper (Cu2,FeCy3), which is
insoluble in dilute acids.
797. In case no copper can be detected in the liquid
portion, it is advisable, before deciding that the metal is
altogether absent, to examine the residue which proved
insoluble in the dilute acid- (794). For this purpose it is to
be evaporated to dryness, and ignited in a covered Berlin porcelain crucible. The incinerated residue is then
warmed with a little dilute nitric acid, which will dissolve
26*




306 DETECTION OF COPPER IN THE TISSUES.
any traces of copper that may be present. The acid solution is evaporated nearly to dryness, in order to expel most
of the excess of acid, and filtered; after which the solution may be tested with a piece of clean iron (795), and
also, if necessary, with the other reagents above enumerated (796).
798. When the solution containing copper, even in the
presence of much organic matter, is subjected to electrolysis (753), the metal is deposited upon the negative plate,
and may be recognized by its color, and by the appropriate tests (796) applied to the solution obtained by
boiling the negative plate with nitric acid.
SECTION II.
Detection of Copper in the Tissues.
799. Like the other metallic poisons, copper is readily
absorbed by the tissues, where it may frequently be
found in cases where no trace can be detected in the contents of the stomach and intestines. On this account, it
is necessary, before concluding that no copper can be
found, to examine the liver and other viscera, which may
be done in the following manner.
800. The part intended for examination is to be cut
into thin slices, and treated with hydrochloric acid and
chlorate of potash, as directed in 761. The acid solution,
after filtering, is evaporated nearly to dryness; after
which it may be tested with a piece of clean iron (795),
and, if necessary, by paragraphs 796, 798.
If no copper can be detected in this solution, the insoluble organic matter may be incinerated and examined
according to 797.
SECTION III.
Quantitative Determination of Copper.
801. The quantity of copper present in any organic
mixture may be ascertained by incinerating the dried
organic matter, boiling the ash with dilute nitric acid,
saturating the liquid (after filtering) with hydrosulphuric
acid gas, which will throw down the whole of the copper




ZINC.                        307
as sulphide. The precipitate is to be dissolved in hot
nitric acid, and the copper thrown down as oxide, by
supersaturating the hot solution of the nitrate with potash.
The black oxide thus precipitated is to be washed with
a large quantity of hot water, filtered, dried, ignited, and
weighed.  From  the weight of the oxide, that of the
metallic copper may be calculated as follows:Ate. wt. of oxide   Ate. wt. of    Wt. of oxide  Wt. of copper in the quantity
of copper.   copper.     obtained.    of mixture employed.
40           32::    a                  x
CHAPTER VI.
ZINC.
Detection of Zinc in Organic Mixtures and in the Tissues.
802. ZINC has occasionally to be looked for in organic
mixtures and in the tissues, the sulphate being often administered as an antidote in cases of poisoning. It may
be detected by boiling the suspected matters, in a finely
divided state, with a little dilute hydrochloric acid and
chlorate of potash, and filtering, if necessary, from any
insoluble residue. The clear solution thus obtained may
then be supersaturated with ammonia, and filtered, after
which the clear ammoniacal solution may be tested with
a current of hydrosulphuric acid gas (sulphuretted hydrogen), which, if zinc is present, will throw down a
white precipitate of sulphide (ZnS).  The sulphide thus,;
formed may be separated from the liquid by filtration,
and dissolved in a little nitric acid; the excess of acid
employed being afterwards expelled by evaporating the
solution to dryness.*
803. The residue should be boiled with water and a
* If this residue is carbonized when further heated, it is advisable
to continue the heat as long as any vapors are evolved, to boil the
charred mass with hydrochloric acid, and to evaporate the filtered
liquid to dryness.




808                       ZINC.
little nitric acid, the solution filtered, if necessary, and
examined by the following tests:(a) Add ammonia in excess; filter the solution from
any precipitate which may be formed, and add hydrosulphate of ammonia: if zinc be present, a white flaky precipitate of sulphide of zinc should be produced.*
(b) Add ammonia in excess; filter, if necessary, acidify
the filtered liquid with acetic acid, and add ferrocyanide
of potassium; a white precipitate of ferrocyanide of zinc
should be obtained.
(c) Mix the remainder of the solution with carbonate
of soda in slight excess, and boil for a few minutes;
collect the precipitate (basic carbonate of zinc) upon a
filter, wash it, and incinerate the filter when dry, in a
small porcelain crucible. If zinc be present, the ash
will be yellow while hot, and white on cooling. Place it
in a small cavity on a piece of charcoal, moisten it with
nitrate of cobalt, and heat strongly before the blowpipe;
a green mass should be produced if zinc be present.
804. If it be desired to examine the zinc in the residue
left by the hydrochloric acid and chlorate of potash (802),
it must be washed, dried and calcined at a low red heat
in an open crucible. The mass may then be boiled with
hydrochloric acid, the filtered solution evaporated to
dryness and further tested as directed above (803).
* If ammonia had not previously been added in excess, the hydrosulphate of ammonia would have given a white precipitate of sulphur,
even if no zinc were present; but this precipitate would simply irnpart a milky appearance to the liquid instead of separating in distinct
flakes. The precipitate of sulphate of zinc is usually dirty white,
from the presence of a little sulphide of iron.




IODINE.                     309
CHAPTER VII.
IODINE.
SECTION I.
Detection of Uncombined Iodine in Organic Mixtures, &c.
805. WHEN iodine is present in an organic mixture, it
may be detected in the following manner, which will also
serve to identify it after having been absorbed by the
tissues of the stomach, liver, or other organ, such organ
having been firstcarefully cutout into thin slices, and macerated with a little water. The characteristic smell of
iodine is generally perceptible in liquids containing it;
and it usually imparts to organic mixtures a yellow or
greenish color.
806. The mixture may first be examined for any particles of iodine that may be present in the solid state;
which, if found, may be at once identified as such by the
beautiful violet-colored vapor which they form when
gently heated in a small glass tube.*
807. If no solid iodine can be found, the liquid may
be tested with a solution of starch; or a strip of cotton
or paper, impregnated with starch, may be moistened
with it. If iodine is present in the solution, it will immediately strike a more or less decided purple color, the
intensity of the tint varying from almost black to a pale
shade of pink or lilac, according to the quantity of iodine
dissolved in the liquid.
808. Should the quantity of iodine in the solution be
so minute as to fail in producing a sufficiently decided
* Since indigo also gives violet vapors, the next test should always
be applied.




310                     IOZDINE.
result, the liquid may be well shaken with a little chloroform, which will dissolve the iodine and acquire a
beautiful violet color.  The mixture is allowed to stand
in order that the chloroform may collect at the bottom
of the vessel, and the aqueous liquid is drawn off by a
syphon or pipette.  The chloroform  is poured into a
watch-glass, and allowed to evaporate spontaneously,
when the iodine will be left, and may be recognized
either by heating it in a tube (806) or by stirring it with
water and adding a little thin starch paste (807).
809. If the iodine be present in the solution as an
iodide, it must be liberated previously to the application
of the above tests. For this purpose the organic mixture
should be slightly acidulated with hydrochloric acid,
heated for some time upon a water-bath, and, if necessary,
filtered. The cold solution is then mixed with a little
sesquichloride of iron, to which enough dilute sulphuric
acid has been added to render it colorless, and agitated
with chloroform, when the liberated iodine will be recognized as in 808. In this process the persalt of iron is
reduced to the condition of a protosalt, by imparting an
atom of oxyvgen to the hydrogen or metal in combination
with the iodine, which is thus set free:Iodide   Persulphate    Sulphate  Protosulphate
potassium.   iron.    potash.      iron.
KI +  Fe2O3,3SO3 =  KO,SO3 + 2(FeO,SO3) + I.
Chlorine and chloride of lime are sometimes employed
to liberate the iodine, but it is not easy to avoid the
addition of an excess which converts the iodine into
chloride of iodine.*
* The introduction of a little sulphuric acid and a piece of zinc,
however, will restore the blue color when destroyed by an excess of
chlorine.




SULPHURIC ACID.                 311
(CHAPTER VIII.
SULPHURIC ACID (HO,S03).
SECTION I.
Detection of Sulphuric Acid in Organic Mixtures.
810. SULPHURIC acid may be readily detected, even
when mixed with a large quantity of foreign matter.
Should the substance to be examined be viecid or semii
solid, it may be diluted with a little water, and boiled;
after which, if any solid matter remains in suspension, it
may be filtered through muslin or paper.
811. If the liquid contains free sulphuric acid, it will of
course strongly redden blue litmus paper.
812. Mix the liquid to be tested with a little hydrochloric acid, and add a solution of chloride of barium or
nitrate of baryta. If sulphuric acid is present, a copious
white precipitate of sulphate of baryta will be produced,
which will not dissolve on boiling the acidified mixture,
nor yet on diluting it with a considerable quantity of
water.
813, Since traces of sulphuric acid may be contained
in the nitric acid used in acidifying the mixture (814), a
little of the nitric acid employed should be diluted with
three or four times its bulk of water, and tested with
chloride of barium.
814. It is possible, also, that the substance under examination may contain some soluble sulphates in solution, as sulphate of magnesia, sulphate of zinc, &c., which
would cause the precipitation of sulphate baryta with
chloride of barium, even when no free sulphuric acid is
present. To remove this source of error, a little of the
suspected fluid may be evaporated nearly to dryness at a




312   DETECTION OF SULPHATE OF INDIGO.
gentle heat, when any saline matter that may be present
will crystallize out; while the free sulphuric acid will
continue liquid, and may be identified by the proper
tests.
815. It is not often, however, that any serious uncertainty can exist as to whether the sulphuric acid found
mixed with organic matter was or was not uncombined,
especially in cases of suspected poisoning; since the
corrosive effects of the acid upon the parts with which it
has been in contact, or other corroborative circumstances,
will generally of themselves furnish evidence sufficiently
conclusive.
816. A very simple and delicate test for free sulphuric
acid consists in dipping a piece of white linen or paper
into the solution, and drying it before the fire. As the
water evaporates, the acid will carbonize the fabric. Solutions containing organic matter as well as free sulphuric
acid yield a carbonaceous mass when evaporated nearly
to dryness.
SECTION II.
Detection of Sulphuric Acid in Stains on Clothing.
817. The stains formed by sulphuric acid on articles
of clothing are usually moist to the touch, and most
commonly of a brown or red color, varying, however,
with the nature of the material and of the dye. The
acid may be detected in them by boiling the stained part
with water, and testing the solution as in the preceding
section.*
SECTION III.
Detection of Sulphate of Indigo in Organic Mixtures, &c.
818. The solution of indigo in sulphuric acid, commonly called sulphate of indigo, which is occasionally
either employed as a poison, or criminally thrown upon
the person, may be detected in the same manner as the
simple acid. It has a deep blue color, which may be
destroyed by boiling with nitric acid previous to the
* When the stained fabric is dried before the fire, it becomes charred
where the acid had touched it.




HYDROCHLORIC ACID.                313
application of the tests; after which the sulphuric acid
may be identified either in organic mixtures or on articles
of clothing, by the experiments described in paragraphs
812 —817.
CHAPTER IX.
HYDROCHLORIC ACID (HC1I).
SECTION I.
Detection of Hydrochloric Acid in Organic Mixtures.
819. WHEN free hydrochloric- acid is present in an
organic mixture, it may be detected in the following
manner. If solid or semi-solid matter is mixed with the
liquid it should be first boiled, and filtered through
muslin; and when the mixture is thick and viscid, a little
water should be mixed with it before boiling. The
liquid is then treated with a tolerably strong infusion of
galls, as long as it causes a precipitate, in order to throw
down most of the dissolved animal matter, which would
otherwise tend to prevent the acid distilling over. The
precipitate is then separated from the clear liquid, either
by again filtering through muslin, or by decantation.
820. A few drops of the solution, thus purified from
the greater portion of the organic matter, may now be
tested with nitrate of silver. If this causes a white precipitate, soluble in ammonia, and insoluble in nitric acid,
the liquid will have to be further examined (821); since
the precipitate may be owing to the presence of chloride
of sodium or some other soluble chloride. But if no
such precipitate is occasioned by the silver salt, the
absence of hydrochloric acid may be relied on; unless,
indeed, the solution is amrnmoniacal, in which case it should
first be neutralized or slightly supersaturated with nitric
acid.
821. In order to prove whether the precipitate caused
27




314   DETECTION  OF HYDROCHLORIC ACID.
by nitrate of silver is owing to the presence of free hydrochloric acid, or of some soluble chloride, the liquid is
to be distilled to dryness in a retort. The neck of the
retort is to be attached by means of a perforated cork to
a quilled receiver, the quill of which should be allowed
to dip just below the surface of a little pure water placed
in the flask or bottle intended for its reception. The bulb
of the retort is to be heated in a chloride-of-calcium bath;
the heat of which may be raised, towards the end of the
distillation, to about 230~.
822. When the whole of the liquid has distilled over,
the contents of the receiver are to be examined, first with
blue litmus paper, which, if any free acid is present, will
become reddened; and also with nitrate of silver, which
will give a copious white precipitate of chloride, soluble
in ammonia, and insoluble in hot nitric acid, in case any
free hydrochloric acid was present in the mixture, since
such acid would distil over with the water.
823. A little of the distilled liquid may also be mixed
with a few drops of pure nitric acid, and boiled for a few
minutes with a small fragment of gold leaf. If the latter
dissolves, it is an additional proof that the acid is hydrochloric.
824. In examining the contents of a stomach, it must
be borne in mind that minute quantities of free hydrochloric acid are probably always present as one of the
normal constituents of the gastric juice; so that the distilled liquid may always be expected to contain some
traces of it.  The amount of the acid derived from this
source is, however, so small, that it may readily be distinguished from the comparatively large quantity usually
to be found when the acid has been swallowed.*
SECTION II.
Quantitative Determination of Hydrochloric Acid.
825. The chloride of silver (AgCl) obtained by adding
nitrate of silver to the distilled acid liquid (822), is to be
* It must be remembered that free hydrochloric acid would distil
over from mixtures containing chlorides together with free sulphuric,
phosphoric, oxalic, or lactic acid.




NITRIC ACID.                    315
washed on a filter, dried and heated to dull redness in a
counterpoised porcelain crucible, until it begins to fuse.
From the weight of the chloride thus obtained, that of the
hydrochloric acid present in the mixture may be calculated as follows:Ate weighe t   Ate. wt. of hydro-  Wt. of chloride Wt. of hydrochloric acid
of chloride  chloric acid.  obtained.   in the quantity of
of silver.                             mixture employed.
143'5:    36-5::    a:        x
CHAPTER X.
NITRIC ACID (HO, NO5).
SECTION I.
Detection of Nitric Acid in Organic Mixtures.
826. IF any solid or semi-solid organic matter is
present in the mixture, it should be separated by filtering through muslin, having first heated it on a waterbath in order to effect a separation of the greater part of
the acid present, from the solid matters which may be
more or less impregnated with it. Should the liquid be
thick and viscid, it may be first diluted with a little water.
827. If free nitric acid is present in any considerable
quantity in the liquid, it will probably be recognized by
its peculiar smell; and the characteristic yellow stain of
the tissues with which it has been in contact is in most
cases perceptible. The want of smell, however, is no
proof of the absence of the acid; which may still be
present in considerable quantity, either diluted with a
comparatively large amount of liquid, or even more or
less completely neutralized by magnesia, or some other
alkaline substance that may have been administered as an
antidote. In the latter case, the liquid may be neutral,
or nearly so, to test paper.
828. In order to detect nitric acid, the liquid, after filb




316   NITRIC ACID IN  ORGANIC MIXTURES.
tration, may, if acid, be neutralized with carbonate of
potash, and evaporated to dryness at a gentle heat. The
nitric acid will thus be obtained in combination with
potash, forming nitrate of potash, which will be deposited
in needle-shaped crystals when most of the water is expelled; unless, indeed, the crystallization is prevented
by the admixture of much animal or other matters.
829. The greater part of the saline residue thus obtained, is to be dissolved in as small a quantity of water
as possible, and the solution placed in four test-tubes, for
the following experiments:(a) The first portion is mixed in a small test-tube, with
a few drops of strong sulphuric acid; after which a clean
strip or two of copper, or a little roll of copper wire, is
dropped in, and, if necessary, a gentle heat applied. If
nitric acid is present, orange fumes of nitrous acid will
be given off, the smell of which may generally be recognized, even when in too small quantity to be apparent
to the eye.
(b) To the second portion add a few drops of hydrochloric acid, and put a small fragment or two of gold
leaf into the mixture. If nitric acid is present, the gold
leaf will be partially or wholly dissolved; and the presence of gold in the solution may be proved by protochloride of tin causing with it a purple precipitate.
(c) The third portion is to be acidified with a few drops
of strong sulphuric acid, and as soon as the mixture is
cool, a small crystal of protosulphate of iron is dropped
in; when, if nitric acid is present, the liquid round the
crystal will assume a brown color, which disappears on
boiling the mixture.
(d) Mix the remaining portion of the solution with
sulphuric acid, and add a drop of dilute sulphate of indigo, sufficient to give the liquid a pale blue color. If
nitric acid is present, the color of the indigo will disappear, especially on warming the mixture.




OXALIC ACID.                   317
SECTION II.
Detection of Nitric Acid in Stains on Clothing.
830. Stains occasioned by the action of nitric acid on
woollen cloth are usually of a brown or yellowish color,
and, unlike those caused by sulphuric acid (817), become
in a short time dry and extremely rotten. The yellow
color of the nitric acid stain is changed to orange by potash or ammonia, which will generally restore the original
color of fabrics stained by hydrochloric or sulphuric acid.
If recent, the acid may generally be detected in them,
by boiling the stained part with a little water, neutralizing with potash, and applying the tests mentioned in
paragraph 829, but if any considerable time has elapsed
since the production of the stain, it is probable that all
traces of the acid will have disappeared, partly by evaporation, and partly by decomposition, occasioned by
contact with the organic matter.
CHAPTER XI.
OXALIC ACID (HO, 203).
SECTION I.
Detection of Oxalic Acid in Organic Mixtures.
831. BEFORE proceeding to apply the several tests for
oxalic acid in the contents of a stomach, vomited matters,
or other mixtures containing organic matter, it is advisable first to separate the latter, since its presence
might interfere with the action of some of the reagents.*
If lime or magnesia has been used as an antidote, the
oxalic acid, if present, will be either wholly or in part
in the form of an insoluble oxalate; so that, in that case,
* Separation by dialysis will be found of the greatest use in the
case of oxalic acid.
27*




318   OXALIC ACID IN ORGANIC MIXTURES.
it is necessary to boil the sediment with a solution of
carbonate of' potash, whereby the acid will be brought
into solution as oxalate of potash (KO,C20,); an insoluble carbonate of the earth being at the same time formed.
CaO,C203 +- KO, CO      0 KO,C203 - CaO,CO,.
832. The suspected mixture is first boiled, to insure
the solution of the whole of the acid contained in it, and
filtered, if necessary, from any solid residue. A solution
of acetate of lead is then added as long as it causes any
precipitate, which will throw down the oxalic acid in the
form of the insoluble oxalate of lead (PbO,C203), together
with the greater part of the soluble organic matter. The
precipitate thus formed is digested for an hour or two in
dilute hydrosulphate of ammonia, and the mixture then
evaporated to dryness on a water-bath. The lead is in
this way separated, in the form of the insoluble black
sulphide, from the acid; which in combination with the
ammonia (oxalate of ammonia), may be dissolved out
with water, leaving the sulphide undissolved, together
with the greater part of the organic mater.
833. The solution thus obtained is then filtered, and
examined in the following manner for oxalic acid:(a) A solution of sulphate of lime, or a very dilute
solution of chloride of calcium, added to a portion of the
solution, gives, if any oxalic acid is present, an immediate
white precipitate of oxalate of lime (CaO,CO,+2Aq),
which readily dissolves in dilute nitric or hydrochloric
acid, but is insoluble in acetic or tartaric acid.
(b) If the oxalate of lime formed in a, be gently ignited on platinum foil, it will be converted into carbonate,
with little or no blackening. The carbonate of lime thus
produced will be found to effervesce when treated with
dilute hydrochloric acid, and if a little of it be strongly
ignited for a short time, it will be still further decomposed, and the carbonic acid expelled; after which the
residue of caustic lime will, when placed on a piece of
moistened turmeric paper, change the yellow color to
brown.
(c) Test another portion of the solution with nitrate of
silver. If oxalic acid is present, a white precipitate of




HYDROCYANIC ACID.                   319
oxalate of silver (AgO,CO2) will be produced, which is
soluble both in nitric acid and ammonia. If the precipitate be dried, and gently heated on platinum foil, it
will be decomposed with a slight puff, leaving a residue
of metallic silver.
SECTION II.
Quantitative Determination of Oxalic Acid.
834. The quantity of oxalic acid in the liquid may be
estimated in the following manner. The solution is first
acidified with a little acetic acid, in order to decompose
any soluble carbonate that may be present. A solution
of chloride of calcium is then to be added as long as it
causes any precipitate; and the mixture is boiled and filtered. The precipitate, after being washed on the filter,
is dried, and gently ignited in a counterpoised crucible.
It is then, after cooling, moistened with a solution of carbonate of ammonia, and again heated a little below redness, in order to expel the excess of the ammoniacal salt,
which was added for the purpose of supplying carbonic
acid to any lime that may have been rendered caustic during the first ignition (633b).
885. The oxalate of lime is thus wholly converted into
carbonate; which is to be weighed, and from its weight
that of the oxalic acid may be calculated as follows:Ate. wt. of   t of carb lime  Wt. of oxalic acid
bonate of lime  crystallized    obtained.    in the quantity of
oxalic acid.            liquid employed.
e —--— 3  _._______.j E              _~___ __,_.
50:   63::    a  x
CHAPTER XII.
HYDROCYANIC (OR PRUSSIC) ACID (HCy).
836. THE presence of hydrocyanic acid, even when
largely diluted, may usually be detected by its peculiar
and characteristic odor, somewhat resembling that of oil
of bitter almnonds.  Great caution is necessary not to




320              HYDROCYANIC ACID.
inhale more than the smallest quantity of the vapor,
since headache and other unpleasant symptoms may be
occasioned by merely smelling it, even when in a highly
diluted state.
837. It must be remembered, in cases of suspected
poisoning with this acid, that no time should be lost in
applying the tests for its presence; since it rapidly volatilizes, and, unless carefully protected from the air, disappears entirely in the course of a few days. The facility with which the acid is decomposed when in contact
with putrefying organic matter also prevents its detection
after some time has elapsed.
SECTION I.
Detection of Hydrocyanic Acid in Organic Mixtures.
I. Detection of the acid in the state of vapor.
838. Very small traces of the acid may be detected by
one or other of the following tests, which may be readily
applied to any liquid or mixture suspected to contain it.
There is also this advantage in being able to identify it
without going through the process of distillation at a
higher temperature, viz., that while the tests for the
vapor which I am about to describe are equally, or even
more delicate than those for the liquid after distillation,
the chances in favor of the spontaneous formation of the
acid by the decomposition of the organic matter are
greatly diminished.
839. A little of the mixture suspected to contain the
poison, slightly acidified, if neutral or alkaline, with
dilute sulphuric acid, may be placed in a watch-glass,*
over which another similar watch-glass is to be inverted,
having been previously moistened with a drop or two of
a solution of nitrate of silver, care being taken that none
of the latter is allowed to run into the lower glass. The
* Since, in medico-legal investigations, it is not desirable to transfer the liquid from one vessel to another if it can be avoided, it is
better to invert the watch-glasses moistened with the reagents over
the mouth of the bottle in which the contents of the stomach, &c.,
have been placed as soon as removed from the body. Of course,
pieces of glass might be used instead of watch-glasses.




DETECTION OF HYDROCYANIC ACID.   321
glass containing the suspected solution is then very gently
warmed by holding it in the hand; when, if any hydrocyanic acid is present, it will volatilize into the upper
glass; where, on coming in contact with the silver solu.
tion, it will form a white film of cyanide of silver (AgCy).
This test is very delicate; but as a somewhat similar
effect might be produced by hydrochloric acid, it is
always advisable to confirm the result by the following
experiments:840. A little of the suspected mixture, previously
acidified, if necessary, with a little dilute sulphuric acid,
is put into a watch-glass, over which is placed another
glass moistened with a drop or two of solution of potash.
The hydrocyanic acid, if present, gradually evaporates
into the upper glass, where it combines with the potash,
forming in solution a little cyanide of potassium. This
is then mixed, first with a drop of a solution of protosulphate of iron (which should have been exposed to the air
for a short time, so as to have become partially converted
into the persulphate),* and afterwards with a drop or two
of dilute hydrochloric acid, which should be added in
slight excess. Should any hydrocyanic acid have been
present in the mixture, a blue precipitate of Prussian
blue will be immediately formed, the appearance of which
may be considered as a sure proof of the existence of
the acid. This experiment is commonly known as Scheele's
or the iron test.
If the hydrocyanic acid be present in small quantity,
no precipitate of Prussian blue will be seen at first, but
a green liquid will be formed which will deposit flakes
of Prussian blue on standing. It is always desirable to
compare the result with that obtained by mixing together
in another watch-glass, the potash, iron-salts, and hydrochloric acid in the same proportions as were employed
in the test.
841. The following test, commonly known as Liebig's
test, which is perhaps the most delicate of all, may also be
applied. A little of the suspected fluid slightly acidified, if
* Or a drop of perchloride of iron may be added as well as the protosulphate.




322           HYDROCYANIC ACID.
necessary, is put into a watch-glass as before, and over
this another watch-glass is inverted, containing a drop
of hydrosulphate of ammonia, which for this purpose
should contain an excess of sulphur, and consequently
have a yellow color. The glasses may be allowed to
remain together for about a quarter or half an hour;
after which the upper one is removed, and placed on a
water-bath, until the hydrosulphate of ammonia is evaporated to dryness. Should any hydrocyanic acid have
been present in the liquid, some of its vapor will have
combined with the hydrosulphate, with which it would
form sulphocyanide of ammonium. The residue left
after the evaporation of the drop is now to be moistened
with a dilute solution of persulphate or perchloride of
iron; which, in case any sulphocyanide of ammonium
had been formed, or, in other words, in case any hydrocyanic acid had been present in the suspected mixture,
will immediately produce a blood-red color, owing to the
formation of sulphocyanide of iron. This color is bleached
by perchloride of mercury (corrosive sublimate), and is
thus distinguished from that caused by acetate or meconate of iron.
II. Detection of Hydrocyanic Acid in Solution.
842. The mixture suspected to contain the poison is to
be distilled in a retort heated on a water-bath, the receiver being kept cool by immersion in cold water, or
in a freezing mixture composed of ice and salt, or of
equal weights of nitrate of ammonia and water. When
about one-eighth part of the liquid has passed over into
the receiver, the distillation may be stopped. Should
the mixture, previous to distillation, be neutral, or at all
alkaline to test paper, it should be slightly acidified with
dilute sulphuric acid, in order to disengage the hydrocyanic acid from the ammonia, or other bases which may
be present, and which would tend to prevent the distillation of the acid at the low temperature employed.
The presence of hydrocyanic acid in the distilled liquid
may be ascertained by the following peculiarities:843. Unless the quantity of acid be very minute, the




DETECTION OF HYDROCYANIC ACID.   323
peculiar odor, resembling that of oil of bitter almonds,
will probably be apparent.
844. Test a little of the distilled liquid with a solution
of nitrate of silver. If hydrocyanic acid is present, a
white precipitate of cyanide of silver is produced, which
is soluble in ammonia and in hot nitric acid, but insoluble
in the cold acid.
845. The cyanide of silver should be collected upon a
filter, washed as long as the washings are acid, and dried
at a gentle heat. It is then to be subjected to the follow-.ing tests: —
846. Place a very small fragment of iodine at the
bottom of a small tube closed at one end, and above it
as much as can be spared of the supposed cyanide of silver. Apply a very gentle heat, by holding the tube at
some distance above a flame, when iodide of cyanogen
will be formed, and will condense on the cool part of the
tube in very fine white needles.
AgCy   12 I= AgI + CyI.
(If a very little cyanide of silver be used, it is well to
cover it with a layer of carbonate of soda, to retain any
excess of iodine.)
847. File off that portion of the tube which contains
the sublimate, and warm it in a test tube, with a little
dilute yellow hydrosulphate of ammonia in which it will
dissolve. Evaporate the solution on the water-bath, and
test the residue with perchloride of iron (841).
If a sufficient quantity of the cyanide of silver can be
obtained, another sublimate of iodide of cyanogen may
be made and tested by dissolving in potash and applying
the Prussian blue test (840).
848. Boil a little of the cyanide of silver with yellow
hvdrosulphate of ammonia, filter, evaporate on a waterbath, and apply Liebig's test (841). A very small particle of cyanide of silver may be tested in a watch-glass,
by moistening with a drop of' yellow sulphide of arnmonium, evaporating on the water-bath, and testing with
perchloride of iron.
* For this excellent test we are indebted to MM. Henry and Humbert.




324             HYDROCYANIC ACID.
849. Add to a little of the distilled liquid in a test
tube, first a little solution of potash: then a drop or two
of a solution of protosulphate of iron, containing also
a little persulphate (840); and lastly, a slight excess of
dilute hydrochloric acid. If the liquid contains hydrocyanic acid, a precipitate of Prussian blue will be immediately produced; or if only a small trace is present, a
few hours may elapse before it becomes apparent.
850. Mix another portion of the distilled liquid with
a few drops of yellow hydrosulphate of ammonia, evaporate the mixture to dryness on a water-bath, and test as
in 841.
851. The evaporation to dryness in this experiment is
necessary, in order to expel the excess of hydrosulphate
of ammonia; which would otherwise form with the iron
solution a black precipitate of sulphide, and thus obscure
the appearance of the characteristic red color.* During
the evaporation the heat rmust be kept very moderate,
lest any of the sulphocyanide of ammonium that may be
formed by the action of the hydrocyanic acid on the hydrosulphate should be decomposed.
SECTION II.
Quantitative Determination of Hydrocyanic Acid.
852. The quantity of hydrocyanic acid contained in an
organic mixture may be ascertained with sufficient accuracy for most purposes by distilling the acid (842), and
precipitating the distilled liquid by means of nitrate of
silver. The precipitated cyanide of silver is washed and
dried in a hot water oven until it ceases to lose weight.
From the weight of the cyanide thus obtained, that of
the anhydrous hydrocyanic acid (iCy) may be calculated
as follows:Ate. wt.   Ate. wt. of  Wt. of cyanide  Wt. of hydrocyanic
of cyanide  hydrocyanic   of silver   acid in the quantity of
of silver.    acid.  obtained.    mixture employed.
134:   27::    a:       x
* Which may still be rendered evident by filtering the liquid.




OPIUM.                     325
CHAPTER XIII.
OPIUM.
853. OF the several compounds contained in, and peculiar to opium, two only, morphia (C,,4H,,NO6) and meconic acid (3HO,CH40,,), are possessed of sufficiently
characteristic properties to enable us to identify them
when mixed with other matters; the tests for these substances, moreover, are not particularly delicate, so that
it is difficult, and not unfrequently impossible, to detect
small traces of them. In cases of poisoning with opium
it is seldom that any traces of it can be found in the
contents of the stomach; so that the tissues of the stomach itself, the intestines, and also any vomited matters,
ought to be carefully examined for the poison.
Detection of Opium in Organic Mixtures, Tissues, &c.
854. If the substance to be examined is liquid or semifluid, it should first be evaporated to dryness, or nearly
so, on a water-bath. If solid, the suspected substance
may be cut into thin slices. The residue left after evaporation, or the sliced solid matter, as the case may be, is
then to be digested for an hour or two, with the aid of a
gentle heat, in a flask or dish placed on a water-bath,
with a small quantity of water containing a little acetic
acid. The mixture is filtered, and the clear liquid, containing a slight excess of acetic acid, is treated with a
solution of acetate of lead (PbO,CH'303) as long as any
precipitate is produced.  The meconic acid, if present, is
thus thrown down in combination with oxide of lead,
forming meconate of lead (3PbO,C411H0,); while the morphia remains in solution in combination with acetic acid
(acetate of morphia), together with any excess of acetate
of lead that may have been employed. The mixture is
26




326                  MORPHfA.
warmed (not boiled, since by boiling some of the meconic
acid might become decomposed) and, when again cold, is
filtered.
855. The clear solution may first be examined for
morphia; reserving the precipitate for subsequent examination.
856. A current of hydrosulphuric acid (sulphuretted
hydrogen) is passed through the solution, until the latter
smells distinctly of the gas, in order to decompose the
excess of acetate of lead. The precipitated sulphide of
lead is separated by filtration from the solution; which
latter, after boiling, and if necessary concentrated by
evaporation, is to be examined for morphia by means of
the following tests:857. Place a drop or two of the concentrated solution
on a strip of glass, and add a drop of ammonia. The
morphia will be precipitated in the form of minute needleshaped crystals, which may be examined under the microscope.
858. Mix a small quantity of the solution in a testtube or watch-glass, with enough solution of carbonate
of soda to give it a decided alkaline reaction, and stir the
mixture with a glass rod, rubbing the sides of the vessel.
A crystalline precipitate of morphia will be deposited
on standing, especially upon the lines of friction. Should
the carbonate of soda produce an immediate flocculent
precipitate (of the phosphate or carbonate of lime, for
example), this should be filtered off immediately, before
the solution is stirred with the glass rod, and should be
reserved for further examination.
859. If any crystalline precipitate has been produced by
the carbonate of soda, it must be collected upon a small
filter (reserving the filtered liquid) and washed with very
small quantities of cold water as long as the washings
are decidedly alkaline (these washings are to be mixed
with the filtered liquid). The filter is then carefully
spread out upon a glass plate, and a drop of solution of
perchloride of iron placed, with a glass rod, upon a part
of the precipitate; if morphia be present, an indigo-blue
color will be produced.  Another particle of the precipi



MORPHIA.                     327
tate may be touched with a drop of a strong nitric acid,
which tinges morphia of an orange red color-.*
860. The solutiont in which carbonate of soda has not
caused any crystalline precipitate, or which has been filtered from the precipitate, is now evaporated to dryness
on a water-bath, and heated with alcohol, which would
dissolve the morphia; on filtering the solution and evaporating to dryness on the water-bath, the niorphia will be
left, and may be tested as in 859.
861. The flocculent precipitate produced by carbonate
of soda (858) may be examined by washing it with a
little hot alcohol to dissolve the morphia which may then
be separated by evaporation and tested as in 859.
862. The precipitate, supposed to contain meconate of
lead (854), is now to be mixed with water in a beaker
glass; and while suspended in the liquid, treated with a
current of hydrosulphuric acid, the mixture being stirred
occasionally. The meconate of lead is thus decomposed;
the black sulphide of lead being precipitated, while the
meconic acid, if present, remains in solution. The mixture is filtered to separate the sulphide of lead, and the
clear liquid is gently warmed (not boiled (854),) in order
to expel the excess of hydrosulphuric acid; and, if necessary, concentrated by evaporation on a water-bath.  The
meconic acid, if present in sufficient quantity, may then
be detected by the following tests:863. A solution of perchloride of iron gives the liquid,
in case meconic acid is present, a bright red color, owing
to the formation of meconate of iron. The color closely
resembles that caused in solutions of iron by the sulphocyanides, from which it may be distinguished by not being
decolorized by a solution of bichloride of mercury (841).
It is, however, destroyed by boiling nitric acid, chloride
of tin, and the caustic alkalies.
864. Solutions of acetate of lead, chloride of barium,
and nitrate of silver, produce white precipitates of meconates, which are all soluble in an excess of nitric acid.
* Concentrated sulphuric acid, to which 0-004 per. cent. of nitric
acid (NO5) has been added, gives a violet purple color when gently
heated with morphia or the hydrochlorate (Erdmann).
t If possible the solution should be set aside for some hours in order to allow the morphia to crystallize out.




328                 STRYCHNIA.
CHAPTER XIV.
STRYCHNIA.
865. STRYCHNIA (C421'22N204) is the poisonous alkaloid
contained in nux vomica and other plants of the strychnos
tribe. Although a very minute quantity of strychnia is
sufficient to cause death, the symptoms to which it gives
rise are usually so well marked, and the tests by whici
it may be recognized are so characteristic and delicate,
that less difficulty is experienced in deciding upon the
question of its administration than in the case of most
other vegetable poisons.
Detection of Strychnia in Organic Mixtures, Tissues, &c.
866. The matter under examination, which, if solid,
should be cut into shreds or slices, is digested, for about
an hour, in a dish placed upon a water-bath, with dilute
hydrochloric acid (1 part of the strong acid with 10 parts
of water). The solution is then rendered pretty clear by
filtration through muslin, or paper, evaporated on a waterbath to as small a bulk as convenient, and rendered
strongly alkaline by solution of potash. The alkaline
solution is poured into a narrow stoppered bottle, and
shaken with about an equal volume of ether for several
minutes; on standing, the ether will rise to the surface,
holding the strychnine in solution. The ethereal layer
is drawn off with a small syphon or pipette, and evaporated to dryness in a small capsule placed on the waterbath. Very minute particles of the solid residue may
then be taken on the point of a knife, and examined for
strychnia by the following tests:867. The extremely bitter taste of strychnia is perceptible even when a very minute quantity is examined.
868. A  particle of the suspected substance is placed




ST-RYCHNIA.                     329
upon a piece of white porcelain, and beside it, but not
touching it, a drop of strong sulphuric acid is placed
with a glass rod. A trace of solution of chromate or
bichromate of potash is introduced, by a glass rod, into
the drop of sulphuric acid, and the particle supposed to
contain strychnia is then pushed into it. A fine violet
blue color should then be produced, which soon changes
into red.*
869. Another particle of the substance is moistened
with strong nitric acid, and a very minute quantity of the
peroxide (brown oxide) of lead is added. Violet streaks
should arise from the particles of the peroxide, and
should gradually pervade the liquid, ultimately changing
to red.
870. If the results obtained by these tests should not
be satisfactory, in consequence of some fatty or other
organic matter having also been dissolved by the ether
and left with the strychnine on evaporation, the remainder
of the suspected residue (866) in the capsule, should be
moistened with strong sulphuric acid, and heated for some
time upon the water.bath, when the extraneous organic
matters will be carbonized, and the strychnia converted
into a sulphate. The carbonaceous mass is treated with
water, filtered, the clear solution mixed with a slight
excess of ammonia, and shaken with about one-sixth of
its volume of chloroform (for which ether may, in case
of need, be substituted).t  When the chloroform, holding the strychnia in solution, has fallen to the bottom of
the liquid, the latter is drawn off and the chloroform
evaporated upon a water-bath, when the strychnia will
be left and may be identified by the tests described in
868, 869.
* Although the presence of any considerable proportion of morphia
interferes with'the detection of strychnia, the separation of the two
alkaloids is so easily effected by ether or benzole, which will readily
dissolve strychnia, but scarcely morphia, that there is no danger of
strychnia being overlooked from this cause.
t Benzole, which is lighter than water, and less volatile as well as
cheaper than chloroform or ether, may also be employed for the extraction of strychnia, though it is not so good a solvent for it as chloroform.
28*




330                  NICOTIA.
CHAPTER XV.
NICOTIA.
871. THE poisonous oily alkaloid of tobacco, nicotia,
or nicotine (C,0H7N), has occasionally been employed
with criminal intention, but it is much less likely to be
met with than morphia or strychnia, on account of its
very powerful and characteristic odor.
Detection of Nicotia in Organic Mixtures.
872. This alkaloid may be extracted by a process
similar to that followed in the case of strychnia (866),
viz., by digesting the mixture with dilute hydrochloric
acid, liberating the alkaloid by means of potash, and
removing it from the aqueous solution with ether. On
allowing a few drops of the ethereal solution to evaporate spontaneously, impure nicotia will be left, and may
be recognized by its pungent odor recalling that of tobacco. In order to obtain the nicotia in a pure state,
the ethereal solution must be shaken with water mixed
with about one-fifth of sulphuric acid, which dissolves
the nicotia in the form of sulphate. The ether is then
poured off; and the aqueous solution of sulphate of nicotia is shaken with a little more ether to remove any fatty
matters which may be present. It is then rendered alkaline by potash, and again shaken with ether, the ethereal layer containing the nicotia being afterwards allowed
to evaporate spontaneously, when oily drops of nicotia
are left, and may be recognized by the smell, especially
when gently heated. If ammonia be present, it may be
removed by exposing the nicotia under an exhausted receiver containing a dish of strong sulphuric acid.




PHOSPHORUS.                  331
CHEAPTER XVI.
DETECTION OF PHOSPHORUS IN CASES OF POISONING.
873. THE comparative frequency of accidental poison.
ing by phosphorus matches in the hands of children, together with the circumstance that a phosphorus poison
for vermin is now in very common use, render it necessary that the medical chemist should be able to obtain
evidence of its presence in organic mixtures. If possible
the vomited matter should be especially examined, as
they have been found to contain the largest proportion
of phosphorus.
874. If the substance to be examined has not been
long exposed to the air, it may still contain phosphorus
in the free state, but in most cases oxidation will have
converted the phosphorus into phosphorous acid (PO3),
or possibly even into phosphoric acid (PO,). Since this
last is a normal constituent of the body and of the food,
it would afford no evidence of the administration of
phosphorus, but fortunately, unless after prolonged exposure, either phosphorous acid or phosphorus itself can
be detected whenever this element has been taken into
the system.
875. The organic matter should first be examined as
to its odor, that of phosphorus being very characteristic,
and as to its luminosity in the dark. It should also be
carefully looked over to ascertain if any solid particles
of the phosphorized composition can be detected.
876. The suspected matter is then placed in a flask,
and acidulated with dilute sulphuric acid, a little water
being also added if necessary. The flask is connected
by means of a cork with a bent glass tube passing through
a wide tube (having a perforated cork at each end) through
which a stream of cold water can be kept trickling. On




332                PHOSPHO RS.
applying a moderate heat to the flask, in a darkened
room, the condensing vapors should exhibit a phosphorescent appearance. The liquid which distils over may
possibly contain white finely divided phosphorus. If it
be at all turbid it should be shaken, in a tall vessel, with
bisulphide of carbon, which will dissolve the phosphorus
and sink to the bottom. On allowing the bisulphide of
carbon to evaporate spontaneously, it will leave the
phosphorus, often in a spontaneously inflammable condition. If no free phosphorus has been detected, both the
distilled liquid and that remaining in the flask must be
examined for phosphorous acid by the following process:
877. The liquid to be tested having been acidulated
with sulphuric acid, is placed in a flask, together with a
few fragments of pure zinc. A cork with a bent tube is
then attached so that the evolved hydrogen may be passed
through a solution of nitrate of silver. A strip of filterpaper moistened with nitrate of silver may also be suspended some distance above the surface of the liquid in
the flask. Should any inconvenience be caused by the
frothing, a little alcohol may be poured upon the surface
of the liquid. If any phosphorous acid be present, phosphuretted hrydrogen (PHE) will be evolved, and will
produce a dark precipitate in the solution of nitrate of
silver, and a mingled gray and yellow stain upon the
filter paper, which will become bright yellow when dipped
into a little strong nitric acid.  (Sulphuretted hydrogen
would merely blacken the nitrate of silver, and the stain
would be dissolved by the acid without turning yellow.)
The dark precipitate (phosphide of silver, Ag3P) is collected upon a small filter, washed, dissolved in a little
hot nitric acid, and the solution evaporated to dryness.
On adding a little water, and a trace of ammonia upon
the end of a glass rod, the yellow precipitate of phosphate
of silver (3AgO,PO,) will be produced. The characteristic odor of phosphuretted hydrogen should also be
looked for in this experiment.




DETECTION OF ALCO HOL.            333
CHAPTER XVII.
DETECTION OF ALCOHOL IN ORGANIC MIXTURES.
878. IN cases where alcohol (C04,H60) in any form hasbeen taken shortly before death, it may generally be detected in the contents of the stomach. The odor having
been carefully noticed, the organic matter, mixed with a
little water if necessary, should, if acid, be exactly neutralized with potash, and distilled, by the heat of a waterbath, in a flask or retort connected with a tube carefully
cooled in order to condense the vapors.. When a sufficient
quantity of the liquid has distilled over, it may be examined for alcohol by the following tests:879. Observe whether it has the smell and taste of
alcohol. Dip a glass rod into it and see if it will burn.
880. Mix a small portion with dilute sulphuric or hydrochloric acid, and add a drop of solution of bichromate
of potash (KO,2CrO3). On applying heat to the mixture,
the presence of alcohol would be indicated by the change
of the orange color of chromic acid (CrO,) into the green
of oxide of chromium (Cr203), and by the odor of aldehyde
(C04,40,) at the mouth of the tube.
881. The remainder of the alcoholic distillate may be
placed in a tube, and dry powdered carbonate of potash
added to it, in small portions as long as it is dissolved.
The water will be thus taken up by the carbonate of
potash, and the alcohol will rise to the surface, and will
now be found to be inflarnmable, although it may have
been too much diluted when previously tried.




334           DETECTION OF POISONS.
CHAPTER XVIII.
GENERAL SYSTEMATIC COURSE FOR THE DETECTION OF
POISONS IN ORGANIC MIXTURES.
882. ALTHOUGH it rarely happens that an organic
mixture is submitted to examination without some clue
which enables the chemist to limit the inquiry to a very
few poisons, still such a case should be provided for, and
it is here proposed to give an outline of a systematic
course for the detection of the leading poisons, in three
divisions, referring to cases where (1) the poison is believed to be metallic, (2) it is believed to be an organic
poison, and (3) nothing whatever is known about it.
Alcohol, phosphorus, opium, and hydrocyanic acid will
not be included in this course, since they at once afford
indications of their presence, and may be detected accordi'ng to the directions already given.
THE POISON IS BELIEVED -TO BE METALLIC..xaminationrfor Arsenic, Antimony, Mercury, Copper, Lead,
Zinc, Barium, Silver, Bismuth.
883. The solid portions of the mixture having been
as finely divided as possible, with a sharp knife or scissors, the whole is heated (for about an hour) in a porcelain dish placed upon a water bath, with a mixture of six
measures of water and one of hydrochloric acid,* to which
chlorate of potash is added by degrees, with constant
stirring, until the solid has disintegrated, and the liquid
is sufficiently thin for filtration. It is then filtered, the
insoluble part is washed several times with water (the
* If there be much liquid, less water must be added so that the
acid may form about a sixth of the whole.




IN ORGANIC MIXTURES.               885
washings being mixed with the filtrate), and is then set
aside for further examination (892).
884. The filtered liquid is evaporated on a water-bath,
to a small bulk, and subjected to electrolysis as directed
in 753. After the passage of the current has been con.
tinued for about an hour (during which the exit tube has
been heated in order to detect arsenic and antimony) (753,
766), about half a drachm of a strong solution of washed
sulphurous acid is poured down the funnel tube; the exit
tube having been first changed if any deposit should
have been formed in it.
885. After the current has passed for another half
hour, the electro-negative platinum plate is removed
from the decomposing cell, without suspending the current, and washed with a little distilled water. The liquid
in the cell is reserved for subsequent examination (888).
886. The appearance of the deposit upon the electronegative plate having been carefully observed, it is boiledl
with a little dilute yellow  hydrosulphate of ammonia,
which will dissolve the antimony, to be detected in the
solution according to 763 (e).
887. The plate is again well washed, and boiled with
dilute nitric acid. The solution is boiled down (in a
test-tube) to a very small bulk, and mixed with an excess of ammonia. The presence of copper will be indicated by the blue color. Hydrochloric acid is very carefully added till the solution is slightly aci(l, and it is then
largely diluted with water. A milkiness will be produced if bismuth be present. The liquid is again evaporated to a small bulk, rendered clear by adding a little
hydrochloric acid, and boiled with a strip of bright
copper, to detect mercury (770, 771). In  case any
mercury should have been left upon the platinum in the
form of sulphide, the plates may be again boiled with
dilute nitric acid and a drop of hydrochloric acid (taking
care not to dissolve much of the platinum). The solution
is boiled down to a small bulk, mixed with excess of
ammonia, then with hydrochloric acid in excess, and
boiled with copper.
888. The liquid which has been subjected to electrolysis (885) is now evaporated at a moderate heat, until




336            DETECTION  OF POISONS
the organic matter is so far carbonized that a small portion, when diluted with water, and filtered, yields a
nearly colorless solution.  The whole is then mixed
with a few drops of hydrochloric and nitric acids, heated
to boiling, again diluted and filtered. The carbonaceous
residue is washed and reserved for further examination
(891).
889. The filtrate and washings are saturated with sulphuretted hydrogen, boiled, again saturated with sulphuretted hydrogen and set aside in a warm place, in a
covered vessel, for several hours. Any precipitate, except sulphur, which may have been deposited, is filtered
off; washed, and examined for metals according to the
general method followed in qualitative analysis.
890. The solution filtered from this precipitate is
evaporated to a small bulk, and mixed with an excess of
ammonia.  If this should produce a precipitate (generally
consisting of earthy phosphates or peroxide of iron), it is
filtered off, and the solution mixed with a little hydrosulphate of ammonia to precipitate any zinc as sulphide,
which may be tested by the blowpipe (803c),
891. The carbonaceous residue from  888 is dried,t
incinerated, and examined together with the other incinerated residue from 883.
892. The residue left undissolved by hydrochloric
acid and chlorate of potash in 883 is dried and incinerated
at a low red heat. The ash is mixed with that obtained
in 891, and boiled with nitric acid diluted with  two
volumes of water.  The solution is filtered and examined
for metals as usual in qualitative analysis.
893. Any portion of ash left undissolved by the nitric
acid is washed, dried, and, if still retaining any carbon,
again incinerated. The residue which might possibly
contain barium (as sulphate), silver (as chloride), and
* If this precipitate is very dark and impure, it must be dissolved
in a mixtare of hydrochloric and nitric acids, the solution evaporated
to dryness, the residue heated till all organic matter is destroyed, and
dissolved in nitric acid. The solution is mixed with excess of ammonia, filtered, if necessary, and tested with hydrosulphate of amInonia.
t A small charcoal fire will be found very convenient in these
incinerations.




IN  ORGANIC  MIXTURES.                 337
lead (as sulphate), is fused with three or four parts oi
carbonate of soda in a porcelain crucible.  The fused
mass having been boiled with water, the residue is washed
till the washings leave nothing on evaporation, and dissolved in hot dilute nitric acid. The nitric solution is
tested (1) for silver with hydrochloric acid, which would
give a white precipitate, soluble in ammonia (2), for
barium with sulphate of lime (white precipitate*) and
hydrofluosilicic acid (white crystalline precipitate), (3)
for lead with dilute sulphuric acid (white granular precipitate), and hydrosulphuric acid (purplish black precipitate).
THE POISON IS BELIEVED TO BE ORGANIC.
Examination for Oxalic Acid, Morphia, Strychnia, Nicotia
and Conia.
893a. The organic mixture, of which the solid portions
have been as finely divided as possible, is digested in
water acidulated  with hydrochloric acid, for an hour
or two, in a dish placed upon a wash-bath. The solution
is then filtered, first through muslin, and afterwards
through paper, and evaporated upon the water-bath to
a small bulk.
894. A small portion of this solution is tested for
oxalic acid by adding a little chloride of calcium, then
ammonia in excess, and finally, acetic acid in excess. If
any white crystalline precipitate of oxalate of lime be left
undissolved by the acetic acid, the larger portion of the
solution must be examined for oxalic acid according to
Chapter XI.
895. The remainder of the solution from 893a is rendered pretty strongly alkaline by potash, and shaken
with four or five times its volume of ether.t After
* If this precipitate be collected on a filter, well washed, and heated
on a platinum wire moistened with hydrochloric acid, in the inner
blowpipe flame, it will tinge the outer flame bright green.
t Uslar and Erdmann have recommended amylic alcohol as a solvent for the poisonous alkaloids, but the advantage with which its
employment in certain cases may be attended is in great measure counterbalanced by the very disagreeable and injurious character of its
vapor.
29




338        DETECTION  OF POISONS," ETC.
standing for some time, the ethereal layer is poured off
or drawn off with a small syphon or pipette.
896. The ethereal solution is poured into a dish and
allowed to evaporate spontaneously. If either nicotia
or conia be present, it will be left in oily drops which
will evolve the powerful odor of the base when gently
heated on the water-bath. If any solid residue be left
by the ether, it must be examined for strychnia and morphia. For this purpose it is dissolved in a very little
dilute hydrochloric acid, filtered, if necessary, and the
solution rendered alkaline with carbonate of soda, briskly
stirred, and set aside for an hour or two. If any crystalline precipitate is formed, it must be examined for
strychnia and morphia according to 868, 869, 859. The
solution in which carbonate of soda has failed to produce
a precipitate, or which has been filtered from the precipitate, is evaporated to dryness on a water-bath, and the
residue gently heated with absolute alcohol. The alcoholic solution is evaporated to dryness, and the residue
tested for strychnia and morphia.
897. The aqueous layer separated in 895 is slightly
acidified with hydrochloric acid, and evaporated to dryness on the water-bath.  The residue is heated with
strong alcohol for some time. The alcoholic solution is
filtered and evaporated to dryness on the water-bath.
The residue is redissolved in a very little water, the solution briskly stirred with a slight excess of carbonate
of soda,* and the further examination conducted precisely as in 896.
NOTHING IS KNOWN OF THE NATURE OF THE POISON.
898. In this case, the first part of the process must be
conducted on the supposition that the poison is organic
(893a); the residue left undissolved by alcohol in 896,
897, as well as so much of the precipitate produced by
carbonate of soda as is not consumed in testing for alka* If oxalic acid be present, it might go down in this precipitate as
oxalate of lime. The remainder of the oxalic acid will be found as
oxalate of soda in the residue left by absolute alcohol in extracting
the morphia.




SEPARATION OF POISONS BY DIALYSIS.  339
loids, must be dissolved in hydrochloric acid, mixel with
the original organic matter left undissolved by the hydrochloric acid (893a), and the examination for metallic
poisons proceeded with as in 883.
CHAPTER XIX.
SEPARATION OF POISONS FROM ORGANIC MIXTURES
BY DIALYSIS.
899. THE important observation made by Mr. Graham
that crystallizable bodies will pass in a state of solution
through membranous and other diaphragms which will
not permit the passage of the amorphous substances
composing the bulk of most organic mixtures, has been
applied by him to the separation of poisons. As the
process is very simple, easy of execution, and does not
involve any operations which would interfere with the
subsequent application to the same mixture
of any other process for the separation of the   Fig. 82.
poison, it will probably come into very general
use in medico-legal investigations.
This process is, indeed, a refined filtration,
and is applicable instead of that operation, in
all the steps of the separation of poisons
from organic mixtures, with this very great
advantage, that it removes not only substances
mechanically suspended in the liquid, as is
the case with filtration, but also coloring matters, albuminous substances, &c., which so interfere with the application of tests to the liquid obtained by filtration.
900. A circular piece of parchment-paper* (see note
to p. 284) is folded, as in preparing a filter, into a cone,
which should be at least twice as large as is necessary
to contain the mixture under examination. This cone is
placed in the mouth of a cylindrical jar (Fig. 82), (a
* This should have been well soaked in distilled water, and dried
before use.




340  SEPARATION  OF POISONS BY DIALYSIS.
beaker or common tumbler), filled nearly to the brim
with distilled water, the volume of which should be about
eight times that of the organic mixture.
901. The solid portion of the organic matter having
been cut up, and, if it be thought necessary, a little water
having been added to thin the mixture, it may be poured
at once upon the cone of parchment-paper arranged as
above directed. The whole may then be covered with a
bell-glass, or placed in a secure cupboard, and left for as
long a period as can be conveniently allowed to elapse,
if possible, for at least forty-eight hours.  The dcfusate,
as the liquid in the glass is termed, may then be evaporated to a small bulk and examined for the poison by
the appropriate methods, whilst the organic mixture remaininhg upon the cone or dialyser may be subjected to
thle ordinary processes for the separation of poisons from
organic matter.
902. Of course, in cases where there is reason to suspect the presence of hydrocyanic acid, alcohol, or phosphorus, it would not be prudent to subject the mixture
to dialysis until at least a portion of it had been examined
for those poisons.
V!03. If time could be spared, it would evidently be
desirable to dialyse the organic mixture at first without
any addition (except water), since not only would  all
question of impurity in the reagents be avoided, but a
knowledge of the state of the poison, whether soluble or
not, would be thus gained, which might, in many cases,
prove of great service. The mixture might then be
dialysed a second time after digestion with the proper
solvent, such as hydrochloric acid, or that acid with the
addition of chloride of potash*
* The editor has obtained most satisfactory results by this process
in separating arsenious acid, strychnine, morphine, opium, and oxalic.acid (as oxalate of lime). The arsenious acid was separated in some
cases by simply dialysing the organic mixture, in others by digesting
with hydrochloric acid and dialysing, and in others by first digesting
with hydrochloric acid and chlorate of potash. In all cases the diffusate was colorless.




APPENDIX.
WEIGHTS AND MEA.SURES.
Troy or Apothecaries' Weight.
Pound.  Ounces. Drachms. Scruples.    Grains.  French Grammes.
1      12  -=  96  --  288          5760  =   372'96
1  -- 8  --   24    -    480  =    31-08
1  -      3     -    60  =       3885
1   =      20  =       1-295
1  =      0'0647
Avoirdupois Weight.
Pound.    Ounces.    Drachms.    Grains.        French Grammes.
1    16   =    256    -   7000          -   453.25
1   =      16    -     437.5    -       28 328
1   =       27.343 -        1'77
Imperial Measure.
Gallon.    Pints.    Fluidounces.    Fluidrachms.     Minims.
--   8   -          160      -     1280    --      76800
1   -       20    -        160    -        9600
1.8             480
1    -          60
Weight of Water at 62'?, contained in the Imnperial Gallon, 6'c.
Grains.
1 Imperial gallon.....  70000
1     "    pint...                 8750
1     "    flidounce..  =..    4375
1     "    fluidrachm....     54-7
1     "    minim... m..              0'91
Cubic Inches contained in the Isnperial Gallon, 8-c.
Cubic Inches.
1 Imperial gallon.             =...  277276
1     "    pint... =..   34659
1     "    fluidounce...         1'732
1           fluidrachm.. -..    0'2166
1     "      linim.. -..    0(1036
29"




342                         APPENDIX.
FRENCH WEIGHTS AND MEASURES.
Measures of Length.
English Inches.
Millimetre        -    03937
Centimetre  --          39371
Decimetre   -         393710
Metre        -       39-37100   Mil. Fur. Yds. Feet. In.
Decametre   =       393'71000 -  0   0    10   2   9-7
Hecatometre --    3937'10000 =  0   0   109   1   1
Kilometre   -   39371-00000 =  0   4   213   1  10'2
Myriometre -  393710'00000 =  6   1   156   0   6
Mieaszures of Capacity.
English Imperial Measure.
Gal. Pints. F. oz. F. drms. Min.
Cubic Cntimetre }'06102 --    0   0   0    0    1 6-3
or Millilitre
Centilitre   --         61028 =       0   0   0    2    43
Decilitre    -        6-10280 -       0   0   3    3        2
Litre        -       61-()2800 =      0   1  15    1    43
Decalitre    --    610-28000 -        2   1  12    1    16
Ilecatolitre  =    610280000 --   22   0   1    4    40
Kilolitre    =   61028'00000 =   220   0  12    6    24
Myriolitre   =  610280-00000 =  2200   7  13    4    48
Mfeasures of Weight.
English Grains.
Milligramme  -= 0154
Centiaramme  ='          1543
Decigramme   =            1-5432          Avoirdupois.
Gramme         =         154323       Poun. Oun.   Dim.
Decagramme   _          154'3234  --   0    0        5-65
Hecatogramlne         1543'2348  -       0    3      8S5
Kilogramme    -    15432'348   =    2    3           5
Myriogramme  =   154323-480   =   22    1            2




INDEX.
PAng
ACID, arsenious.                                275
detection of, in organic mixtures, &~c.                                36
benzoic.....      35
butic.......     228
butinic..228
butyric...        228, 245
caprylic.......    228
carbonic, estimation of.....     260
cholalic.......     240
choleic......     240
cholic......          239
choloidic..                                                  240
excretolic....                       167
formic.......       26
glycoeholic.....     239
hippuric.......       33
hydrochloric, detection of, in organic mixtures, &c...  313
quantitative determination..          314
hydrocyanic, detection of, in organicmixtures, &c..                          320
quantitative determination of.                               324
inosic.......              244
lactic....                 227, 244
lithic........       31
meconic.                                                                      325
myristic.......     22
nitric, detection of, in organic mixtures, &c...              315
oxalic.......     317
quantitative determination...     319
phosphoric; detection of...     43, 44, 46
quantitative determination.. 55, 58
prussic......     320
sarcolactic..                                                  244
sulphuric, detection of, in organic mixtures, &c..              311'quantitative determination....      56
in urine..      60
taurocholic......              289
uric.......                31
in the blood......     219
xanthoproteic..                                                 180
Adulterations of milk......     23
Albumen........       80
in urine, estimation of.....      146
tests for......       80
Albuminose........     18t
Albuminous urine......                79




344                                INDEX.
PAOE
Alcohol, detection of, in organic mixtures...    333
Alkaline phosphates, determination in urine... 54, 58
salts of the urine.....              41
Alkapton in urine......      79
Ammonia, detection of, in organic mixtures...    270
determination, in urine.....      53
Ammoniacal salts of the urine.                          41
Amyloid, anial......    241
Animal charcoal, purification of...                     29
Animalcules in the blood.....    223
Anelmia, blood in..                                            212
Annatto in milk...                                237
Antimony, detection of, in organic mixtures...         293
the tissues..            293
determination of.                            294
electrolytic test for...  293
galvanic test for......    293
Reinsch's test for.                            292
Apothecaries' weight.                                            341
Arsenic, detection of, in copper...                     281
hydrochloric acid...             281
organic mixtures...             282
oily or fatty matters..             287
paper hangings...             290
the tissues.....    288
determination of......    290
electrolytic test for......    284
Marsh's test for.    277
reduction test for...                        276
Reinsch's test for......    280
Arsenic acid, separation of.....    289
Arsenious acid...                                           275
Ass, milk of.....      23
Avoirdupois weight......    291
BARnIM, detection of, in organic mixtures..                     337
Becquerel, his analysis of urine...                      63
and Vernois, their analysis of milk.                     230
and Rodier, their analysis of blood.                     209
Benzonitrile.                                                 35
Berzelius, his analysis of bone...    261
urine...            61
Bile, composition of......    289
tests for...                              83
Biliary calculi........    163
matter in the blood.....    222
urine......     83
Bilipheeine......                     241
Biliverdine.                                                    241
Bismuth, detection of, in organic mixture..                     335'Blood                                                                        169
analysis of.......    190
containing animalcules......    223
biliary matter...                 222
excess of albumen..                        214
cholesterin..                    216
corpuscles..            212
fat...                 215
fibrin...                214




INDEX.                                          345
PAGE
Blood, containing excess of saline matter...     210
urea..                                  217
uric acid...                        219
water...                        211
pus.......      222
sugar...      220
corpuscles....                        171
crystals........      177
detected in organic mixtures...     269
on clothing......      175
in  milk..                                                235
in urine..                                                                         82
quantitative analysis of..                                      190
stains of, identified......      175
Bone........               254
dclisease........      262
quantitative analysis of.....      257
Bottger's test for sugar......       76
Bright's disease, urine in......       82
Briicke's process for extracting  sugar..                          78
test for bile.                                             85
Burette........       98
CALCULI, biliary.......     163
cystic.....      158
fusible,.                                                     155
hempseed......      157
incombustible......      161
mulberry.......      156
oxalate of lime......      156
phosphatic.......      153
qualitative examination of...                         159
triple phosphate......      154
urate of ammonia.....               153
uric acid.......      151
urinary.......      150
Calomel, detection of, in organic mixtures, &c...               295
Carbonic acid, estimation  of......     260
Cartilage........     254
Casein........     225
Casts, fibrinous........       82
Chalkstones........     164
Charcoal, animal, purification of...                 29
Chlorine, determination of, in urine.....  55,60
Chlorosis, blood in.......     212
Cholepyrrhin........     222
Cholera, blood in.......     212
Cholesterin........     163
in the blood                                                                  216
Choline........      239
Chondrin........     266
Chylous urine........      87
Collin.......               266
Colostrum                                                                                   228
Combustible calculi, examination of...                  160, 162
Concretions, gouty......     164
Conia, detection of, in  organic mixtures, &c...               338
Copper, detection of, in organic mixtures, &c...               304




346                             INDEX.
PAGE
Copper, electrolytic test for..                                       06
examination of, for arsenic                                    280
quantitative determination of                                  306
standard alkaline solution of                    1...        42
Corpuscles in blood                                                     212
Corrosive sublimate, detection of, in organic mixtures, &c.             294
Cow, milk of                                                            231
Creatine (kreatine).    242
Creatinine (kreatinine)                                                 243
Cystine calculi                                                   1. 58
tests for                                                       121
DEPOSITS, urinary, examination of                                       124
microscopic examination of                          131
Diabetes, blood in                                                      220
Diabetic urine..                                                       71
quantitative analysis of                                  137
Dialysis, separation of poisons by                                      339
Dumas, his analysis of blood                                            209
EARTHY phosphates, determination of, in urine.         53, 59
salts of the urine                                              44
Electrolytic test for antimony......    293
arsenic                                             276
bismuth                                             335
copper                                              306
mercury                                             252
Epithelium                                                               38
Ewe, milk of                                                            231
Excrements, solid..                                           67
Excretine                                                               168
Extractive matters of the blood                                         185
urine.                 39
FAT, detected in organic mixtures                                       269
globules in milk.......    227
Fatty acids, earthy salts of, in urine                    1. 26
volatile, in serum..            186
matters of the blood                                             186
in excess in the blood.                                 215
Feces, constituents of.                                                167
Fermentation test for sugar                                              76
Fibrin.                                          181
excess or deficiency of, in blood                                214
in urine..82
soluble                                                          182
Fibrinous casts..                                              82
Figuier's process for analysis of blood                                 221
Flesh, juice of......    242
Frothing, prevention of......    283
Fusible calculi.                                                       155
GALACTINE                                                               231
Gall-stones                                                             163
Gelatine                                                                254
Globules, organic......            86
Glutin........    255
Glycocine      o. 36, 240




INDEX.                               347
PAGE
Glycogene......                  241
Gum in milk, detection of.                            237
Goat, milk of                                                         231
Gouty concretions                                                      164
HA MATIN      1.....    ] 78
Hoemato-crystalline                                                    179
Haematoidin.                                                       179
Heller's test for bile                                                  84
eIempseed calculi.......    157
Hepatine                                                               201
Hippuric acid                                                           33
excess of, in urine                                        67
Hydrochloric acid, detection of, in organic mixtures.            313
quantitative determination of                       314
Hydrocyanic acid, detection of, in organic mixtures, &c...    320
Henry and Humbert's test for                        322
Liebig's test for                                   321
quantitative determination of                       324
Scheele's test for                                  321
sulphur test for                                    322
Hypoxanthine.                                                         244
IMIPERIAL measure.                                     341
Incineration of organic matter.....     52
Indigo extracted from urine....                    40
Inosite........            244
detection of, in organic mixtures                               268
Iodide of potassium, detection of, in organic mixtures.            310
Iodine, detection of, in organic mixtures...            309
in the urine                                       92
JUICE of flesh.                                                   242
IKIESTEIN........     87
K(reatine.......            242
detection of, in organic mixtures                             268
IKreatinine........   243
determination of, in urine.                                 37
LACTIC acid..227, 244
Lactine.........   226
Lactometer..   238
Lead detected in water                                                 299
detected in the tissues                                          303
search for, in organic mixtures.                                300
Lecithine........   239
Leucine                                                                273
Liebig's process for estimating urea..                   96
Liquor sanguinis....                          171
Liver, saccharine matter from.                                       241
Lithate of ammonia..... 32, 65
lithia......                33
potash..                                         32
soda..                  -         32
Lithic acid            ~.'.       31
detected in organic mixtures..             271
excess of in urine.                                        64




343                            INDEX.
PAGE
MARGARINE.                             228
Marsh's test for arsenic...   277
Maumen6's test for sugar...                                 75
Meconic acid.,                   325
Mercury, detection of, in organic mixtures                            295
electrolytic test for.                         297
galvanic test for..   297
Lassaigne's test for.                                      296
nitrate, preparation of..                   97
Microscopic examination of urinary deposits..        131
Milk.                                224
adulteration of...                  236
containing blood.                                               235
pus...           235
detected in organic mixtures...           269
globules.                                 227
human composition of.                      229
morbid.                                 234
quantitative analysis of......    232
sugar of.                                 226
valuation of....   237
Milky blood                                                           216
Villon's test for albumen...                          81
Mixed animal fluids, examination of..                      272
Moore's test for sugar.....     75
Morbid blood.                                        210
bone.                                262
milk.                                234
mucus......   248
urine..                                 63
Morbid urine, qualitative examination of..                   94
Morphia, detection of.                                               326
M~iucus.                                                245
morbid.                                248
quantitative analysis of.                  247
NICOTIA, detection of, in organic mixtures..                  330
Nitrate of urea.                                                30
Nitric acid, detection of, in organic mixtures.               315
in stains on clothing.         317
Nux vomica                                                            328
OLEINE..                                        228
Opium, detection of, in organic mixtures..           325
Organic globules in urine.                       86
Osseine.                                                             254
Oxalate of lime calculi.                      156
deposits.....            89
of urea                                                        29
Oxalic acid, detection of, in organic mixtures.                   317
quantitative determination of..              319
PALMITINE.                                                        228
Paper-hangings, detection of arsenic in                               290
Parchment paper..                                       284
Peptone.....                                181
Pettenkofer's test for bile.                                         83
Phosphate of ammonia and magnesia calculi..               154




INDEX.                                     349
PAGE
Phosphate of lime calculi..                                   153
crystals, in urine...                       70
Phosphates, determination of, in urine..                       58
Phosphoric acid, genemial process for determining.                      259
Phosphorous acid, detection of, in organic mixtures.    332
Phosphorus........    331
Pipette.                                                                          98
Poisons, detection of, in organic mixtures, &c....           274
separation of, by dialysis...                      339
Protein.........    181
Prussic acid, detection of, in organic mixtures.    320
quantitative determination of.....    324
Scheele's test for.                                               321
sulphur test for.                          322
Purpurine.....69
Pus........    249
blue........    252
in blood........    222
in milk........    235
in urine....      85
quantitative analysis of......    252
Pyin.........    250
Pyocyanine......    252
REDUCTION test for arsenic......    276
Reinsch's test for antimony...                          292
arsenic.                         280
SARCINc........    243
Sarcolactic acid.                               244
Sarcosine........    243
Scheele's green......    276
Semen.                                                                            88
Serolin.        -....    186
Serum, composition of......    209
Silver, detection of, in organic mixtures...             336
Specific gravity of urine taken.....    123
Spermatozoa.......      88
Stains of blood identified....    175
Starch-granules.......    237
Stearine...                                               269
Strychnia, detection of, in organic mixtures...              328
identification of.....    328
Sugar, Bittger's test for......      76
detected in organic mixtures.                                           270
diabetic.                                                                 71
fermentation test for.....              76
in blood.......    220
in healthy urine......      39
in urine, estimation of..     142
Maauimene's test for......      75
Moore's test for......      75
of flesh (inosite)......    244
of liver........    241
of milk.                                                                 226
determination of.....    23
tests for........      71
Trommer's test for......      73
30




350                           INDEX.
PA(R
Sugar, volumetric determination of                                  142
Sulphate of indigo, detection of, in organic mixtures               312
Sulphuric acid, detection of, in organic mixtures                   311
in stains on clothing                    312
Syntonin                                                            184
System for analysis of animal substances                            272
detection of poisons                                      333
TAURINE                                                             240
Tobacco, detection of.                                             330
Torula.                                                            77
Triple-phosphate calculi                                            154
deposits...45, 70
Trommer's test for sugar                                              73
Troy weight....   341
Tyrosine in urine                                                   122
URATs of ammonia                                                      32
calculi                                           153
deposits                                           65
lime in calculi.                                158
lithia                                                     32
potash                                                     32
soda.                      32, 66
in the blood                                          219
Urea                                                                 27
detected in organic mixtures                                    267
excess of, in urine                                              64
in the blood                                                    217
method of estimating                                             48
Davy's                                      102
Leconte's                                    100
Liebig's                                     96
nitrate of.    30
oxalate of.    29
Uric acid                                                            31
calculi of                                                 151
deposits                                                   103
detected in organic mixtures                               271
excess of, in urine                                         65
in the blood.   219
Uric oxide                                                          152
Urina chyli                                                          25
potus                                                           25
sanguinis                                                      25
Urinary calculi.....  150
deposits, examination of                                    124
microscopic examination of                         131
Urine, albuminous, quantitative analysis of.   146
chylous.                                                      87
coloring matter of                                             40
containing albumen                                             79
alkapton..... -  79
bile.    83
blood...                   82
cystine.                                      121
fat                                                  87
iodine, &c.                                          93




INDEX.                                     351
PAGvE
Urine containing oxalate of lime.....      89
pus......               85
semen.....              88
urate of soda.....      66
determination of acidity of.....      60
diabetic.                                        71
quantitative analysis of....    137
healthy.......      25
average composition of....      61
quantitative analysis of....      48
specific gravity of.....        26, 123
morbid........      63
qualitative examination of....      94
with excess of alkaline salts....        69, 111
earthy phosphates...        69, 111.
extractive matters...        68, 109
hippuric acid..                 67, 107
mucus...        67, 108
urate of ammonia..                 65, 104
urea.....          64, 95
uric acid...             64, 103
Urinometer......                     123
Uroglaucine........      41
Urohaematin.......     40
Urostealith........    161
Uroxanthin........      41
Urrhodin........     41
VENOUS blood, composition of...                     209
Vesical mucus.                                                                    38
WATER, detection of lead in......    299
Weights and measures.......    341
XANTHIC oxide...                                      152
ZINC, detection of, in organic mixtures....    307








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&IPBELL'S LIVES OF LORDS KENYON, ELLENBOROUGH, AND
TENTERDEN. Being the third volume of " Campbell's Lives of
the Chief Justices of England." In one crown octavo vol., cloth, $2.
DALTON (J. c.) ATREATISE ON HUMAN PHYSIOLOGY. Fifth
edition, thoroughly revised, with nearly 300 illustrations on wood.
In one very handsome octavo vol. of over 700 pages.  (Now ready.)
Extra cloth, $5 25; leather, $6 25.
T   J30NGH, ON THE THREE KINDS OF COD-LIVER OIL. 1 small
D l12mo. vol., 75 cents.




4              HENRY C. LEA'S PUBLICATIONS.
DON QUIXOTE DE LA MANCHA. Translated by Chas. Jarvis, Esq.,
with illustrations by Tony Johannot.  In two handsome vols. crown
8vo., fancy cloth, $3; plain cloth, $2 50; library sheep, $3 20;
half morocco, $3 70.
EWEES (W. P.)  A TREATISE ON THE DISEASES OF FEMALES.
D With illustrations. In one 8vo. vol. of 536 pages, extra cloth, $3.
-      A COMPREHENSIVE  SYSTEM  OF MIDWIFERY.  In one
octavo volume of 600 pages, with plates, extra cloth, $3 50.
-------  A TREATISE ON THE PHYSICAL AND MEDICAL TREATMENT OF CHILDREN. In one octavo volume of 548 pages, extra
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TfRUITT (ROBERT). THE PRINCIPLES AND PRACTICE OF MOD   DERN SURGERY. A revised American, from the eighth London
edition. Illustrated with 432 wood engravings. In one handsome
8vo. vol. of nearly 700 large and closely printed pages, extra
cloth, $4; leather, $5.
D UNGLISON  (ROEBLEY). MEDICAL LEXICON; a Dictionary of
J   Medical Science. Containing a concise explanation of the various
subjects and terms of Anatomy, Physiology, Pathology, Hygiene,
Therapeutics, Pharmacology, Pharmacy, Surgery, Obstetrics, Medical
Jurisprudence, and Dentistry. Notices of Climate and of Mineral
Waters; Formule for Officinal, Empirical, and Dietetic Preparations,
with the accentuation and Etymology of the Terms, and the French
and other Synonymes; so as to constitute a French as well as English
Medical Lexicon. In one very large royal 8vo. vol. of 1048 double
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------ IHUMAN PHYSIOLOGY. Eighth edition, thoroughly revised.
In two large 8vo. vols. of about 1500 pages, with 532 illustrations,
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-  NEW REMEDIES, WITH FORMULA FOR THEIR PREPARATION AND ADMINISTRATION. Seventh edition. In one very
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JE LA BECHE'S GEOLOGICAL OBSERVER. In-one large 8vo. vol.
of 700 pages, with 300 illustrations, cloth, $4.
ANA (TAES DB.) THE STRUCTURE AND CLASSIFICATION OF
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ELLIS (BENJAMIN).  THE  MEDICAL  FORMULARY.  Being a
collection of prescriptions derived from the writings and practice of
the most eminent physicians of America and Europe. Twelfth edition, carefully revised by A. H. Smith, M. D. In one 8vo. volume
of 374 pages, extra cloth, $3.
ERICHSEN  (JOHN). THE  SCIENCE AND  ART OF SURGERY.
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-    ON RAILWAY AND OTHER INJURIES OF THE NERVOUS
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ENCYCLOPIEDIA  AMERICANA. Complete in 14 large 8vo. vols.
Coitaining nearly 9000 double columned pages, cloth, $22.
ENCYCLOPIEDIA OF GEOGRAPHY. In three large 8vo. vols. Illustrated with 83 maps and about 1100 wood-cuts, cloth, $5.




HENRY C. LEA'S PUBLICATIONS.                      5
F  SKE FUND PRIZE ESSAYS ON TUBERCULOUS DISEASE. In
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FLETCHER'S NOTES FROM NINEVEH, AND TRAVELS IN MESOPOTAMIA, ASSYRIA, AND SYRIA. In one 12mo. vol., cloth, 75 cts.
FLINT  (aUSTIN). A  TREATISE  ON THE PRINCIPLES AND
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leather, raised bands, $7.
A PRACTICAL TREATISE, ON THE PHYSICAL EXPLORATION OF THE CHEST, AND THE DIAGNOSIS OF DISEASES
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A PRACTICAL TREATISE ON THE DIAGNOSIS AND TREATMENT OF DISEASES OF THE HEART. Second edition, enlarged.
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oWNE (GEORGE). A MANUAL OF ELEMENTARY CHEMISTRY.
From the tenth enlarged English edition. In one royal 12mo. vol. of
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FULLEtR (HENRY). ON DISEASES OF THE LUNGS AND AIR
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(JLUGE (GOTTLIEB). ATLAS OF PATHOLOGICAL HISTOLOGY.
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G IBSON'S INSTITUTES AND PRACTICE OF SURGERY. In two 8vo.
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GUFRSANT (P,) SURGICAL DISEASES OF INFANTS AND CHIL.
DREN. Translated by R. J. Dunglison, M. D. (Pktblishiszg iu the
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issuzed. )




6   HENHENRY  C. LEA'S PUBLICATIONS.
ARTSHORNE (HENRY). ESSENTIALS OF THE PRINCIPLES
H AND PRACTICE OF MEDICINE. Third and revised edition. In
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- CONSPECTUS OF THE MEDICAL SCIENCES.  Comprising
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_ARRISON'S ESSAY  TOWARD A CORRECT THEORY OF THE.    NERVOUS SYSTEM. In one vol. 8vo. of 292 pages, cloth, $1 50.
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O        0DGE (YUGH L.) ON DISEASES PECULIAR TO WOMEN, IN1 CLUTDING DISPLACEMENTS OF THE UTERUS. Second and
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----   THE PRINCIPLES AND PRACTICE OF OBSTETRICS. Illustrated with large lithographic plates containing 159 figures from
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1OLLAND (SIR HENRY). MEDICAL NOTES AND REFLECTIONS.
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ODGES (RICHARD M.) PRACTICAL DISSECTIONS. Second edition. In one neat royal 12mo. vol., half bound, $2.
HUGHES' SCRIPTURE  GEOGRAPHY  AND  HISTORY, with 12
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HRONER (WILLIAM E.). SPECIAL ANATOMY AND HISTOLOGY.
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HILL (BERKELEY). SYPHILIS AND LOCAL CONTAGIOUS DISORDERS. In one 8vo. volume of 467 pages, extra cloth, $3 25.
ILLIER (THOMAS). HAND-BOOK OF SKIN DISEASES. Second
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JONES (0. HANDFIELD). CLINICAL OBSERVATIONS ON FUNCTIONAL NERVOUS DISORDERS. Second American Edition. In
one 8vo. vol. of 348 pages, extra cloth, $3 25.




HENRY C. LEA'S PUBLICATIONS.                     7
KIRKES (WILLIAM SENHOUSE). A MANUAL OF PHYSIOLOGY.
From the third London edition, with 200 illustrations. In one large
12mo. vol. of 586 pages, cloth, $2 25; leather, $2 75.
KTNAPP (F.) TECHNOLOGY; OR CHEMISTRY APPLIED TO THE
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cloth, $6.
KENNEDY'S MEMOIRS OF THE LIFE OF WILLIAM WIRT. In
two vols. 12mo., cloth, $2.
EA (HENRY C.) SUPERSTITION AND FORCE; ESSAYS ON THE
WAGER OF LAW, THE WAGER OF BATTLE, THE ORDEAL,
AND TORTURE. Second edition, revised. In one handsome royal
12mo. vol., $2 75. (Lately issued.)
STUDIES IN CHURCH HISTORY. The Rise of the Temporal
Power-Benefit of Clergy-Excommunication.  In one handsome
1211o. vol. 6f 515 pp., extra cloth, $2 75. (Lately issued.)
LALLEIAND  (M.) AND  WILSON  (MARRIS).  A  PRACTICAL
L   TREATISE ON THE CAUSES, SYMPTOMS, AND TREATMENT
OF SPERMATORRH(EA.  Translated and edited by Henry J.
McDougall. Fifth American edition. To which is added -- ON
DISEASES OF THE VESICULE SEMINALES. With special reference to the Morbid Secretions of the Prostatic and Urethral
Mucous Membrane. By Marris Wilson. M. D. In one neat octavo
volume, of about 400 pages, extra cloth, $2 75.
L A ROCHE (R.) YELLOW FEVER IN ITS HISTORICAL, PATHOLOGICAL, ETIOLOGICAL, AND  THERAPEUTICAL  RELATIONS. In two 8vo. vols. of nearly 1500 pages, extra cloth, $7.
----  PNEUMONIA, ITS SUPPOSED  CONNECTION, PATHOLOGICAL AND ETIOLOGICAL, WITH AUTUMNAL FEVERS. In
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LAURENCE (J. Z.) AND MOON (ROBERT C.)  A HANDY-BOOK
L   OF OPHTHALMIC SURGERY.  Second edition, revised by Mr.
Laurence. With numerous illustrations. In one 8vo. vol., extra
cloth, $2 75.
TEHMIANN (C. G.) PHYSIOLOGICAL CHEMISTRY. Translated by
George P. Day, M. D., and edited by R. E. Rogers, M. D., Prof. of
Chemistry, in the University of Pennsylvania. With plates, and nearly
200 illustrations. In two large 8vo. vols., containing 1200 pages,
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--  A MANUAL OF CHEMICAL PHYSIOLOGY. Translated with
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LAWSON (GEORGE). INJURIES OF THE EYE, ORBIT, AND EYEL   LIDS, with about 100 illustrations. From the last English edition.
In one handsome 8vo. vol., extra cloth, $3 50.
LUDLOW  (J. L.) A MANUAL OF EXAMINATIONS UPON ANAL   TOMY, PHYSIOLOGY, SURGERY, PRACTICE OF MEDICINE,
OBSTETRICS, MATERIA MEDICA, CHEMISTRY, PHARMACY,
AND THERAPEUTICS. To which is added a Medical Formulary.
Third edition. In one royal 12mo. vol. of over 800 pages, extra
cloth, $3 25; leather, $3 75.
LAYCOCK (THOMAS). LECTURES ON TI-IE PRINCIPLES AND
METHODS OF MEDICAL OBSERVATION AND RESEARCH, In
one 12mo. vol., extra cloth, $1.




8             HENRY C. LEA'S PUBLICATIONS.
YNCH (W. F.) A NARRATIVE OF THE UNITED STATES EXPEDITION TO THE DEAD SEA AND RIVER JORDAN. In one
large and handsome octavo vol., with 28 beautiful plates and two
maps, cloth, $3.
-     Same Work, condensed edition. One volume royal 12mo., extra
cloth, $1.
YONES (ROBERT D.) A TREATISE ON FEVER. In one neat 8vo.
vol. of 362 pages, extra cloth, $2 25.
MARSHALL  (JOHN).  OUTLINES  OF PHYSIOLOGY, HUMAN
AND COMPARATIVE. With Additions by FRANCIS G. SMITH,
M. D., Professor of the Institutes of Medicine in the University of
Pennsylvania. In one 8vo. volume of 1026 pages, with 122 illustrations. Strongly bound in leather, raised bands, $7 50; extra cloth,
$6 50.
M~ACLISE (JOSEPH). SURGICAL ANATOMY. In one large imMLY perial quarto vol., with 68 splendid plates, beautifully colored; con.
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MEIGS (CHAS. D.) OBSTETRICS, THE SCIENCE AND THE ART.
ML. Fifth edition, revised, with 130 illustrations. In one beautifully
printed 8vo. vol. of 760 pages, extra cloth, $5 50; leather, $6 50.
--  -WOMAN: tIER DISEASES AND THEIR REMEDIES. Fourth
and improved edition. In one large 8vo. vol. of over 700 pages,
extra cloth, $5; leather, $6.
-   ON THE NATURE, SIGN S, AND TREATMENT OF CHILD-BED
FEVER. In one 8vo. vol. of 365 pages, extra cloth, $2.
M:ILLER (JAMES). PRINCIPLES OF SURGERY. Fourth American,
from the third Edinburgh edition.  In one large 8vo. vol. of 700
pagnes, with 240 illustrations, extra cloth, $3 75.
— T —THE  PRACTICE OF SURGERY. Fourth American, from the
last Edinburgh edition. In one large 8vo. vol. of 700 pages, with
364 illustrations, extra cloth, $3 75.
/OiNTGOXMERY (W. F.)  AN EXPOSITION OF THE SIGNS AND
l   SYMPTOMS OF PREGNANCY. From the second English edition.
In one handsome 8vo. vol. of nearly 600 pages, extra cloth, $3 75.
O3RLAND (W. W.) DISEASES OF THE URINARY ORGANS. With
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ORL&ND (W. W.) ON THE RETENTION IN THE BLOOD OF THE
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MULLER (J.) PRINCIPLES OF PHYSICS AND METEOROLOGY.
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iTR&BEAU; A LIFE HISTORY. In one royal 12mo. vol., cloth,
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A/f&CFARLAND'S TURKEY AND ITS DESTINY. In 2 vols. royal
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M XRSHI (MRS.) A HISTORY OF THE PROTESTANT REFORMATION IN FRANCE. In 2 vols. royal 12mo., extra cloth, $2.
EILL (JOHN) AND SMITH  (FRANCIS G.) COMPENDIUM  OF
aN THE VARIOUS BRANCHES OF MEDICAL SCIENCE. In One
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extra cloth, $4; leather, raised bands, $4 75.




HENRY C. LEA'S PUBLICATIONS.                      9
NTEI, YAN (J. MOR001EE). A PRACTICAL TREATISE ON DISEASES.   OF THE SKIN. Fifth American, from the second Dublin edition.
In one neat royal 12mo. vol. of 462 pages, extra cloth, $2 25.
AN ATLAS OF CUTANEOUS DISEASES. In one handsome
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TIEBTUH-R (B. G.) LECTURES ON ANCIENT HISTORY; coml   prising  the  history  of the  Asiatic  Nations, the  Egyptians,
Greeks, Macedonians, and Carthagenians. Translated by Dr. L.
Schmitz. In three neat volumes, crown octavo, cloth, $5 00.
L tING (WILLIAXiE). A COURSE OF PRACTICAL CHEMISTRY
V FOR THE USE OF MEDICAL STUDENTS. From the fourth
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fAVY IF. W,) A TREATISE ON THE FUNCTION OF DIGESTION:
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PARRISH (EDWARD). A TREATISE ON PHARMACY. With many
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PIRRIET (WILLI.AM)  THE PRINCIPLES AND PRACTICE OF.SUR1  GERY. In one handsome octavo volume of 780 pages, with 316
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TERi RA (JONQATHAN). MATERIA MEDICA AND THERAPEUTICS. An abridged edition. With numerous additions and references to the United States Pharmacopoeia.  By Horatio C. Wood,
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OBER.TS (WILLIMA). A PRACTICAL TREATISE ON URINARY
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RA.SBOTfHATi       (FRANCIS H,) THE PRINCIPLES AND  PRACTICE OF OBSTETRIC MEDICINE AND SURGERY. In one imperial 8vo. vol. of 650 pages, with 64 plates, besides numerous woodcuts in the text. Strongly bound in leather $7.
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$2 50.
ANEE'S HISTORY OF THE TURKISH AND SPANISH EMPIRES
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AD:ICtFFE, AINSTIE, AND OTHERS, ON DISEASES OF THE
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10  HENRY C. LEA'S PUBLICATIONS.
SITH-i (EUSrACE). ON THE WASTING DISEASES OF CHILDREN.
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$2 50. (Joust issuerd.)
SARGEIT (7. W.) ON BANDAGING AND OTHER OPERATIONS
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51UTH (I. LEWI ) A TREATISE ON THE DISEASES OF INA  FANCY AND CHILDHOOD. Second edition.  (lVeari/y ready.)  In
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6AP,.pEY  (W!IAJT.X  ) AANTD  QAAIN  (1ONES AND  7,iCHA RD).
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Mt{PS0N' (31IR JiAIES Y.)  CLINICAL LECTURES ON THE DISEASES OF WOMEN. (A new edition preparing.)
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SLADE (D. D.) DIPHTHERIA; ITS NATURE AND TREATMENT.
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T.ILLE (ALFRED). THERAPEUTICS AND MATERIA  MEDICA.
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— MEMOIRS OF ELIZABETH, SECOND QUEEN REGNANT OF
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HENRY C. LEA'S PUBLICATIONS.                     11
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--  ON THIE SIGNS AND DISEASES OF PREGNANCY. First
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