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"This is a beautiful little book beautiful in its printing, its colored plates, and its whole getting up, and is well adapted to instruct and amuse those for whom it is intended. There are twelve plates, containing numerous figures, drawn with much care, even to minute details. The spirit of the work is excellent, and we wish it in the hands of all the children of the land." Silliman's Journal. "It communicates substantial knowledge in the most entertaining way, and opens to the young intellect the whole subject of natural philosophy. The colored en- gravings greatly illustrate these instructions. We have seen no book written for young people that we can more cordially recommend." Christian Advocate and Journal. "The revelations of the microscope are truly astonishing; and the effort to unveil the minute parts of creation visible to youthful eyes by its amazing power, is worthy of praise. The style of this volume is adapted to the class for which it is prepared! and the numerous illustrations, beautifully colored, not only add to its beauty, but also to its usefulness." Recorder. "The style of the book is simple, yet comprehensive; and there are few men and women who will not, as well as the young, find pleasure and instruction in its pages. The colored plates, showing the appearance of a variety of things, animate and in- animate, as they appear when subjected to the microscope, are well executed, and form not the least attractive feature in the volume." Home Gazette. "For children who have any germs of a taste for scientific investigations, this little book would be highly attractive, and would encourage in all whom curiosity might tempt to its perusal, that love of Nature which forms one of the purest and richest sources of pleasure through life." Saturday Post. " No more beautiful present can be given to our children, nor one better calculated to enlarge their views of the wonders of creation. It will also furnish much knowledge to children of a larger growth." State Banner. LINDSAY & BLAKISTON, Publishers. PLATE. 2. T. Sindairs OR, THE MICROSCOPIST; 3Jtattttfll USE OF THE MICROSCOPE FOR PHYSICIANS, STUDENTS, AND ALL LOVERS OF NATURAL SCIENCE. SECOND EDITION, IMPROVED AND ENLARGED. WITH ILLUSTRATIONS. BY JOSEPH H. WITHES, M.D. PHILADELPHIA: LINDSAY AND BLAKISTON. LONDON: TRUBNER & C0. 1853. Entered, according to Act of Congress, in the year 1853, BY LINDSAY AND BLAKISTON, In the Clerk's Office of the District Court for the Eastern District of 1'ennsylvania. C. SHERMAN, PRINTER. TO PAUL BECK GODDARD, MJD., DISTINGUISHED BY HIS ARDENT AND SUCCESSFUL PROSECUTION OP THIS AND KINDRED STUDIES, IS RESPECTFULLY INSCRIBED BY THE AUTHOR. M354533 PREFACE TO THE SECOND EDITION. THE rapid sale of the first edition of this work, both in England and the United States, proves its adaptation to the wants of the scientific community, and justifies the care and extra expense with which this second edition has been prepared. Although the first edition was unusually large, it is not at all probable that the demand has been exhausted. But a little more than a year has elapsed since its appearance, yet sufficient time has been afforded for the author to make a number of important additions, which increase the value of the work to the student of nature. The facts relating to microscopic science are not the result of one man's labors, or of a single generation, but have been gradually accumulating for many years ; yet at the present the number of indefatigable observers is very considerable, and the author is presumptuous enough to think that the preparation of this manual has increased that number, by diminishing the difficulty of the study, and pointing out the most judicious methods of observation. V1H PREFACE. For the flattering notice taken of this work by the medical and scientific journals, the author is under many obligations, many prominent periodicals having spoken of it in terms of the highest praise. It has formed no part of the design of this book to describe the mechanical arrangements of different instrument-makers; yet sufficient directions have been given to enable any one pos- sessed of a microscope, of any mechanical form and arrange- ment, to use it to the best advantage. , Whatever be the favorite pursuit of the student, whether Botany, Zoology, Anatomy, Physiology, or Pathology, the present manual gives information, by means of which the microscope may be profit- ably employed. In addition to this, the chapters on Minute Dissection, Injection, &c., will be of interest to many. CONTENTS. CHAPTER I. THK HISTORY AND IMPORTANCE or MICROSCOPIC IN- VESTIGATION, .... .- 13 II. THE MICROSCOPE, .... 22 III. ADJUNCTS TO THE MICROSCOPE, . . .41 IV. How TO USE THE MICROSCOPE, . . 51 V. ON MOUNTING AND PRESERVING OBJECTS FOR EXA- MINATION, . . . . .55 VI. ON PROCURING OBJECTS FOR THE MICROSCOPE, 67 VII. TEST OBJECTS, . . . . .110 VIII. ON DISSECTING OBJECTS FOR THE MICROSCOPE, 118 IX. THE CELL-DOCTRINE OF PHYSIOLOGY, . . 129 X. EXAMINATION OF MORBID STRUCTURES, ETC., 139 XI. ON MINUTE INJECTIONS, . . . 158 XII. EXAMINATION OF URINARY DEPOSITS, . .169 XIII. ON POLARIZED LIGHT, . . . . 188 XIV. MISCELLANEOUS HINTS TO MICROSCOPISTS, . 196 THE MICEOSCOPIST. CHAPTER I. THE HISTORY AND IMPORTANCE OP MICROSCOPIC INVESTIGATION. FROM the earliest period of scientific research, the magnify- ing properties of lenses have been used to penetrate the arcana of nature, and with most striking results. A vast amount of information, which could have been obtained in no other way, has been added, by microscopic observation, to almost every branch of natural science. To the Christian philosopher, the microscope reveals the most amazing evidence of that Creative Power and Wisdom before which great and small are terms without meaning. He rises from the contemplation of the minutise which it displays, feeling more strongly than ever the force of those beautiful words " If God so clothe the grass of the field, which to-day is, and to-morrow is cast into the oven, shall he not much more clothe you ? ye of little faith !" To the geologist, it reveals the striking, yet humbling fact, that the world on which we tread is but the wreck of ancient 14 THE MICROSCOPIST. organic creations. The large coal beds are the ruins of a luxuriant and gigantic vegetation; and the vast limestone rocks, which are so abundant on the earth's surface, are the catacombs of myriads of animal tribes which are too minute to be perceived by the unassisted vision. It exhibits, also, that metallic ore, as the Bog Iron Ore, and immense layers of earthy and rocky matter, are formed merely by the aggregation of the skeletons or shields of Infusoria ; while beds of coral rocks are still in the process of formation, the architects being tiny marine polypi. Further, by this instrument, the nature of gigantic fossil remains is often determined, and by it they are assigned their true place in the classification of the naturalist. To the student of vegetable physiology, the microscope is an indispensable instrument. By it he is enabled to trace the first beginnings of vegetable life, and the function of the dif- ferent tissues and vessels in plants. The zoologist finds it also a necessary auxiliary. Without it, not only would the structure and functions of many animals remain unknown, but the existence of numerous species would be undiscovered. It is to the medical student and practitioner, however, that the microscope especially commends itself for its utility. A new branch of medical study histology has been created by its means alone ; while its contributions to morbid anatomy and physiology, or pathology, are indispensable to the student or physician who would excel, or even keep pace with the progress of others, in his profession. To such the following remarks will doubtless be interesting. Histology is that science which treats of the minute or ulti- mate structure and composition of the different textures of organized bodies. It is derived from itfros, a tissue or web, and Xoyoc:, a discourse. HISTORICAL INVESTIGATION. 15 The attempts made by the early microscopic observers to de- termine ultimate structure, were in general of little value, partly on account of the imperfections in the instruments em- ployed, and partly from the mistakes they made in judging of the novel appearances presented to their view. This last cause of error still exists, and inexperienced observers may very readily be led astray. By such, a fibre of cotton upon the stage of the microscope, moving in obedience to the hygrometric influence of the breath or of a moist atmosphere, might be re- garded as a living animal ; or the influence of various reagents on pus, mucus, blood, or other matters, might lead to error. This last was the case with the celebrated Borelli, who was the first to apply the microscope to the examination of struc- ture. Borelli was born in 1608, and lectured as professor in the University of Pisa in 1656. In his day a general idea pre- vailed, that diseases were occasioned by animalculse existing in the animal tissues and fluids. An examination of abnormal fluids with the microscope favored this idea, as the globules were immediately taken for living beings. Borelli described the pus globules as animalcules, and even says he has seen them delivering their eggs. It will be seen that this was a very natural mistake, when we remember that these globules contain several minute granules, which make their escape when the external envelope is broken or dissolved. In this way we often find the germs of truth in the curious speculations of the early microscopists. Malpighi was the first to witness the most beautiful sight which the microscope can reveal, the actual circulation of the blood, thereby demonstrating the reasoning of Harvey to be true. The first work he published, in 1661, comprises his microscopic observations relative to the structure of the lungs. Between this period and 1665, he published other tracts on the 16 THE MICROSCOPIST. minute anatomy of the kidneys, spleen, liver, membranes of the brain, &c., and several of the structures still retain his name. He also paid attention to the anatomy and transformations of insects, the development of the chick in the egg, and the struc- ture of plants. It will be perceived from the last remark, that the intimate connexion between animal and vegetable physiology was even then acknowledged. This connexion has led to the establishment of the cell doctrine, or the theory of the develop- ment of all organized tissues from cells. Lewenhoeck has sometimes been called the father of micro- graphy. He was born at Delft, in Holland, in 1663, and appears to have received a rather indifferent early education. He first brought himself into notice by the skill with which he ground glasses for microscopes and spectacles, and for improve- ments in those instruments ; thus affording a good model for microscopic observers : first attending to the optical and mechanical construction of the instrument he was to employ. In 1690 he discovered and demonstrated the capillary blood- vessels. He opposed the chemical doctrines which then reigned in medicine, which attributed disease to fermentation in the blood. He objected ; that if fermentation existed, air bubbles would be seen in the vessels, which was not the case. He showed that the blood-globules were of different sizes and forms in various tribes of animals ; examined the brain and nerves, the muscles, the crystalline lens, the milk, and numerous other textures and fluids ; and made the interesting discovery of the spermatozoa, which he conceived to be of different sexes. There can be no doubt that he made numerous errors, but the whole subject being new, his errors were excusable; and his contribu- tions to science are still of the highest interest. Swammerdarn, Lyonet, and Ellis, after this period, greatly extended our knowledge of the lower tribes of animals; while HISTORICAL INVESTIGATION. 17 Lieberkuhn, Fontana, and Hewson labored successfully in the department of histology. To Lieberkuhn we owe the first good account of the anatomy of the villi, and of the minute tubular glands of the small intestine, which still bear his name. As a minute injector he has never been surpassed. Fontana examined the brain, nerves, muscles, and several other textures, with great care, and his observations were ex- tremely accurate. Hewson is celebrated for his accurate observations on the blood and lymph corpuscles. He first demonstrated that the blood-globules were flat, with a central nucleus, and not round, as had been previously supposed. < -' Nearly all the celebrated men alluded to, made use of the simple microscope. At this period the compound microscope was very defective. It was more of a toy than a scientific instrument. From an ignorance of many phenomena connected with the microscope which are now well understood, many errors re- sulted. Optical illusions were mistaken for natural appear- ances, as was the case with Monro. In his discoveries respect- ing the brain and nerves, he describes them as being formed of convoluted fibres, and in his examination of other textures he saw the same fibres and always mistook them for nerves. The fact was, that he made his observations while the direct rays of the sun were transmitted through the substance under examination, and the optical phenomena which were produced led to the mistake. He afterwards found them on the surface of metals, and then frankly acknowledged his error. Another source of early errors was the treatment to which their preparations were subjected before examination. It is now well known that animal tissue should be examined while fresh and transparent. What result is it possible to draw from 2* 18 THE MICROSCOPIST. the observations of those who boil, roast, macerate, putrefy, triturate, and otherwise injure the delicate tissues ? Most of the tissues contain albumen, which, so treated, gives origin to globules, and flakes of different forms ; a circumstance which has led several anatomists to conceive the basis of animal structures to be globular. Several late observers have also made this mistake. Messrs. Todd and Bowman, the learned authors of " The Physiological Anatomy and Physiology of Man," present the following sensible remarks respecting this subject, " To make microscopical observation really beneficial to physiological science, it should be done by those who possess two requisites : an eye, which practice has rendered familiar with genuine appearances as contrasted with those produced by the various aberrations to which the rays of light are liable in their passage through highly refracting media, and which can quickly distinguish the fallacious from the real form; and a mindj capable of detecting sources of fallacy, and of understanding the changes which manipulation, chemical reagents, and other disturbing causes may produce in the arrangement of the ele- mentary parts of various textures. To these we will add another requisite, not more important for microscopical than for other inquiries ; namely, a freedom from preconceived views or notions of particular forms of structure, and an ab- sence of bias in favor of certain theories, or strained analogies. The history of science affords but too many instances of the baneful influence of the idola spectis upon the ablest minds ; and it seems reasonable to expect that such creatures of the fancy would be especially prone to pervert both the bodily and the mental vision, in a kind of observation which is subject to so many causes of error, as that conducted by the aid of the microscope." The invention of the achromatic object-glasses for micro- HISTORICAL INVESTIGATION. 19 scopes formed the beginning of a new epoch in histological pur- suits. Since that period, the confusion and opposition which formerly existed among observers have diminished, and at present only those differences remain which are incident to the pursuit of any other branch of scientific study. In our own times, the Germans seem to have taken the lead in histological observations; and the reputation of the well- known names of Ehrenberg, Miiller, Schwann, Schulz, Wagner, Weber, and Valentin, principally depends on the discoveries they have made by means of the microscope. In England, the names of Carpenter, Todd, Bowman, Owen, Cooper, Busk, Quekett, Bowerbank, and others, are connected with microscopic research. In our own country, a spirit of emulation seems excited which promises great advantage. Professor Bailey of West Point, and our townsmen, Drs. Leidy and Goddard, may be mentioned among others who have contributed to this result. The recent lectures of Dr. Goadby (late minute dissector to the Royal College of Surgeons, England), on microscopic science have done much to increase a desire on the part of medical students and others to become practically acquainted with this subject. His lectures to the students of the Phila- delphia College of Medicine, and at other places, were well attended ; as likewise were his private classes. Of his valu- able suggestions I have frequently availed myself. The advantage of a practical acquaintance with the micro- scope by medical men may be easily seen, and is readily acknowledged. Dr. Bennet, of Edinburgh, to whom I am indebted for much of the histological part of this introduction, says " I have lately had many opportunities of satisfying myself that death may be occasioned by structural changes in the brain which are altogether imperceptible to ordinary vision and which have escaped the careful scrutiny of the first morbid 20 THE MICROSCOPIST. anatomists in this city. Again, who would have imagined that porrigo favosa, mentagra, aphtha, and other diseases, consist of cryptogamous plants growing on the skin or mucous mem- branes ? Surely facts like these hold out a strong inducement to the histologist who prosecutes pathological inquiries." In another place he relates the following circumstance, which tends to illustrate the same point : " A gentleman who had an ab- scess in the arm, observed one morning his urine to be turbid, and to deposit a considerable sediment. The practitioner who attended him thought it looked like purulent matter, but before finally forming his diagnosis, he asked me to examine it with the microscope. I did so ; but instead of finding pus corpus- cles, discovered a large quantity of irregularly formed granules, which I recognised to be fibrinous. I immediately suggested that the abscess was on the point of resolution, and I after- wards learned, that from that time it rapidly disappeared. The fact that fibrin exuded into the tissues, and, subsequently absorbed, passes off by the kidneys, was determined by the microscopic observations of Schonlein and Zimmerman in Ger- many/' Many other instances might be adduced, were it necessary, to show the importance of the microscope in diagnosis and in practical medicine. It is not too much to hazard the assertion, that in a few years the practitioner will find it as essential in finding out the nature of disease, and the state of the system, as the most valuable articles of the niateria medica are useful in medical treatment. The following example will illustrate the delicacy as well as utility of this mode of investigation. A few evenings since, while entertaining a friend with some microscopic views, he expressed a wish to see the red globules of the blood ; so, pricking the tip of his finger with a lancet, a drop was extracted, which, after covering with thin glass, was placed upon the stage of the microscope. Observing the glo- HISTORICAL INVESTIGATION. 21 bules, with a greater tendency than usual, to run together into rows, like piles of coin, I remarked to him that his blood assumed an inflammatory or a feverish appearance. He replied, that he had been for about thirty-eight hours without sleep, having sat up with a sick friend the night before, and having some gastric irritation in addition, he had felt feverish all the evening. Observations on pus, mucus, the urine, and the various forms of malignant tumors, &c., all exhibit the value of this instrument to medical science. In medico-legal researches the microscope has already proved a valuable auxiliary. It has several times been employed to ascertain the true nature of spots suspected to be blood-stains, &c. ; and in cases where human life was suspended upon its decision. In 1837, M. Ollivier was directed to ascertain whether any human hair was attached to the blade of a hatchet seized in the house of a person suspected of murder, and if this were the case, to determine the color of the hair. With the micro- scope, M. Ollivier ascertained that the filaments attached to the hatchet were the hairs of an animal, and not of a human being ; and this was afterwards fully proved. CHAPTER II. THE MICROSCOPE. THOSE who have examined a common magnifying glass (or lens) know that it is necessary to hold it exactly at a certain distance from the object viewed through it, in order that such object may be seen with distinctness. The point at which the object must be placed is called the focus of the lens, and the distance from the middle of the lens to the focus is the focal length, or focal distance of the lens. The cut represents sections of the different forms of lenses. A, is a plano-convex lens. B, double convex. C, plano-con- cave. D, double concave. E ; a meniscus. Fig. 1. C The effect of the convex lens or of the meniscus is to cause the rays of light which pass from any object through them, to converge towards a point or focus ; and the eye receiving those THE MICROSCOPE. 23 rays after passing through the lens, sees the object apparently magnified. This principle is the basis upon which all micro- scopes are constructed. The concave lens produces a precisely contrary effect to that described above. The rays of light diverge on passing through it, and the object appears diminished in size. SIMPLE MICROSCOPES. A piano or double convex lens, especially when mounted, or arranged with conveniences for viewing objects, is called a simple microscope. The magnifying power of a simple microscope is in propor- tion to the shortness of its focal length. Thus, a lens of 2 inches focal distance, magnifies 5 diameters (or the superficies 25 times) of 1 inch focus, 10 diameters |ths of an inch, 15 diameters inch, 20 diameters i inch, 40 diameters gth inch, 80 diameters J^th inch, 100 diameters. This table of magnifying powers is not invariably correct, owing to the difference of vision in different individuals, but it is sufficient for all practical purposes. Simple microscopes are mounted in a variety of ways, ac- cording to the purposes for which they are intended. Some are made to turn upon a hinge into a case, so as to carry in the pocket; and others are fixed on a handle, with a pin or small pair of forceps in the focus, on which a small object, as an insect, &c., may be placed. The cut, Fig. 2, exhibits the arrangement of Dr. Withering's Botanical Microscope, which is valuable from its simplicity. It consists of three brass plates, a, I, c, parallel with each other, 24 THEMICROSCOPIST. to the upper and lower of which the stout wires, d, e } are rivet- ted. The middle plate, b, which forms the stage for carrying the objects, is made to slide up and down on these wires. The upper plate, a, carries the lenses, i, and the lower one, c, some- times carries a mirror, for reflecting the light of a candle or of the sky through any transparent object which may be placed on the stage. Into the stage a dissecting knife, h, a pointed Fig. 2. instrument, /, and a pair of forceps, , Fig. 24), or dotted cells (a, Fig. 24); at other times the thickening matter is in the form of a ring or spiral coil, constituting annular (c, Fig. 24) and spiral cells (d, Fig. 24). Vascular Tissue, prepared by maceration and dissection, presents many interesting subjects. Spiral vessels, c, Fig. 23, consist of membranous tubes with conical extremities, inter- nally furnished with one or more spiral fibres. As the vessels grow, the spiral fibre breaks into short pieces, forming rings. The vessels are then called annular, Z>, Fig. 23. If the pieces of fibre are still shorter, they are called dotted or reticulated vessels, c?, Fig. 23. The root of the garden rhubarb, the stem of the hyacinth, the leek, &c., furnish examples. A peculiar form of vessel is met with in the common carrot ; it is obtained from a root in a layer between the yellow central portion ancl the red annulus. Sections of Wood. These are cut thin, so as to allow them to be viewed as transparent objects. Hard woods, containing gum, resin, &c., should be soaked in essential oil, alcohol, ether, &c., before mounting. By transverse slices, a variety of beautiful lace-like objects may be obtained, but little infor- mation is acquired from them of the real structure of the wood. For this purpose, if the tree is of the endogenous and branch- less kind which grow by additions to the interior a vertical section is also necessary. If the tree be an exogen, two verti- cal sections will be required in addition to a transverse one. The exogens grow by annual layers exteriorly under the bark, and are branched. In these one of the vertical sections should be radial and the other tangental. The radial vertical section will show the number and size of the medullary rays ; that is, the small portions of pith which proceed horizontally from the centre, enclosed in a sheath of woody fibres. The frequency and size of the medullary rays determine the number and PROCURING OBJECTS. 73 strength of the branches of the tree. This section also ex- hibits in coniferous trees (as the pine, &c.), the beautiful disc- like glands which adhere to the woody fibres. These are beautiful objects, and sometimes require a power of 200 or 300 diameters. The tangental vertical section is a slice across the medullary rays; it exhibits the form and arrangement of the cellular tissue within them. All the vertical sections show the form, size, and connexion of the woody fibres ; spiral, reticu- lated, and dotted vessels, &c. ; and are far more instructive than the transverse sections. Charcoal. Thin sections of charred wood are very interest- ing and instructive. Fossil Woods. Thin sections must be made by grinding on a lapidary's wheel. They should be polished. Siliceous Cuticles, &c., from equisetum, straw, cane, &c., are prepared by heat in a covered crucible, or by boiling and digestion in nitric acid. The most favorable example for showing the form in which silica occurs in plants, is the husk of the oat or wheat. If a husk of oat be examined under the microscope, having been mounted in water or Canada balsam, a series of bright parallel columns, serrated on each side, may be observed among the cellular tissue : if another specimen be burned carefully between the glasses, and the ashes be mounted in balsam, the siliceous columns will still be seen. In the ashes of the husk of wheat, rows of concave discs may be observed, which are composed of some metallic oxide. In the ashes of the calyx and pollen of the mallow, organized lime may be detected. In the ashes of coal, a variety of vegetable structures, as cellular tissue, spiral vessels, &c., may be dis- covered. In these experiments it is necessary to render the ashes transparent by immersion in balsam. Hairs, Down, &c., from leaves and stems, are generally opaque objects. In the plants which produce cotton, the hairs 7 74 THEMICROSCOPIST. are attached to and envelope the seeds. Hairs are composed of cellular tissue. Their functions are said to be either lym- phatic or secreting. They offer great varieties in form, some being stellated, others forked or branching. The hairs of Vir- ginian spiderwort (Tradescandia Virginica), the sting of the Nettle (Jjrtica dioica), and the radiating scale or hair in Eloeagnus, the Oleaster, are interesting specimens. Pollen may be mounted in Canada balsam; or, if rather transparent, in fluid; or dry. Sometimes the grains are inte- resting opaque objects. The common form of the pollen or farina of flowers is spherical, with a smooth, punctured, or spiny surface; but some are square, others cylindrical, oval with attenuated extremities, or triangular with convex sides. The pollen of the passion flower is very curious, and if immersed in very diluted sulphuric acid opens and disperses the grains. The pollen of Datura stramonium, or Jamestown weed, and others, when immersed in a few drops of weak acid placed upon a slide under the microscope, emits a tube of some length. The granular matter in the pollen may then be seen to pass along the tube until the pollen is emptied. The Diameter of the pollen varies considerably in different plants; among the smallest are those of the Sensitive Plant. Starch. The granules of starch (not the ordinary impure starch of the laundress) obtained from different plants, are found, when examined under the microscope, to differ in size and form. Some are spherical, others elliptical, flask-shaped, polyhedral, &c. Hence this method of examination affords a ready means of detecting fraud in the substitution of one kind of grain for another. Starch granules, although so very minute, are composed of a fine and delicate membrane, enclosing a fine mealy powder. It may be compared in some respects to a common pea, in which the legumen is enclosed in a testa or skin. Starch granules are not soluble in cold water, nor is PROCURING OBJECTS. 75 iodine capable of acting on them while the membrane enclos- ing its contents remains whole. If the granules be triturated or immersed in hot water, the membrane will be rupturecl, and iodine will then turn them blue. Starch is readily separated from wheat, potato, arrow-root, &c., by repeated washings in cold water. To obtain it from rice, the grains should be mace- rated for a few days, and to prevent the decomposition of the gluten, a little soda should be added to the macerating water. Under the microscope, the surface of starch-grains often appears corrugated, and each of them has one or two bright spots, called the hilum, which is supposed to be the part where the starch adheres to the cell. See Fig. 25. a, represents starch cells of the pea, showing grains of starch in the interior; 6, separate grains of starch, with strise and hilum ; c, granules of wheat-starch ; d, sago meal ; e } rice-starch ; /, potato- starch ; g, isolated cells of rhubarb, containing starch-granules. Under polarized light they present the beautiful phenomenon of the black cross. They should be mounted dry, and protected from the pressure of the upper glass by a rim of thin paper. 76 THE MICROSOOPIST. Seeds are generally opaque objects, and present a great variety of beautiful and interesting forms. Hard Tissues, the stones and shells of nuts, &c., are pre- pared like bone, &c., by cutting and grinding. Some require the lapidary's wheel. Rapliides, or crystals from the interior of plants. If the leaf or bulb of a common hyacinth be wounded, a discharge of fluid ensues ; if this be received on a slide and submitted to the microscope, a number of minute acicular bodies will be observed floating in the liquid. They are called raphides. They are common in many plants. Fig. 26, a. represents cells of Fig. 26. the beet-root, containing conglomerate raphides ; b, octohedral and prismatic crystals of oxalate of lime in the cells of an onion. By scraping hickory, or other bark, on to a slide, moistening it with the breath, and blowing off the woody par- ticles; or by placing a part of the ashes of a burnt maple leaf, coat of an onion, &c., on a slide, such crystals may be seen. They may be mounted dry or in balsam. Mosses are supposed to be destitute of woody fibre and vas- cular tissue. When a leaf is carefully examined, the septa PROCURING OBJECTS. 77 which divide the cells are sometimes found to take a spiral course. To observe this structure, soak the moss in water, to expand the cells. It is essential, in collecting mosses, to preserve the theca or seed-vessel, for without it the genera cannot be determined; while this part, with the calyptra and operculum, are the most valuable for the microscope. Algae. Are interesting objects. The green, mucous, slime- like matter in damp garden walks, and the hair-like weeds in ditches, are examples of fresh-water algae. The sea-weeds of our coast are marine algae, and are often found having zoo- phytes adhering to them; they are then splendid opaque ob- jects. For mounting in balsam, the smaller kinds, of a bright scarlet color, are the most valuable. ferns. The genera are mainly distinguished by the posi- tion and arrangement of the organs of reproduction. These are mostly on the under side, or along the margin of the leaf or frond. They are best examined as opaque objects. They should be collected before they are quite ripe. The spores (seeds) are usually enclosed in brown capsules, each having an elastic ring about its equator, which when ripe bursts, and the spores are dispersed to a distance. Spores may be mounted either as transparent or opaque objects. The development of ferns may be observed by placing the spores in moistened flannel and keeping it at a warm temperature. At first a single cellule is produced, then a second, and so on. After this the first cellule divides into two, and then the others, by which a lateral increase takes place. Lichens and Fungi afford interesting objects. The various kinds of mildew upon vegetable substances are familiar ex- amples of minute fungi. Organic Fabrics possess much interest in a commercial point of view, in addition to the curiosity arising from the 7* 78 THE MICROSCOPIST. manner in which the threads or bundles of fibres are woven or interlaced. For this purpose they should be examined as opaque objects on a black ground, with a magnifying power of from 30 to 60 diameters. The fibres of cotton are readily distinguished under the microscope from those of linen, wool, &c. Cotton fibres are tubular, and are formed' of pure cellular tissue. These tubes, from the thinness of their sides, often collapse and appear like flat ribbons or bands. The reason assigned for the preference given to linen (flax) over cotton for lint, for surgical purposes, is that the fibres of the former are solid cylinders of woody fibre, while the edges of the flattened bands of the latter are supposed to irritate the rig. 27. wounds. Fig. 27 exhibits the different appearance of these fibres under the microscope; a, fibres of flax; b, cotton fibres; c, filaments of silk ; d, wool of sheep. Circulation in Vegetables. The circulation in plants, termed cydosis, is a revolution of the fluid contained in each cellule, PROCURING OBJECTS. 79 and is distinct from those surrounding it. It can be observed in all plants in which the circulating fluid contains particles of a different refractive power or intensity, and the cellules are of sufficient size and transparency. Hence all lactescent plants, or those having a milky juice, with the other conditions, ex- hibit this phenomenon. The following aquatic plants are generally transparent enough to show the circulation in every part of them : Nitella ~kyalina y Nitella translucens, Chara vulgaris, and Caulinia fragilis. In the Frogbit (Hydrocharis), it is best seen in the scales surrounding the leaf-buds, with a power between 60 and 200 diameters. The jointed hairs of the filament of the anther in Trandes- cantia Virginica (Spiderwort) ; the delicate hairs on the leaf- stalk of Senecio vulgaris (Groundsel) ; and a section of the leaf of Vallisneria spiraliSj will show the circulation, especially when viewed with a high power. For the following recapitulatory list of plants, which may be used in microscopic examinations, the author is indebted to Balfour's Class Book of Botany, Edinburg, 1852. 1. Cells and Cellular Tissue. Sea-weeds; rice-paper; inde- pendent cells with nuclei, in yeast plant (Torula Cerevisias) ; cells with nuclei and nucleoli in ripe fruit of strawberry, in the onion bulb, and in ovules or very young seeds; cells united in a linear series in common mould, conferva, and many hairs ; branching cells in many hairs, and in some moulds, as Botrytis; cells united in fours in pollen of Acacia, and in some species of sea-weeds ; cells thickened by deposit of lignin, in the shell of the Cocoanut, and Attalea funifera or Piacaba palm, in the stone of the peach, cherry, and nut, in the seed of the Ivory palm and Date, in the gritty matter of the Pear; cells with siliceous covering in Diatomacese. Porous cells in Elder pith, in stem of common garden Balsam (Balsamina horten- sis), in the outer covering of the seeds of Gourd and Almond, 80 THE MICROSCOPIST. in the wing of the seed of Lophospermum erubescens, and in Calempelis scaber. Spiral cells in leaves and stems of many orchids, as Onicidium and Pleurothallis ruscifolia, in garden Balsam, in the leaf of Sphagnum, the fructification of Liver- worts, the winged seed of Sphenogyne speciosa. Annular cells in Opuntia. Filamentous cells in Mushrooms and Agarics. Hexagonal cells in pith of Elder. Stellate cells in Rush. Ciliated moving cells in Vaucheria, Fuci, and Chara. Professor F. Schulze states, that by means of nitric acid and phosphate of potash, the cells of plants, young or old, hard or soft, may be perfectly isolated for microscopic examination. 2. Vessels and Vascular Tissue. Woody tissue in the stem of ordinary trees ; the fibres may be separated by maceration from the inner bark of the Hemp-plant, Flax-plant, New Zea- land Flax, Mallows, &c., Disc-bearing woody tissue in Scotch Fir, Weymouth Pine, Araucaria, Altingia excelsa, Cycas, Winter's bark tree, Illicium. Dotted vessels in stem of Willow, Sugar-cane, Pitcher- plant. Spiral vessels in Oncidium bicolor, Banana, and Plantain ; most liliaceous plants (as Hyacinth, Lily, and Crinum), leaf of Geranium and Strawberry, Cabbage, Lettuce, Asparagus shoot; branched spirals in Long-kek and Anagallis. Annular vessels in Opuntia vulgaris, Leek, Equise- tuml Telmateia. Reticulated vessels in garden Balsam. Sca- lariform vessels in Tree Ferns, Diplazium seramporense, As- plenium pubescens, Osmunda. Lactiferous vessels in various species of Ficus, as the India-rubber fig (Ficus elastica), Gutta- percha plant (Isonandra Gutta), Euphorbias, Lettuce, Dande- lion, Celandine, Goatsbeard. 3. Contents of Cells. Starch-cells in Potato, angular starch- granules in Rice, compound starch- granules in Arrow-root, peculiar starch-grains in the milky juice of Euphorbia. Air- cells and lacunae in the Rush, Sparganium ramosum, Lim- nocharis plumieri, and other aquatic plants. Cells with PROCURING OBJECTS. 81 raphides of oxalate of lime in Rhubarb root, cells with aeieular crystals in Hyacinth, cells with octohedral and prismatic crys- tals in Onion and Squill. Oil-cells in rind of Orange and Lemon, in leaves of Hypericum, and of the Myrtle order. Chlorophyll cells in Mosses, Vallisneria, Chara; cells with coloring matter in leaf of Rottlera tinctoria, and in petals. ANIMAL TISSUES, ETC. INFUSORIA. These minute animals, some of which are only the 2 smooth P ar ^ f an i Qcn lu diameter, are extremely numerous. Between 700 and 800 different species have been discovered and described. Dr. Ehrenberg, to whom we are indebted for much of our knowledge respecting the ani- malculse, divides them into two classes, i. e., Polygastrica and Rotatoria. The first class is so named from their possessing a digestive apparatus composed of many globular vesicles, which perform the functions of stomachs. The Rotatoria are so called from their possessing rotary organs about their mouth. These are much more highly organized than the others. The Polygastrica increase by self-division, or by the growth of gemmules or buds upon their bodies ; the Rotatoria are herma- phrodite, and oviparous. Many animalculce are loricated; or protected by a shell, or shield, which is generally siliceous : others are destitute of such an appendage. The following table exhibits the families or groups into which this interesting department of animal life has been di- vided by Ehrenberg. Those who wish further information re- specting them are referred to his work "Die Infusionsthier- chen," or to Pritchard's "History of Infusoria, Living and Fossil." Dr. Mantell's work on Animalcules contains also much valuable information. 82 THE M I C R O S C P I S T. CLASS I. POLYGASTRICA. 1 Self- ( division > complete. 1 illoricated or shell-less, loricated or shelled, Monadina. Cryptomonadina. 1 Body destitute of appendages. (No foot-like ' processes.) Gymnica. Form < of body Selfdivi- sion in- complete, formed in clusters. ' self- dividing on all ( sides (globular), j Volvocina. , Vibriona. Closterina. 1 f ,'i i ,^,: , .,,*.., i Dinobryina. 8 1 Foot-like processes variable. Pseudo-poda. C compound foot-like process < i.-,, + A j from one aperture, j lo "cated, ^ gimple foot-like process from L 1 one or from each aperture, Amoebaea. Arcellina. Bacillaria. 1 Hairy ( illoricated, Cyclinida. "^ 'One receiving and f xeridinaea. 1 discharging orifice only for nutrition. j illoricated, 1 loricated, ...... Vorticellina. Ophrydina. ? Anopisthia, ^ 3 Two ditto orifices, f k illon n 4-^/1 Enchelia | one at eacu extremity. \ loricated, Colepina. "3 . Enantritena. i a<; ',*. 1 Orifices situated f C mouth furnished with pro- l illoricated,^ boscis, tail absent, Trachelina. ^77 ? U . e ' 1 1 moi ith anterior, tail present, Ophryocercina. 1 ' eta ' (.loricated, " - - - - - - Aspidiscina. 1 Orifices abdominal. Catotreta. ^ illor ( loric , , ( locomotive organs cilii, catecl, do do Tarioug _A p J Kolpodea. Oxytrichina. E up lota. CLASS II. ROTATORIA. wifv. o c,;mwio f margin of cilii-wreath entire. ( illoricated, Icthydina. Tinuous th of " 1 BbWrocfta. j loricated, Oecistina. cilH ' f < mar e in of * li thlobed or^. noricated5MeKalotrochaea- (Jfonofrocfta.) ScJiizotra cM. 1 loricated ' Floscularia. (with the cilii-wreath divided into( M 1n _; / , oto j TT^ati . several series. \ lloricated, Hydatmea Polytrocha. ^loricated, Luchlanidota. (Sortl^cha ) \ With tbe dl iwo r s e e a ries diVided Int ^ "l^icated, Philodinaea. rit : s - ^loricated, Brachionaea. PROCURING OBJECTS. 83 In reference to obtaining infusoria, some persons imagine that if they procure a portion of fetid ditch-water, or take a few flowers, &c., and macerate them in water, they will be furnished in a few days with all the varieties they may desire ; but this is not the case. Infusoria will of course be found, but they will be only of the most ordinary kinds. To obtain those of higher interest, some degree of skill is required. Many remarkable species have been taken in meadow-trenches in the slowly running water, after a summer shower, especially about the time that the first crop of hay was mown. Among healthy water-plants, the various kinds of Vorticellina (Sten- tors and Vorticellsej or trumpet and bell-shaped infusoria), and Rotatoria (wheel-animalcules), may be sought for with success. The stems of aquatic plants have often the appearance, to the naked eye, of being encased with mouldiness, or rancor, which on being examined with the microscope, proves to be an ex- tensive colony of arborescent animalcules. The dust-like stratum sometimes seen on the surface of ponds, and the shining film which sometimes covers water-plants, assuming various hues of red, brown, yellow, green, and blue, is caused by the presence of infusoria, some of which are very beautiful. Many species live in the clean fresh water of rivers, lakes, and springs; and the brine of the ocean, Imewise, as well as the mould on the surface of the earth, has its microscopic inhabi- tants. In order to procure animalculse, provide yourself with a number of clean, wide-mouthed, glass phials, fitted with proper corks, not glass stoppers, so that the air may have access to them, at least to some extent. Have also a rod, or walking- cane, which may be prepared with a spring-hook and ferule for fastening a phial on its end, although a piece of twine is a good substitute. On reaching the pond, &c., carry the phial (attached to the rod) in an inverted position, and when at 84 THE MICROSCOPIST. proper depth, or in the neighborhood of water-plants, it should be turned quickly, when animalculae, &c., will run into it. Water-fleas and Daphnise should be frightened away by shak- ing the phial before turning. If in the phial, they go quickly to the bottom, and the upper water can be poured off. Exa- mine the water with a pocket lens, and preserve the animal- culse. The indications of the presence of infusoria are specks mov- ing about in the water, or an apparent mouldiness around the stalks of the water-plants, &c., which may have been caught in the phial. If these appearances be not discerned by the magnifier, the water may be thrown away, and another place resorted to. A small portion only of vegetable matter should be preserved in the phial, as its decay may soon kill the ani- malcules. Small newts and many larvas should be preserved; the for- mer especially, as they eat up the Daphniae, Monoculi, &c., that destroy the Vorticellse. In the branchiae of young newts, too, and in their feet, the circulation of the blood is beautifully seen. The phial should sometimes be laid horizontally on the bot- tom of the pond, and scrape the surface of the mud. This should be put in a large jar with water, and in a day or two the animalculae will be on the surface of the mud, from which they can be removed with the fishing-tubes (see page 49), and placed under the microscope. If the creatures are too minute to be seen easily with the naked eye, pour a little water from the vessel containing them into a watch glass, and place it on a piece of card-board, ren- dered half black and half white. The white ground will make the dark specimens apparent and vice versa. They can then be seen with the pocket lens, and taken out with the fishing- tubes. PROCURING OBJECTS. 85 In order to show the stomachs, cilia, &c., of animalcule under the microscope, rub some pure sap-green or carmine on a palette or plate of glass, and add a few drops of water. If the glass 'be now held on one side, a portion of the coloring matter may be put into the water on the slide containing the animalculse. If they be vorticellse or rotiferse, the particles of coloring matter will show the vibratile actions of the cilia, whilst other particles swallowed by the animals, will give a rich tint to the compartments of their alimentary canal. Fossil Infusoria. A great number of infusorial earths may be mounted in balsam (test objects dry, however) without washing, &c., but others must be repeatedly washed or digested in acid. For the skeletons or shields in carbonate of lime, consisting mostly of Polythalamia, or many-chambered shells, Professor Ehrenberg has directed to place a drop of water on the slide, and put into it as much scraped chalk as will cover the fine point of a knife, spreading it out, and leaving it to rest a few seconds; then withdraw the finest particles, which are suspended in the water, together with most of the water, and let the remainder become perfectly dry. Cover this with Canada balsam, and hold it over a lamp until it becomes slightly fluid without froth. Siliceous Shields of Infusoria, such as those in guano, Richmond earth, &c., require to be well washed and boiled or digested in nitric or hydrochloric acid. After this, a small quantity of the sediment in which they are contained should be placed on a number of slides, and those containing the best specimens laid aside for mounting. In guano and Richmond earth are found most beautiful saucer-shaped shells, having hexagonal markings, which have received the name of Cosci- nodiscus, or sieve-like disc. They vary in size from T g P3 W n Q , 1 |U 1 ggg gaji i I g 3.1 fl! 2- J-g H s , a w =3 o -u,^; o -g I c ? :3 |5|g 3 ! ^^ a'i-as a j j i i * a i ; Sg^'S-3o S^S &ii- O H ^ O 150 THE MICROSCOPIST. FRO OF ER MM ill! I s O O HO o ^J 69 ^ Ss MORBID STRUCTURES, 4 111 l|| ^2 JTB! ETC. 153 ^ t-'d jaj'Odi'^i J|334 M tOT" S o S -T S I Jr-|iK i g -a 5 tJ-S ^= So o d o S .2 * -B 5 fi 3 |l ^ SsSM- -i ^|ol|| J b. as < "^ "^ "i< H il??lll' i^J-aSS^iS lillllill .0 lSd^S ! ,2-~ O 03 *> ^ -2 H o fl 3 d p T3 tn O^ 53 -at J^ I 154 THE MICROSCOPIST. 3 S5 2 rt O o5 sS B 63 (M O S'Sfig - ijjffj Mill iiiin 1 al DATI H IN White globuL those of tt of an enveli smallest m< 111! ^ - MORBID STRUCTURES, ETC. 155 * II if -I 5 Iffi i lii'.j'l tjjljf *Ss!| ss IlllsJl a 5 "**! Pit _ s sj-sllfl g^sSISS SS 3JIJ* OD {,_, -(j *^ y> ^ o >,ji a 111?? s*^s ^0^-3 J'2- Stl I 111" JPI ^ fl O> 03 S^ ^ S 2 8 156 THE MICROSCOPIST. aasoarcoo si MORBID STRUCTURES. ETC. 157 MI* sislfillsl sxiaias *l*tfljl~B anna ^ 5 -r TMIYM. ann 4 JO IVH1IK AO "108 H3A1I8 ao aivaiiN aax jo noixmos C^^1*S fr- H9 a |6 fl Sjf5ifi | 11 * fl oiov OIHYIHYX aiov OIIYXO .2^; aiOY DIIZOY .2 ^ * sainaoao 3HX dO KHOJ 11^ CHAPTER XL ON MINUTE INJECTIONS. MERE dissection, with the most artful management of the scalpel, cannot make a full exhibition of the true structure of animal bodies. The arteries are found, after death, to be emptied of. their contents, and the blood is coagulated in the veins, which appear much collapsed; hence anatomists, in order to examine the circulatory apparatus, are under the necessity of filling these vessels by means of injection, in order to distend them as much as possible, that their ramifica- tions may be clearly seen. More especially is this necessary when it is desired to make an exhibition of the minute capillaries, which are so variously arranged in the different textures and organs of the body. These small vessels, too, require the aid of the microscope to show their size, form, and arrangement. The ordinary coarse injection may be made by melting to- gether 16 ounces of bees' -wax, 8 ounces of resin, and 6 fluid- ounces of turpentine varnish, adding such coloring matter as may be desirable, as 3 ounces vermilion, 2 ounces King's yellow, 10 ounces blue verditer, or 5 ounces flake-white. This, injected into the blood-vessels by a proper syringe, having its pipe fastened in one of the largest of those vessels, is abundantly sufficient to show the course of the principal arteries and veins. The parts so injected may then be dis- ON MINUTE INJECTIONS. 159 sected for this purpose, dried, and varnished, and form excellent illustrations of anatomical lectures. When, however, it is desired to demonstrate the capillaries, a finer injection and more delicate manipulation are required. Indeed, it is so difficult an art, and success is so dependent on the combination of various circumstances, that the most ex- perienced are often defeated in their efforts. Yet some of the finest injections I have ever seen were made by those who attempted it for the first time. For minute injection (as it is called), the most essential in- strument is a proper syringe. This should be made of brass, of such a size that the tip of the thumb may press on the head or handle of the piston-rod when drawn out, while the body is supported by two of the fingers of the same hand. Fig. 50 represents a syringe, with which I have succeeded in making some excellent preparations. A is the cylindrical brass body, on the top of which screws the cap, B, a leather washer being interposed to render it more air-tight. C is the piston, which is of brass, covered with wash-leather. The bottom of the syringe, D, also unscrews, for convenience of cleaning. E is a stop-cock, on the end of which another stop- cock, F, fits closely. On the end of this, one of the injection- pipes, G-, which are of different sizes, may be placed. The transverse wires, across the injection-pipes, are designed for the better security of the pipe in the vessel into which it is fixed ; the thread being tied behind them so that it cannot slip for- wards. A half-dozen pipes, at least, are necessary to accom- pany each instrument. In addition to the syringe, a large tin vessel to contain hot water, with two or three lesser ones fixed in it for the injec- tions, will be found useful. For very minute injections, as in the Mollusca, &c, a caout- chouc bottle, with a capillary steel tube mounted in wood, 160 THE MICROSCOPIST. ivory, or iron, is recommended by Talk & Henfrey, after Straus Durekheim. The air should be pressed out of the bottle, and Fig. 50. the pipe placed in the liquid, which will rush in to fill the vacuum, and it is ready for use. They also recommend a tube, or pipette, with flexible stems, so constructed as to receive jets ON MINUTE INJECTIONS. 161 of various sizes. This is used by placing the end of the pipette in the mouth, and exhausting the air on forcing the fluid in the vessels. To prepare the material for injecting: Take of the finest and most transparent glue, one pound; break it into small pieces, put it into an earthen pot, and pour on it three pints of cold water; let it stand twenty-four hours, stirring it now and then with a stick ; then set it over a slow fire for half an hour, or until all the pieces are perfectly dissolved J skim off the froth from the surface, and strain through a flannel for 'use. Isin- glass, and cuttings of parchment make an excellent size, and are preferable for very particular injections. The size thus prepared may be colored with any of the fol- lowing: Red. To 1 pint of size, 2 ounces of Chinese vermilion. Yellow. Size, 1 pint, -chrome yellow, 2J ounces. White. Size, 1 pint, flake-white, 3J ounces. Blue. Size, 1 pint, fine blue smalts, 6 ounces. It is necessary to remember that whatever coloring matter is employed, must be very finely levigated before it is mixed with the injection. This is a matter of great importance, for a small lump or mass of color, dirt, &c., will clog the minute vessels, so that 'the injection will not pass into them, and the object will be defeated. The mixture of size and color should be frequently stirred, or the coloring matter will sink to the bottom. Respecting the choice of a proper subject for injecting, it may be remarked, that the injection will usually go farthest in young subjects; and the more the creature's fluids have been exhausted in life, the greater will be the success of the injec- tion. Owing to the contraction of the vessels, it is necessary to wait from one to three days after death before attempting the 14* 162 THE MICROSCOPIST. injection. Yet it should not Tbe deferred so long that the ves- sels may become softened, or the injecting material will be ex- travasated. To prepare the subject, the principal points to be aimed at are to dissolve the fluids, empty the vessels of them, relax the solids, and prevent the injection from coagulating too soon. For this purpose it is necessary to place the animal, or part to be injected, in warm water, as hot as the operator's hand will bear. This should be kept at nearly the same temperature for some time 'by occasionally adding hot water. The length of time required is in proportion to the size of the part, and the amount of its rigidity. Ruysch (from whom the art of injecting has been called the Ruyschian art) recommends a previous maceration for a day or two in cold water. When the size and the subject have both been properly pre- pared, have the injection as hot as the finger can well bear. One of the pipes, G-, Fig. 50, must then be placed in the largest artery of the part, and securely tied. Put the stop- cock, F, into the open end of the pipe, and it is then ready to receive the injection from successive applications of the syringe, A. The injection should be thrown in by a very steady and gentle pressure on the end of the piston-rod. The resistance of the vessels, when nearly full, is often considerable, but it must not be overcome by violent pressure with the syringe. If the resistance suddenly ceases or diminishes, it indicates that some vessel is ruptured, and the process must be stopped. If it happens at the commencement of the operation, and the vessel cannot be tied, the injection has failed. When as much injection is passed as may be thought advisa- ble, the preparation may be left (with the stop-cock closed in the pipe) for twenty-four hours, when more material may be thrown in. The first part of the injecting material forming about a third ON MINUTE INJECTIONS. 163 or fourth part of the whole, should be very fluid, so as to be capable of penetrating the smallest vessels ; afterwards the thicker or coarser portion should be thrown in so as to push the first before it. As the method of injecting the 'minute capillaries with colored size is often attended with doubtful success, various other plans have been proposed. Ruysch's method, according to Rigerius, was to employ melted tallow, colored with vermi- lion, to which, in the summer, a little white wax was added. Mr. Rauby's material, as published by Dr. Hales, was resin and tallow, of each two ounces, melted and strained through linen ; to which was added three ounces of vermilion, or finely ground indigo, which was first well rubbed with eight ounces of turpentine varnish. Dr. Monro recommended colored oil of turpentine for the small vessels, after the use of which he threw in the common coarse injection. Professor Breschet frequently employed with success milk, isinglass, the alcoholic solution of gum-lac, spirit varnish, and spirit of turpentine; but he highly commends the coloring matter extracted from campeachy, fernambouc, or sandal woods. He says, "The coloring matter of campeachy wood easily dis- solves in water and in alcohol; it is so penetrating that it be- comes rapidly spread through the vascular networks. The sole inconvenience of this kind of injection is, that it cannot be made to distend any except most delicate vessels, and that its ready penetration does not admit of distinguishing between arteries, veins, and lymphatics." He also recommends a solu- tion of caoutchouc. Another process, which may be termed the chemical process, was published in the Comptes Rendus, 1841, as the invention of M. Doyere. though the credit of first suggesting it is due to Dr. Goddard, of Philadelphia. According to this, an aqueous solu- tion of bichromate of potass is propelled into the vessels; and 164 THE MICROSCOPIST. after a short time, in the same manner and into the same ves- sels an aqueous solution of acetate of lead is injected. This is an excellent method, as the material is quite fluid, and the precipitation of the chromate of lead, which takes place in the vessels themselves, gives a fine sulphur-yellow color. A red precipitate is obtained by iodide of potassium and bi- chloride of mercury ; blue, by the ferrocyanide of potassium and peroxide of iron ; &c. Dr. Goadby has improved upon the process last named by uniting to the chemical solutions a portion of gelatine. The following is his formula, originally published in the London Lancet, and again in the Medical Examiner, March, 1850. Saturated solution of bichromate of potash, 8 fluid ounces; water, 8 ounces ; gelatine, 2 ounces. Saturated solution of acetate of lead, 8 fluid ounces; water, 8 ounces; gelatine, 2 ounces. Dr. Gr. gives the following remarks respecting this process : "The majority of preparations, thus injected, require to be dried, and mounted in Canada balsam. Each preparation, when placed on a slip of glass, will necessarily possess more or less of the colored infiltrated gelatine (by which, he alludes to the gelatine, colored by the blood, which, together with the acetate of potash resulting from the chemical decom- position, may have transuded through the coats of the vessel), which, when dry, forms, together with the different shades of the chromate of lead, beautiful objects, possessing depth and richness of color. The gelatine also separates and defines the different layers of vessels. By this injection the arteries are always readily distinguishable by the purity and brightness of the chromate of lead within them, while the veins are de- tected by the altered color imparted by the blood. " Those preparations which require to be kept wet, can be ON MINUTE INJECTIONS. 165 preserved perfectly in my B fluid specific gravity 1-100; the A fluid destroys them. " I would recommend, that the slips of glass employed for the dry preparation be instantly inscribed with the name of the preparation, written with a diamond, for, when dry, it is very difficult to recognise one preparation from another, until the operator's eye be educated to the effects of this chemico- gelatinous injection. Where so much wet abounds gummed paper is apt to come off. " When dry, it is sufficient for the purpose of brief exami- nation by the microscope, to wet the surface of a preparation with clean oil of turpentine; immediately after examination, it should be put away carefully in a box, to keep it from the dust, until it can be mounted in Canada balsam. " Although highly desirable, as the demonstrator of the capillaries of normal tissues, I do not think this kind of injec- tion fitted for morbid preparations, the infiltrated gelatine producing appearances of a puzzling kind, and calculated to mislead the pathologist. "In preparing portions of dried, well-injected skin, for exa- mination by the microscope, I have tried the effect of dilute nitric acid, as a corroder, with very good results. But, proba- bly, liquor potassae would have answered this purpose better. "When size injection is to be employed, colored either with vermilion or the chromate of lead, the animal should be pre- viously prepared by bleeding, to empty the vessels: for if they be filled with coagulated blood, it is quite impossible to transmit even size, to say nothing of the coloring matter. Hence the difficulty of procuring good injections of the human subject. "But with the 'chemico-gelatinous' injections no such pre- paration is necessary, and success should always be certain, for the potash liquefies the blood, while constant and long-con- 166 THE MICROSCOPIST. tinned pressure by the syringe drives it through the parietes of the vessel into the cellular tissue. The large quantity of in- filtrated blood the invariable concomitant of my process characterizes this from all other modes of injecting, and is a distinctive feature of these preparations/' Still another, and in some respects a more certain and con- venient plan, has been employed by Dr. Goddard of Philadel- phia. It consists in adding a quantity of sulphuric ether to the finely levigated coloring matter, which is also first ground or mixed with linseed oil, in the manner employed by painters. Upon this plan (as well as upon the last named) I have suc- ceeded in making some beautiful injections of the smallest capillaries, yet I have sometimes failed, owing to the too rapid evaporation of the ether, and the clogging up of the vessels from the early deposition of the solid coloring matter. I have also observed that after the ether has evaporated from the vessels, the particles of coloring material cohere with too little tenacity, so that on putting a section of injected tissue into" turpentine, &c., the color has been washed out from the cut ends of the larger vessels. Perhaps a solution of gum nias- tich, &c., in ether, colored with fine vermilion, &c., will answer the indications better. Whatever mode of injection be adopted, it is important that the operator be supplied with sufficient material. The quantity which can be used will surprise any one unaccustomed to the process. A foetus maybe injected by the umbilical vein; a uterus, by the hypogastric arteries; the head, by the carotids; the liver, mucous membrane of the intestines, &c., by the portal vein ; an extremity, by the principal artery ; &c. The liver, kidney, &c., may be well injected out of the body ; and it is often desirable to use various colors for the different sets of vessels. It will require some practice, however, to judge ON MINUTE INJECTIONS. 167 how much pressure is necessary to fill but a single set of vessels. After injection, a considerable time must be allowed for dry- ing. Thin slices may then be cut off, and mounted either in balsam or fluid. The villi of the intestines are beautifully exhibited after in- jection. They should be macerated a little while in water, or washed with a syringe, to remove the epithelium and mucus. Animals that feed chiefly on vegetables have longer villi than others. The lungs may be injected by the pulmonary artery or vein- In a foetus, however, all the organs may be injected from the umbilical vein. The author's injections and specimens of in- jected lungs confirm the view of Mr. Rainey, that the essen- tial and only true organs of the aeration of the blood are the pulmonary capillaries. Injections of the skin may be made by the vein of an ex- tremity. They may then be mounted in fluid, or after drying, sections may be made and put up in balsam. The vessels of the choroid membrane and ciliary processes of the eye are often injected in a foetus ; or in the case of an animal, as a cat, rabbit, &c., injected from the heart. The preparation should be kept in fluid. Many parts, after injection, require to be macerated in water, or corroded by dilute muriatic acid, &c., in order to exhibit the ramifications of the small vessels. They should be very care- fully handled, or moved, in the macerating liquor, as the slight- est force may break the vessels. When corroded, the pulpy flesh is to be carefully washed away by placing it under a stream of water, flowing very slowly ; or by the use of a syringe with water. The lymphatics are usually injected with quicksilver, but M. Rusconi and Professor Breschet, have abandoned this me- thod for the colored material, on account of the mercury fre- 168 THE MICROSCOPIST. quently rupturing by its weight the thin, lymphatic vessels and reservoirs. The first-named gentleman, in his researches on the lymphatics of reptiles, employs in place of the usual injecting tube of Walter (used with the mercury), a small silver syringe, together with a kind of trocar, of which the canula is formed from the quill of the wing-feather of the quail or partridge, the trocar being a tolerably large-sized needle, the point of which has three facets. When desirous of in- jecting the lymphatic system of a lizard, tortoise, &c., he re- marks : " I seize with a small pair of forceps the mesentery, close to the vertebral column, where the reservoir of the chyle is situated, and I introduce into it the point of the trocar ; I then retain the quill and withdraw the needle from the tube. This done, I seize with the small forceps the quill, and intro- duce into it the small extremity of the syringe, and push the piston with a force always decreasing." He recommends colored wax, mixed with nut-oil, for the injection. CHAPTER XII. EXAMINATION OF URINARY DEPOSITS. THE chemical composition of the urine and urinary deposits has within a few years past attracted much attention, and has contributed much to our knowledge respecting the nature of diseases and their diagnosis. To examine these, the microscope is often an essential instrument. Deposits of uric acid and its combinations (called red, or yellow-sand sediments), occur in fever ; acute inflammation ; in rheumatism; in phthisis; in all the grades of dyspepsia; in all or most stages of diseases attended with arrest of per- spiration ; in diseases of the genital apparatus ; from blows and strains of the loins ; from excessive indulgence in animal food ; or from too little exercise. The deposition of earthy phosphates (white deposit), should be regarded as of serious importance, always indicating the existence of important functional, and frequently of organic disorder. According to Dr. Bird, they always exist simul- taneously with a depressed state of nervous energy, often general, rarely more local, in its seat. Deposits of oxalate of lime are regarded by Dr. G-. Bird as by no means so rare as is generally supposed. He believes that ife owes its origin to sugar, and is caused by derangement of the digestive organs. The urine may contain all or any of the elements of the 15 170 THE MICROSCOPIST. blood. The serum may be effused alone, or be accompanied with the red globules. Whenever the elements of blood appear in the urine, there is ample proof of the existence of active or passive hemorrhage of the kidneys, or urinary tract. Albuminous urine occurs in Bright' s disease, dropsy after scarlatina, &c. Pus is met with in the urine as the result of suppuration of the kidney, or of some part of the genito-urinary mucous mem- brane, or of abscesses of the neighboring viscera, opening into the urinary passage. The presence of sugar is not uncommon in dyspepsia, and when excessive is diagnostic of diabetes mellitus. Kiestein is a whitish, greasy, opalescent pellicle, sometimes found on the urine of pregnant women. To examine urinary deposits with the microscope, allow the urine to stand; decant the supernatant fluid; pour the remain- der into a watch-glass ; draw off the small quantity of fluid remaining after a short repose, by means of a pipette ; and then place it on the stage of the microscope. When, however, it is necessary to use high powers, a drop of the sediment should be placed on a glass slide and covered with thin glass. If it is desired to mount the object for future examination, it can be covered, when dry, with a drop of Canada balsam, and surmounted with the thin glass. Very transparent objects should be kept in fluid, as weak spirit, water saturated with creasote, or G-oadby's fluid. HEALTHY URINE holds in solution a variety of substances, both organic and inorganic. Chemists have not yet succeeded in insulating all its ingredients for examination, but the most important of its solid materials are urea, uric acid, hippuric acid, vesical mucus and epithelial debris, animal extractive, ammoniacal salts, fixed alkaline salts, and earthy salts. EXAMINATION OF URINARY DEPOSITS. 171 The amount passed by an individual during each twenty-four hours, varies from twenty to fifty ounces, holding in solution from six hundred to seven hundred grains of solid matter. When kept for some time it gradually becomes turbid, and de- posits a sediment of earthly phosphates, previously held in solution by the slight excess of acid present. If kept still longer, it gradually putrefies, and, becoming concentrated by evaporation, deposits small crystals of chloride of sodium, phosphates, and other salts, and eventually becomes covered with a grayish-colored mould. Urea 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. The proportion of urea in healthy urine averages fourteen or fifteen parts in the one thousand. Pure urea may be obtained by first converting it into the oxalate, which is done by adding a strong solution of oxalic acid in hot water, to urine previously concentrated to about one-eighth its bulk, and filtered to free it from the insoluble sediments of phosphates and urates. The crystal of oxalate of urea thus obtained, a, Fig. 51, should be dissolved in hot water, and the solution treated with pulverized chalk as long as effervescence is produced. The urea remains in solution, and may be puri- fied by boiling with animal charcoal, after which it may be crystallized, in four- sided prisms, by careful evaporation. Nitrate of urea may be obtained in crystals, b, Fig. 51, by concentrating urine to about one-half its bulk, and adding an equal quantity of nitric acid. If urea be suspected in excess, a drop of the urine, without concentration, may be treated with nitric acid under the microscope. The proportion of uric acid in the healthy secretion varies from 0-3 to 1-0 in 1000 parts. Its forms will be represented when we treat of the examination of urinary deposits. It may be obtained from urine concentrated to half its bulk, by adding 172 THE MICROSCOPIST. a few drops of hydrochloric acid ; and allowing it to stand few hours in a cool place. Fig. 51. Hippuric Acid is generally present in a small quantity in healthy urine, and in certain forms of disease, especially where a vegetable diet has been adopted. Fig. 52 represents some Fig. 52. of its forms ; a are deposited from an alcoholic solution, and b from a hot aqueous solution. When an excess is suspected in urine, it should be evapo- rated to the consistence of syrup and mixed with half its bulk of strong hydrochloric acid. After a few hours the crystals EXAMINATION OF URINARY DEPOSITS. 173 may be examined with the microscope, when the tufts will probably be seen, colored pink by the admixture of purpu- rine. If it be present only in small quantity, a few detached needle-like or branched crystals may be seen. It is readily soluble in alcohol and hot water, but not in cold water. Vesical Mucus and Epithelial Scales, which may be present, are derived from the internal surface of the bladder and uri- nary passages. The quantity is so small in healthy urine as to be scarcely visible, until, after standing, it has subsided to the bottom of the liquid in the form of a thin cloud. Extractive Matter, includes all the uncrystallizable organic matter found in the residue of evaporated urine, which is soluble in water or alcohol. When in excess, the urine ap- pears more highly colored than usual, a large proportion of what is termed extractive, consisting of coloring matter, as purpurine, &c. Ammoniacal Salts appear to consist chiefly of the muriate and the urate, the latter salt being the form in which the uric acid present in the urine appears to be held in solution. The proportion of ammonia in healthy urine is quite small, but in some diseases, especially in certain kinds of fever, it increases considerably. Fixed Alkaline Salts may be obtained by incinerating the evaporated residue of urine, when a white ash will be left, consisting of a mixture of alkaline and earthy salts; the for- mer may be separated from the latter by dissolving in water, in which the earthy salts are insoluble. The alkaline salts, which in the healthy secretion usually amount to thirteen or fourteen parts in one thousand, consist of the sulphates of potash and soda, chloride of sodium, chlo- ride of potassium, and phosphate of soda. The crystallized residue, after slowly evaporating a few drops on a piece of glass, usually has the appearance represented in Fig. 53. The cross- 15* 174 THE MICROSCOPIST. lets consist of chloride of sodium ; the more plumose crystals are probably phosphate of soda. Fig. 53. The Earthy Salts which form the insoluble portion of the ash, and which usually amount in healthy urine to about 1 part in 1000, consist of the phosphates of lime and magnesia, together with a small trace of silica. These appear to be re- tained in solution in the urine by the small exoess of acid (probably phosphoric) usually present, and may be precipitated from it by supersaturating with ammonia. The precipitate thus formed consists of a mixture of phosphate of lime, and the double phosphate of ammonia and magnesia, which is also called triple phosphate. These, with the abnormal ingre- dients found in morbid urine, &c., will be treated of when we come to the examination of urinary deposits. It must be borne in mind, however, that a spontaneous precipitate of earthy phosphates is not of itself a proof that they are present in excess, for when the urine is acid, as in health, a considera- ble quantity may be retained in solution, while if it be neutral or alkaline, a comparatively small proportion may be precipi- tated. EXAMINATION OF URINARY DEPOSITS. 175 When urinary deposit is examined with the microscope, it will be found either crystalline, amorphous, or organized. When, as is frequently the case, the deposit consists of a mixture of different forms, each of them in succession should be examined, until the nature of the whole deposit is clearly understood. CRYSTALLINE DEPOSITS will probably be either uric acid, pMfesphate of lime and magnesia (from which the triple phos- phate is formed), oxalate of lime, or perhaps cystine. Triple Phosphate. This salt (called also the double phos- phate of ammonia and magnesia) is formed by supersaturating with ammonia. . Phosphate of lime is also precipitated by the same means, but may be distinguished by the microscope. The crystals of the triple phosphate are stellate or triangular prisms, as seen in Fig. 54. They disappear on the addition of acetic acid. Uric (or Lithic) Acid. This salt, like the earthy phos- phates, exists in a small quantity in healthy urine, but as the proportion varies considerably in many forms of disease, its determination when in abnormal quantity affords much assis- tance in diagnosis. It is insoluble in alcohol, and nearly so in dilute hydro- chloric and sulphuric acid ; but it combines with the alkalies, forming salts, which are insoluble or very sparingly soluble in water. The action of nitric acid upon uric acid is characteristic. It will gradually dissolve it, carbonic acid and nitrogen being given off with effervescence, leaving behind a mixture of alloxan (C 8 N 2 H 4 O 10 ), alloxantine (C 4 H 3 N 5 O s ), and other compounds. This may be evaporated nearly to dryness, when a red residue will be left, which, when cold, should be moist- ened with ammonia, which will develope a beautiful purple color, owing to the formation of murexide (C 13 N 5 H 8 ). 176 THE MICROSCOPIST. The crystalline forms of uric acid are various, but appear to be modifications of the rhombic prism. Fig. 54. Fig. 55 represents some of its forms. Oxalate of Lime often exists in the form of minute octahe- dral crystals, varying from ? Joth to .gg^th of an inch in diameter, a, Fig. 56. When allowed to dry on the glass, each EXAMINATION OF URINARY DEPOSITS. 177 crystal appears under the microscope like a black cube, having Fig. 55. in the centre a small white square opening, as shown at 178 THE MICROSCOPIST. This is owing to the rays of light being mostly refracted be- yond the field of vision. On again moistening them, the crys- tals reappear in their octahedral form. Sometimes this salt assumes the forms represented at c, more or less resembling dumb-bells.* This forrn ; like the crystals of uric acid, the * Dr. Fricke, in the American Journal of Medical Science, July, 1850, states as his opinion that the dumb-bell forms of crystals are not oxalate of lime, but disintegrated crystals of uric acid. EXAMINATION OP URINARY DEPOSITS. 179 triple phosphate, &c., is beautifully colored when examined by polarized light; the octahedral variety has little or no effect upon it, being invisible, or nearly so, when the field is dark. If the " dumb-bells" are kept in liquid for any length of time, they gradually pass into octahedra. As the crystals of oxalate of lime are very transparent, and about the same specific gravity as the urine, they may readily escape detection, unless some considerable time is allowed for deposition, or the urine is passed through a filter. Oxalate of lime is insoluble in water, in acetic and oxalic acids, and in solution of potash; but it is readily soluble in dilute nitric and hydrochloric acids. Cystine has occasionally been found as a crystalline deposit and in the form of small calculi. It may be distinguished by being insoluble, or nearly so, in water and dilute acids, but soluble in ammonia, from which small hexagonal crystals are deposited on evaporation. The usual microscopic appearance is represented at a, Fig. 57. At b is the form left from the ammoniacal solution. Fig. 57. oW (J) g>O o" i AMORPHOUS DEPOSITS consist probably of phosphate of lime, urate of ammonia, urate of soda, fat, or chylous matter. Phosphate of Lime. This salt has already been described as existing in urine in conjunction with the phosphate of magnesia. It is thrown down, together with the triple phosphate (before 180 THE MICROSOOPIST. noticed), on the addition of ammonia. The crystalline shape of the triple phosphate, however, readily distinguishes it under the microscope from the amorphous particles of phosphate of lime with which it is usually mixed. The earthy phosphates are readily soluble in dilute acids, from which they are pre- cipitated by ammonia. They are insoluble in a solution of potash. Urate of Ammonia constitutes one of the most common urinary deposits. It is gradually deposited as the urine cools, in the form of an amorphous precipitate, which, with a high magnifying power, appears to consist of minute rounded par- ticles, occasionally adhering together, frequently mixed with small crystals of uric acid, and occasionally with the earthy phosphates. A deposit of urate of ammonia readily dissolves when the urine containing it is gently warmed, and is preci- pitated again when the liquid cools. (The earthy phosphates and uric acid are nearly as insoluble in hot as cold water.) When urate of ammonia is treated with dilute acetic or hydrochloric acid, it is decomposed, and uric acid, is formed. Urate of Soda is often met with in the urine of patients taking medicinally the carbonate or other salts of soda. It re- sembles the urate of ammonia in being soluble in hot water, and in most of its chemical characters, but may be generally recognised without difficulty under the microscope, forming minute globular or granular aggregations, with, occasionally, irregular and curved protuberances. Fat may be recognised by the particles being minute round globules, with dark and well-defined outlines, which dissolve when agitated with ether. Sometimes this substance is mixed with albuminous matter, forming a kind of emulsion, so that no trace of fat can be per- ceived with the microscope. In such cases, the urine may be agitated with a little ether, which will dissolve the fat, and EXAMINATION OF URINARY DEPOSITS. 181 the solution so formed will separate from the watery liquid, and form a distinct stratum on the surface. Chylous Matter may be known by the urine being opaque and milky in appearance, yielding fatty matter when agitated with ether, and containing minute, amorphous, albuminous particles, and perhaps also colorless globules, which may possibly be mistaken for oil globules, from which their insolu- bility in ether distinguishes them. ORGANIZED DEPOSITS may either be mucus, usually mixed with epithelium ; pus ; blood ; or semen. Mucus. If the particles observed with the microscope 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. Epithelial debris may be recognised by the peculiar form of its particles. Mucous urine generally contains a considerable amount of earthy phosphates and other matters. Pus may be known by the particles not being held together by any tenacious matter, but floating freely in the liquid. The granules of pus and mucus present almost the same appearance under the microscope, although the latter may probably be rather smaller and less distinctly granular. Acetic acid renders the interior nuclei visible in both, but it coagulates the fluid portion of the mucus. Even this test may be uncertain, 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. When the quantity of mucus is abundant, however, this test will be sufficient. Blood. When this is suspected in the urine, it may be examined under the microscope for any blood corpuscles that may be in it. If the blood has coagulated, they will probably be entangled in the coagula, and may be forced out by gentle 16 182 THE MICRO SCO PI ST. pressure under a strip of thin glass. If there is no coagula, the liquid may rest for a short time, and a drop from the bot- tom examined. The urine may also be tested for albumen after separating the solid matter by filtering. When the coloring matter of the blood is present, it will coagulate with the albu- men, giving it a red or brown color. When the fibrin, in its soluble form, is present, it usually coagulates spontaneously on cooling, causing the urine to become gelatinous. The coagulum of fibrin, when pressed between glasses, is generally composed of minute amorphous particles, with a few red blood corpuscles, quite different from the granular mucus corpuscles, for which it might be mistaken without microscopic examination. Bile or purpurine in urine has nearly the same color as when blood is present; hence, unless the blood corpuscles are present, we should apply the tests for the detection of those substances before finally deciding. Purpurine will be dissolved by treat- ing with warm alcohol, or may be precipitated by adding a little warm aqueous solution of urate of ammonia, which on cool- ing will fall down, carrying with it the coloring matter. Bile may be tested by pouring a few drops of urine on a white plate, and adding carefully a drop or two 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 only slight traces of bile are. present, the urine should be con- centrated by evaporation. When semen is present in urine, it may easily be detected under the microscope, by the appearance of minute animalcu- les, always found in the spermatic fluid, and hence called sper- matozoa. They are oval in shape, with long and delicate tails. Traces of albumen may generally be detected in urine contain- ing semen. EXAMINATION OF URINARY DEPOSITS. 183 DIABETIC AND ALBUMINOUS URINE. Albumen may be tested by boiling the suspected urine gently in a test-tube, when it will be coagulated. As, however, a white precipitate results on boiling, from an excess of earthy phosphate, it will be necessary to add a few drops of nitric acid, which will re- dissolve the phosphates but leave the coagulated albumen un- affected. Nitric acid also will coagulate albumen. If both heat and nitric acid throw down a white precipitate from urine in separate portions, there can be no doubt of the presence of albumen. The peculiar casts of urinary tubes found in the urine of patients suffering from Bright' s disease, consist of fibrinous or albuminous matter and entangling'blood-corpuscles, epithelium, and fatty globules. Diabetic Sugar has the same chemical composition as that contained in most kinds of fruit, known as grape sugar. Se- veral tests have been proposed for its detection in urine. Trommer's Test is founded on the circumstance that when a solution of diabetic or grape sugar is boiled with a mixture of potash and sulphate of copper, the oxide of copper contained in the latter is reduced to the state of suboxide, which is pre- cipitated in the form of a reddish-brown or ochre-colored granular powder. Moore's Test is made by mixing a little suspected urine with half its volume of liquor potassse and boiling gently for about five minutes. If sugar is present, the liquid assumes a brown or bistre tint. The Fermentation Test is made by filling a test-tube with the suspected urine, to which a little yeast has been added. The tube is then inverted over a saucer containing some of the urine, and set aside in a warm place for about twenty-four hours. If sugar is present it undergoes the vinous fermenta- tion, by which it becomes converted into alcohol and carbonic 184 THE MICROSCOPIST. acid. The latter rises in the tube and displaces the liquid. If no sugar be present, no fermentation will take place, and no gas will be formed in the tube. Test from the Growth of the Torula. During the process of the vinous fermentation of a liquid containing sugar, a delicate white scum collects on the surface, which when examined with a magnifying power of four or five hundred diameters, will be found to consist of small, oval vesicles, a, Fig. 58, which, in Fig. 58. O i> & % * > fo % . ir*a % the course of a few hours, rapidly change their form, becoming longer and more tubular, and give rise to new vesicles, which shoot out from the parent body, forming an irregular jointed confervoid stem, 6. These again break up into a great num- ber of oval vesicles, which separate, and fall to the bottom, where they may be detected by the microscope. The following tables for facilitating the examination of urine and urinary deposits, are modified from Bowman's Me- dical Chemistry. The reader may also consult the Manuals of Drs. Golding Bird, Griffith, Markwick, and Rees. The works of the latter three gentlemen have been published in Philadel- phia, in one convenient volume. The "Analysis" of Dr. Rees contains also a valuable essay on the treatment of urinary dis- EXAMINATION OF URINARY DEPOSITS. 185 TABLE I. FOR THE CHEMICAL EXAMINATION OF URINARY DEPOSITS. 1. The sediment dissolves when warmed. Urate of Am- monia. 2. Not soluble when warmed, but soluble in acetic acid. Earthy Phosphates. 3. Insoluble in acetic, but soluble in dilute hydrochloric acid. Oxalate of Lime. 4. Insoluble in dilute hydrochloric acid. Purple with nitric acid and ammonia. Uric Acid. If neither of these, it may be, 5. Greenish-yellow deposit, easily diffused on agitation. 6. Ropy and tenacious. Mucus ? 7. Red or brown; not soluble when warmed; the fluid por- tion coagulable by heat and nitric acid. Blood ? 8. Soluble in ammonia; the solution leaving, on evaporation, hexagonal crystals. Cystine f 9. Yellowish sediment, soluble when warmed. Urate of Soda f 10. Ether yields, after agitation, an oily or fatty residue. Fatty Matter. 11. Milky appearance. Chylous Matter. TABLE II. FOR THE EXAMINATION OF THE CLEAR LIQUID PORTION. 1. Crystals with nitric acid. Excess of Urea. 2. Fermentation, or Trommer's test. Sugar. 16* 186 THE MICEOSCOPIST. 3. Precipitate formed on boiling; soluble in nitric acid. Excess of Earthy Phosphates. 4. Precipitate formed on boiling ; insoluble in nitric acid. Albumen. 5. Precipitate formed by nitric acid. Excess of Uric Acid, or Albumen. 6. Concentrated urine yields needle-shaped crystals with hydrochloric acid. Hippuric Acid. If the urine is highly colored, 7. Dark coagulum formed on boiling. Blood ? 8. Red color with hydrochloric acid. Excess of Coloring Matter. 9. Pink precipitate with warm solution of urate of ammonia. Purpurine. 10. Change of color with nitric acid. Biliary Matter. TABLE III. FOR MICROSCOPICEXAMINATION OF DEPOSIT. If Crystalline. 1. Lozenge-shaped, &c. Uric Acid. 2. Stellas, or three-sided prisms (after saturating with am- monia). Triple Phosphate. 3. Octahedra, or dumb-bells. Oxalate of Lime. 4. Rosette-like tables. Cystine. If Amorphous. 5. Soluble when warmed. Urate of Ammonia. 6. Soluble in acetic acid. Phosphate of Lime. 7. Yellowish grains. Urate of JSoda ? EXAMINATION OF URINARY DEPOSITS. 187 8. Round globules with dark edges. Fatty Matter. 9. White and milky. Chylous Matter ? If Organized. 10. Granulated corpuscles, in stringy aggregations. Mucus. 11. Irregularly shaped scales. Epithelium. 12. Detached granulated corpuscles. Pus. 13. Blood-corpuscles. Blood. 14. Spermatozoa. Semen. CHAPTER XIII. ON POLARIZED LIGHT. " IF we transmit/' says Dr. Brewster, " a beam of the sun's light through a circular aperture into a dark room, and if we reflect it from any crystallized or uncrystallized body, or trans- mit it through a thin plate of either of them, it will be re- flected and transmitted in the very same manner and with the same intensity, whether the surface of the body is held above or below the beam, or on the right side or left, or on any other side of it, provided that in all these cases it falls upon the surface in the same manner, or, what amounts to the same thing, the beam of solar light has the same properties on all its ,'ides; and this is true, whether it is white light as directly emitted from the sun, or whether it is red light, or light of any other color. " The same property belongs to light emitted from a candle, Me. or any burning or self-luminous body, and all such light is called common light. A section of such a beam of light will ON POLARIZED LIGHT. 189 be a circle, like A, B, C, D, Fig. 59, and we shall distinguish the section of a beam of common light by a circle with two diameters, A B, CD, at right angles to each other. " If we now allow the same beam of light to fall upon a rhomb of Iceland spar, as in Fig. 60, and examine the two circular beams, o } E e, formed by double refraction, we shall find, " 1. That the beams o, E e, have different properties on dif- ferent sides ; so that each of them differs, in this respest, from the beams of common light. " 2. That the beam o differs from E e in nothing, excepting that the former has the same properties at the sides A' and B' that the latter has at the sides C' and D', as shown in Fig. 59 ; or, in general, that the diameters of the beam, at the extremi- ties of which the beam has similar properties, are at right angles to each other. " These two beams, o, E e, Fig. 60, are therefore said to be polarized, or to be beams of polarized light, because they have sides or poles of different properties. " Now it is a curious fact, that if we cause the two polarized beams, O o, E e, Fig. 60, to be united into one, we obtain a beam which has exactly the sajme properties as the beam A, B, 190 THE MICROSCOPIST. C, D, Fig. 59, of common light. Hence we infer, that a beam of common light consists of two beams of polarized light, whose planes of polarization, or whose diameters of similar properties, are at right angles to one another." There are other means of polarizing light besides that of double refraction, just mentioned. M. Malus discovered, in 1810, that a beam of common light, reflected from glass at an angle of 56, or from water at an angle of 53 became polar- ized. In order to explain the phenomena of polarized light when produced by reflection from glass, let C, D, Fig. 61, represent Fig. 61. T> two tubes, one turning within the other. A, B, are plates of glass capable of turning on their axis, so as to form different angles with the axis of the tube. If a beam of light, r s, from a candle or hole in the window- shutter, fall upon A at the polarizing angle of 56 45', it will be reflected through the tubes, and will fall upon the second plate, B, also at an angle of 56 45'. If, however, this plate be so placed that its plane of reflection is at right angles to the plane of reflection of the first plate, A, the ray of light will not suffer reflection from B, or will be so fainb as to be scarcely visible. If we now turn round the tube, D, carrying the plate, B, without moving the tube C, the reflected ray, E, ON POLARIZED LIGHT. 191 will become brighter and brighter till the tube has been turned round 90, when the plane of reflection from B is coincident with and parallel to that from A. In this position the reflected ray, E is brightest. If the tube be turned again, the light will grow more and more faint, until another 90 are arrived at, when it will again undergo reflection. Thus, changes will take place in every quadrant of 90 until the starting-point is again reached, the ray of light being alternately faint and visible. The same effect will be produced if we cause a ray of light, R, Fig. 62, to pass through bundles of glass plates, A, B, in- clined at the proper angle. If the bundle of plates, B, be placed as [in the figure, the ray s >, polarized by passing through the bundle, A, will be incident on B at the polarizing angle, and not a particle will be reflected, but it will be trans- .mitted, as seen at v w. If B is now turned round its axis, the transmitted light, v w, will gradually dimmish, and more and more light will be reflected by the plates of B, till, after a rotation of 90, the ray, v w, will disappear, and all the light will be reflected. Alternate transmissions and reflections will thus take place in every quadrant, as in the former case. For the ray passing through the tube in Fig. 61, or the ray, s r, in the last figure, we may substitute one of the polarized rays formed by double refraction in a rhomb of Iceland spar, as seen in Fig. 60, or we may employ with even greater ad- vantage the single image prism of Mr. Nicol, who employed a rhomb of calcareous spar divided into two equal portions, in a plane passing through the acute lateral angles, and nearly 192 THE MICROSCOPIST. touching the obtuse solid angles. The cut surfaces having been carefully polished, were then cemented together with Canada balsam, so as to form a rhomb of nearly the same size and shape as it was before cutting. By this arrangement, of the two rays into which a beam of common light would be separated, only one is transmitted, the other being rendered too divergent. Two of these prisms form the usual polarizing apparatus of the microscope, being used in the same manner as the bundles of glass plates, Fig. 62, just described. One of the prisms is adapted to the under surface of the stage, and is called the polarizer ; the other, called the analyzer, is placed above the eye-glass. Dr. Brewster recommends that the analyzing prism be placed immediately behind the object-glass, next the eye, having a rotation independent of the body of the microscope. Another method of polarizing light, is to disperse or absorb one of the oppositely-polarized beams which constitute common light, and leave the other beam polarized in one plane. These effects may be produced by thin plates of agate, tourmaline, &c. Many persons employ a thin plate of tourmaline as an analyzer in place of a Nicol's prism, and if its color be not objectionable, it may be used to advantage, as the field of view is not so much contracted as when a prism is used. A tourmaline of a neutral tint is an excellent analyzer. The splendid colors, and systems of colored rings produced by transmitting polarized light through transparent bodies that possess double refraction, are the most brilliant phenomena that can be exhibited. They were discovered simultaneously by M. Arago and Dr. Brewster. To see these colors : having the polarizing apparatus so placed that no light can be seen through it, place a thin film ofynica or sulphate of lime (between the twentieth and fiftieth ON POLARIZED LIGHT. 193 of an inch thick), so that the polarized beam may pass through it perpendicularly. It should be placed between the polarizer and the analyzer, as on the stage of the microscope. If now the eye is applied to the polarizing apparatus, as before, the surface of the film of sulphate of linie, &c., will be seen covered with the most brilliant colors. If the film be turned round, still keeping it perpendicular to the polarized ray, the colors will become less or more bright, and two positions will be found, at right angles with each other, wherein no colors at all are perceived. If the analyzer be turned round, the film retaining its position, complementary colors will alternate, together with points of invisibility, during each revolution. The colors of the film vary with its thickness, so that by making grooves or lines of various depths, the most beautiful patterns may be produced. Drawings of figures and land- scapes are thus executed, and being mounted between glasses in Canada balsam, are invisible, or nearly so, till exposed to polarized light, when they are seen distinctly, arrayed in most gorgeous colors. Various crystals exhibit, round their axes of double refrac- tion, beautiful systems of colored rings, often intersected by a black cross. Complementary colors may be produced in them by turning round the analyzer. In large crystals, as rhombs of Iceland spar, certain angles must be ground down and polished in order to exhibit the rings. In those crystals having two axes of double refraction, a double system of rin^ will be seen. A transverse section of a prism of nitre will exhibit this phenomenon. The great advantage of employing the microscope in viewing the colors of crystals, &c., by polarized light, arises from the fact that, when crystallized on a slip of glass, many of the small crystals will be arranged with their axes of double re- fraction in the direction of the polarized beam. All such, 17 194 THE MICBOSCOPIST. therefore, will exhibit colors, as will those also in which the thickness of the crystal is not below the proper standard. After the polarizing apparatus is adjusted, as before de- scribed, the crystals properly mounted may be placed on the stage, in the same way as ordinary objects. Some few vege- table structures may be exhibited in the same manner, as the siliceous cuticle of equisetum, starch, &c. Many animal structures, as feathers, slices of quill, horn, &c., are best shown by placing a film of selenite or mica beneath them, by which they become intensely colored. If the film be of unequal thickness, the colors will vary, "The application," says Mr. Quekett, "of this modification of light to the illumination of very minute structures has not yet been fully carried out, but still there is no test of diffe- rences in density between any two or more parts of the same substance that can at all approach it in delicacy. All struc- tures, therefore, belonging either to the animal, vegetable, or mineral kingdom, in which the power of unequal or double refraction is suspected to be present, are those that should es- pecially be investigated by polarized light. Some of the most delicate of the elementary tissues of animals, such as the tubes of nerves, the ultimate fibrillas of muscle, &c., are amongst some of the most striking subjects that may be studied with advantage under this method of illumination." To prepare Crystals for Polarized Light. Pour a few drops of a saturated solution of the salt on a glass slide, gently warm it over a spirit lamp, so^s to evaporate the excess of fluid, taking care not to apply too much heat, lest the water of crystallization be driven off and the salt become opaque. The more slowly the crystallization is effected, the better. The crystals should then be examined, and the best of them mounted, either in the dry way (interposing a cell of paper, ON POLARIZED LIGHT. 195 &c. 7 to preserve them from injury by the pressure of the glass cover), or in Canada balsam. If it be desired to examine the crystals during their formation, the crystallization should be carried on in a glass that is slightly concave. All those crys- tals that are so thin as not to exhibit color, may have color given them by placing a film of mica or selenite under them on the stage of the microscope. According to Mr. Fox Talbot, who first applied the micro- scope to the examination of polarized light, sulphate of copper, crystallized from a solution to which a little nitric ether has been added ; oxalate of chromium and potash, from an aqueous solution ; and borax, crystallized in dilute phosphoric acid, are especially beautiful. CHAPTER XIV. MISCELLANEOUS HINTS TO MIC B SO P I S T S. . ON CLEANING THE GLASSES. " When you clean the eye- glasses (a point of great importance to pure vision), do not remove more than one at a time, and be sure to replace it be- fore you begin another ; by this means you will be sure to preserve the component glasses in their proper places ; recol- lect that if they become intermingled, they will be useless. Keep a piece of well-dusted chamois leather, slightly impreg- nated with some of the finest putty or crocus powder, in a little box to wipe them with for it is of consequence to preserve it from dust and damp ; the former will scratch the glasses, and the latter will prevent you from wiping them clean. As to the object-glasses, endeavor to keep them as clean as possible without wiping, and merely use a camel's-hair pencil to brush them with ; for wiping them hard with anything has always a tendency to destroy their adjustment, unless they are firmly burnished into their cells." Dr. Goring. ON STOPPING FALSE LIGHT IN MICROSCOPES. This is one of the most important requisites in an instrument; for however perfect it may be, if there is the least light reflected from the mountings of the glasses, or within the tubes, the fog and glare produced will materially deteriorate their performance ; it is therefore necessary that all their surfaces be made as sombre as possible. The usual method of effecting this is to cover the parts while hot with a black lacquer, made by mixing lamp- MISCELLANEOUS HINTS TO MICRO SCOPISTS. 197 black in a solution of shell-lac in strong spirits of wine. A more elegant method, and better suited for delicate work, is to wash the surface, previously freed from grease and tarnish, with a solution of platina in nitro-muriatic acid (chloride of plati- num) ; after remaining on the work a few minutes it is wiped off, the surface having assumed a deep brown or black color. If these are not at hand, a strong solution of muriate of ammonia will answer for temporary purposes. Another method of sti- fling false light is by stops or diaphragms in the body of the in- strument ; these have already been referred to. CABINET FOR MICROSCOPIC OBJECTS. The author of " Mi- croscopic Objects" recommends a cabinet with shallow drawers twelve of them occupy a depth of four and a half inches the most convenient width from front to back being six inches. Into these shallow drawers the slides containing the objects are laid flat in double rows. The outer ends of the slides are made to fit into a ledge in the front and back of each drawer. The inner ends of the slides meeting in the middle of the drawer are kept down by a very thin slip of wood covered with velvet. In this way the slides do not shake when the cabinet is moved from place to place ; every object is seen without removal, and no loss of time is occasioned in making a selec- tion. Some persons have their slides arranged edgewise, in boxes made in imitation of books ; the ends of the slides being held by a sort of rack. This sometimes may be convenient, but the other form is preferable. GOADBY'S MANIPULATING Box. This is an exceedingly neat and useful article, represented by Fig. 63. No. 1, repre- sents the box when open, No. 2, a movable tray of peculiar form, and No. 3, the box with No. 2 removed. " No. 1. a. Compartment to receive a bottle, 2 inches square, 3J high, to the top of the stopper, for preserving fluid. I. 198 THE MICROSCOPIST. Space reserved for the spirit lamp. c, c. A shelf of tin, perforat- ed with six holes, to receive three stoppered, two-drachm bottles, for liq. potassse, sulphuric acid, carnphene (or turpentine), and Fig. 63. three glass jars, 2f ths high, Iths diameter, made out of stout glass, without a lip, and fitted with corks, for Canada balsam, prepared asphaltum, lamp-black and gold size. d. A slab of porcelain, 2fths square, resting upon a tin frame, and carried up so as to be flush with the level of all the bottles, and the tray (2), when in its place. Beneath the slab is e, a drawer, 2f ths long, 2i wide, and f ths deep, to hold about three dozen of the smallest slides I use, viz., 2th by f ths. Beneath e is a deep well, which occupies the space from the drawer e to/, another drawer, which runs the whole length of the box, from front to back ; it has the width and depth of e. No. 2. g 1 . This compartment of the tray measures 8 inches long, 2 full wide, li deep. It contains the iron plate, its brass legs, and mahogany stand ; a small cutting-board, kept for thin glass only, measuring 6 inches by 2fths, -Jth thick, fur- MISCELLANEOUS HINTS TO MICRO S C OP I ST S. 199 nished with a guide-board 5 inches long, inch wide, and |th thick, and a gauge, 6 inches long, nearly | ths wide, and fth thick. A card-board box, 2 by If ths, and f ths deep, to hold plates of thin glass; the small brass square, already described; mahogany square, 6 inches by 2J, ith thick; a number of badger' s-hair pencils in handles. g z . Glazier's diamond; scratch do.; marine glue (cane) brush; knife and engraver's tool for cleaning cells ; small glass mules to grind the black cement on the porcelain slab, and sundry glass (dropping and other) tubes. g*. Pill-box with whiting; white wax for thread; cot- ton-wool; sundries. No. 3. h. A fixed tray, 4 inches by 2 J, and fths deep, to contain glass for covers to larger cells. i. A well, 5 by 4 inches, 1 full deep, to hold spare slides of the larger size, with or without cells cemented to them, spare cells, &c. k. A supply of the finest and other varieties of China three twist; pill-box containing small pins, so necessary in dissecting j pill- box containing cells cut in the thinnest glass. Drawer/, con- tains several small palette-knives, in ivory handles, for mixing the cement on the slab ; the blades differ in length from 1 J to 3ith, and from ith to fths at the point; drills for glass and many little things. Below the shelf c c, is a similarly perfo- rated shelf, raised somewhat from the bottom, the design being to grasp the bottles at two points. Should the bottles not be sufficiently high to occupy all the depth allowed for them, they must be raised by a shelf of tin, the intention being, that when the box is closed, everything should be more or less pressed upon and kept in its place. The whole is japanned dead black within, and lustrous black without." BREWSTER'S METHOD OP ILLUMINATING OBJECTS. Con- sidering a perfect microscope as consisting of two parts, viz., an illuminating apparatus, and a magnifying apparatus, Sir D. Brewster states, that it is of more consequence that the illumi- 200 THE MICROSCOPIST. nating apparatus should be perfect, than that the magnifying one should be so ; and the essential part of his method consists in this : That the rays which form the illuminating image or disk shall have their foci exactly on the part of the microscopic object to be observed, so that the illuminating rays may radiate as it were from the object, as if it were luminous. Now this can only be well attained by illuminating with a single lens, or a system of lenses, without spherical or chromatic aberra- tion, whose focal length, either real or equivalent, is less than the focal length of the object-glass of the microscope. The smaller the focal length of the illuminating lens, or system of lenses, the more completely do we secure the condition, that the illuminating rays shall not come to a focus, either before they reach the object, or after they have passed it. MODE or OBTAINING THE WHEEL ANIMALCULE (Vortir cella fotatorla). '" Early in the spring I fill a three-gallon jug with pure rain-water (not butt-water, because it contains the larvae of the great tribe). This quantity more than suffices to fill a half-pint mug, and to keep it at the same level during the season. I then tie up a small portion of hay, about the size of the smallest joint of the little finger, trimming it so that it may not occupy too much room in the mug, and place it in the water ; or about the same quantity of green sage leaves, also tied and trimmed. About every ten days I remove the decay- ed portion with a piece of wire, and substitute a fresh supply. A much greater number of animalcules are raised by the sage leaves ; but I have sometimes been obliged to discontinue the use of it, on account of its producing mouldiness. I take them out with an ear-picker, scraping up the sides of the mug near the surface (including the dirt which adheres to them by the tail), or under the hay or sage/' J. Ford. SUBSTITUTE FOR THE CONCAVE SPECULUM. Mr. G-. Jack- son employs a plano-convex lens of about two inches in diame- MISCELLANEOUS HINTS TO M I CRO SCOPI S T S. 201 ter, and of four and a half inches focus, silvered on the plane slide, and backed with a plate of brass. This lens, when so treated, becomes a reflector of about two and a quarter inches focus, and forms one of the best instruments that can be desir- ed for throwing light upon an object viewed as opaque. We have used such arrangement for some time in place of the con- cave mirror, and deemed it peculiar to ourselves till reading an account of the above. APPARATUS TO PREVENT THE EVAPORATION OP LIQUIDS UNDER THE MICROSCOPE. Vapors arising from the liquids under observation would, by condensing on the under surface of the object-glass, form there round drops, which act as so many lenses, and which, arresting the rays of light in their progress, would scatter them in every direction, and thus com- pletely destroy the image before it could reach the object-glass. This effect takes place not only when the temperature of the liquid is raised by the application of heat, either directly or in consequence of chemical action, but also when, in studying any body by the microscope, a fuming acid is used, such as the hydrochloric. This inconvenience is prevented by en- closing the frame of the object-glass in a small glass tube, shut at one end, whose inner surface is closely applied to the surface of the object-glass. This end is then plunged into the liquid, which is thus prevented from either beclouding the surface of the lens or finding its way into the interior of the microscope and there producing the same effect. RaspaiVs Organic Chemistry. DROPPING TUBES, for placing on the object-holder or slide any reagent whose action is to be examined, may be easily made by softening a piece of glass tube in the flame of a lamp, and drawing it out till it becomes capillary, after which it may be broken to a convenient length. Fishing- tubes for animal- may also be made in the same way. INDEX. PACK Achromatic object-glasses, their invention an epoch in histology, 18 description of, ... 34 comparison of different makers, 38 Animal tissues, to be examined when fresh, . . .17 on procuring, . . . . 81 Accessory instruments, . ..... 41 Animalcules cage, ...... 37, 49 Asphaltum cement, . . . ; . . 60 Agate, ....... 67 Algse, . 77 Aphides, ....... 90 Acari, . . . . . . . .90 Anatomical preparations, ..... 94 Areolar tissue, ....... 103 Artificial star, as a test object, .... Ill Angle of aperture, explained, ..... 112 Arm rests, ....... 120 Albuminous urine, . . . . . 170, 183 Alkaline salts in urine, . . . . . 173 Advantage of polarized light in examination, . . . 193 Apparatus to prevent evaporation, .... 201 B. Bog iron ore, from infusoria, . . . . .14 Borelli, his observations on pus, &c., . . . 15 Blood corpuscles, . . . . . .95 204 INDEX. PAGE Blood disks of siren, . . . . . .. 95 Bone, . , . . . . . . ' . --ijdr Basement membrane, ..... 104, 131 Bat's hair, . . . . . . .114 Branchial cartilage of tadpole, .... 135 Blood in urine, ...... 169,181 Bile in urine, ...... 182 Brewster's mode of illuminating objects, . . . 199 C. Causes of error in observation, . . . . . , 15 Coal beds, from vegetation, . . . . .14 Coddington lens, ...... 29 Compound microscope, . . . . . .31 defects of the common, . . 33 improvements in the, . . .33 mechanical conveniences necessary to the, 35 forms of the, . . . .36 most celebrated makers of the, . 36, 38 Smith and Beck's, . . .36 efforts to reduce the price of the, . 38 Condenser, . . . . . . 41, 53 for oblique illumination, ... 42 Condensing (or bull's eye) lens, . . . . 44, 52 Camera lucida, . . .' . . 37, 47 Compressorium, ....... 50 Cook's preserving fluid, . . - r ,- ; . "" ~ ' 56 Cooper's preserving fluid, ^;. 56 Cells for mounting, ...... .,.>-. 59 Cements, ........ 60 Canada balsam cement, ..... 61 Charring vegetable matters, . . . . .61 Carbonate of lime, ...... 67 Crystallization of salts, ...... 67 water, ..... 68 Cuticles, ...... ,..;. ,; . 69 Cellular tissues, , . 70 INDEX. 205 PAGE Charcoal, . . . . ..,,. 1 . 73 Circulation in vegetables, ..... 78 Corals, ...... i ,,^ t , . 86 Circulation of blood, ..... 96 Capillaries, their functions, . . . ... 106 of skin, .... -~ . 100, 109 of mucous membrane, . . .105,109,167 Crystalline lens in fish, . . . . . 101 Ciliary processes of the eye, . . . .' . 101 movement, . . . . . . 105 Chromatic aberration, ...... 33 mode of observing, . . . 110 Circulatory system of insects, . . . . --;' 126 Chemical constitution of organized bodies, . . . 130 Cell-growth in a meliceritous tumor, . . , - -* 137 Classification of animal tissues, .... 136 malignant growths, . . . .142 Carcinoma, ....... 143 Chemico -gelatinous injection by Dr. Goadby, . . .164 Cystine in urine, . . . . . . 179 Colors exhibited by polarized light, . . . .192 Cleaning the glasses of microscopes, . . . 196 Cabinet for microscopic objects, . . . . .197 D. 9- Dissecting microscope of Mr. Slack, ... 27 Dark wells, . . . . . 38 Diaphragm, . . . . . . 37, 41, 51, 53 Deut-ioduret of mercury, . . . . .68 Dissecting needles, ...... 119 troughs, . . . . v%, . 120 Digestive system of insects, ..... 125 Development of cells, . . . ... 131 animal tissues, .... 134 Diabetic urine, ...... 170, 183 18 206 INDEX. E. PAGBr Erector, . . . . . . " ."*' 44 Entozoon folliculorum, , . . 91 Epithelium, ...... '' 1 104 Examination of morbid structure, . . r * >v . 139 its importance, . , 141 Encephaloid, ....... 146 Earthy phosphates in urine. . . . 169,171,174 Eyes of animals, . . . . . . V 101 F. Fossil remains determined by the microscope, . . 14 Fontana, histological observations of, . . . .17 Frog plate, , . . . . . . 47 Fishing tubes, . . . . . . 49, 201 Fossil wood, ....... 73 Ferns, . . . . . . . . * 77 Fibrous and areolar tissue, . . . . . 103 Forms of nuclei, . . . . . . .133 Form of fibrous tumor, ..... 141 G. Geology, use of microscope in, . . . . .13 Goadby's fluids, ...... 57 manipulating box, . . . <: . 197 Gum mastich cement, . , J V.S . '-*. c 60 Glycerine, ...... V 56 H. Histology, created by the microscope, . . ?>** ^ II ewson on the blood globules, . . . .-*./ .-, : 17 Herschell's doublets, . . . . t,^ & 29 Holland's triplet, . , . . .31 Huygenian eye-piece, . 35 Hairs, down, &c., of plants, . . . , .. ,*, .. 73 INDEX. 207 PAGE Hard tissues, ...... 76 Hair of animals, . . . . . _ .^ 93 Horn, hoofs, quills, &c., . . . . . ;,..*,. 94 Human blood, . . . . . . 94 Hair of Dermestes, . . . . . , .: . ; 114 Hippuric acid, . . . . . ; "'" - 172 I. Importance of the microscope to zoology, . ' . 14 Inorganic objects, . . . . . .67 Illuminating lamp, ... ... 45, 52 Iron pyrites, . . . . . 68 Infusoria, classification of, . . . . . 81 on procuring, . . . . .' ~ . 83 to observe the structure of, . . *\ 85 fossil, . . . . . 85 Insects, antenna) of, . . . . . . 86 eggs, . . . . 87 elytra, . . . . . .88 eyes, . . . . . \ '. t . 88 feet, . . . . . . 89 hairs, . . . . . 89 mouths, &c., . . . . -...- 90 parasitic, . . $'- :>,# . 90 trachea, . . . . . . 91 stings, ovipositors, &c., . . . .91 internal anatomy of, . . . .123 Injected papillae of skin, .... 99, 109 preparations, .... . v -- 106 Instruments for minute dissection, . . . .118 Internal anatomy of insects, . 123 Injecting materials, . >>* . . . 158, 161, 163 Instrument for diagnosis of tumors, . . r*f ;-" 1^8 Injection of the lymphatics, . . ' . . 167 J. Japanner's gold size, ..... 60 208 INDEX. PAGE Riestein, . . . . . . . -^ - 170 L. Lenses, different forms and effects of, . . 22 simple mode of making, . . . .28 imperfections in, ..... 29 Lewenhoeck, his discoveries, . . . . .16 Lieberkuhn, his anatomical researches, . . . 17 concave reflector, so called, . . .46 Lamp-black cement, ...... 61 Lichens and fungi, ...... 77 Loaded corks, . . . . . . 120 Lepisma saccharina, . . . . . .115 M. Malpighi, microscopic researches of, . . . [15 Modern observers, . . . . . .19 Medico-legal inquiries with the microscope, . . 21 Micrometer eye-piece, ...... 35 stage, ...... 48 Magnifying powers, hints respecting, . . . .51 table of, . . . .; 23 to obtain the power of a compound micro- scope, . . . . .48 Mirror, use of the, . . . . . * 52 Management of the light, . . . . ,52 Mounting transparent objects, .... 55 in the dry way, . . 55, 56, 63 in fluid, . . . 58 in balsam, . . . 61 Marine glue, . . .. . . .1 j&^ 60 Mounting cellular structures, .... y. 62 opaque objects, ..... 64 crystals for polarized light, . . . 66, 194 Mosses, . . . . . , * ; 76 INDEX. 209 PAGE Muscular fibre, . . . . . . .101 Mucous membrane, . . . . . 104 Mouse hair, . . . . ... .114 Morpho Menelaus, . . . . . . 115 Muscular system of insects, .... *. 128 Morphology of pathological fluids, . . . . s 149 Method of injection, by Ruysch, . . . .168 Rauby, . . ... 163 Monro, . . . . . 163 Professor Breschet, . f . 163 M. Doyere, . . . .163 Dr. Goddard, . . . 163, 166 Mucus in urine, ....... 181 N. Nervous structure, examination of, . . . . 102 Nerves and capillaries of muscle, ..... 102 Nervous system of insects, . . . . . 126 0. Organic remains in limestone, . . . . .14 Optical illusion to be guarded against, . . . 17 Opaque objects, mounting of, . . . ' 64 how viewed, .... 53 Mr. Brooke's mode of viewing, . . 46 Oolites, 68 Organic fibres, . . . . . . - . 77 Oxalate of lime in urine, . . . . 169,176,185 P. Polarizing apparatus, ...... 43 Preparation of glass slides, ..... 56, 58 Preserving fluids, . . . . . * 56 Pollen, / 74 Pigment cells of skin, . . . . . .100 of the eye, . . . . . 101 210 INDEX. PAGE Pontia brassica, . . . . . ...* .116 Podura plumbea, . . . . >. '..*: H6 Proximate principles, . . . . . 130 Primary form of organic matter, . . < $'4 ' 130 Pus in urine, ..... ..- 170,181 distinction between it and mucus, . . . 139 Polarization of light, . . .' . > 188 Q. Qualifications of a microscopist, . . . .;*' 18 R. Religious sentiment, microscope conducive to, . . . 13 Reflecting microscope superseded, .... 39 a curious form of, . . . .39 Rules for microscopic observations, ... 51 Raphides, . . ; ' ''' . .76 Retina of the eye, ...... 101 Respiratory system of insects, ..... 123 S. Simple microscopes, construction of, . ? :-.j, . .,-. 23 magnifying powers of, . . 23 mode of mounting, . . > - 23 form of, for opaque objects, . ..26 Stanhope lens, . . . . .'*. 29 Silver cup or Lieberkuhn, . . ..... '. 37,46 Side reflector, . . . . . 37, 46 Stage micrometer, ...... 48 Size of glass for mounting, . ^ . . . 55 Sealing-wax varnish, . \ . . ' * * . 60 Sand, ...... . 68 Sections of granite, &c., . . . . . 68 coal, . . . , . '. . 68 wood, . .' . . . ' r . 72 Siliceous cuticles, .... . - . 73 INDEX. 211 PAGE Starch, . . . - A . . . . . . 74 Seeds, ; .; ' -.- .. .*., ,' r . > ^ , *;-, 76 Sponges, . . . ,1. -. "'..$& - * 86 Shells of mollusca, . . .'& ...,._ .. 91 Scales of fish, . . . . . , .. * 92 Skin, ...... v > ,* 99 Spherical aberration, ..... 33, J10 Scales of insects, . . . . . . 115 Shells of infusoria, . . . . . 85,116 Swammerdam's scissors, . . . . . 118 mode of dissection, .... 121 Secondary organic compounds, . . . . 130 Scrofulous growths, ...... 142 Syringe for minute injection, . . :< .'" . . . 69 Vascular tissue in plants, . . . . .72 Vitality and electricity not identical, . . . 108 Valentin's knife, . ;<' . 'I' . -. . 119 Vital principle, theories respecting the, . . . 106, 129 W. Withering's Botanical Microscope, . . . .23 Wilson's Pocket Microscope, .... 24 Wollaston's doublet, ...... 80 condenser, ..... 42 Watch-glasses useful, ...... 49 White fibrous tissue, . . . . . 103 Wheel animalculee, mode of obtaining, .... 200 Y. Yellow fibrous tissue, . . . . . 103 Z. Zoophytes, ....... 86 THE END. LINDSAY & BLAKISTON'S PUBLICATIONS. MORFIT'S cllEMICAL AND PHARM/ECEU- TICAL MANIPULATIONS, WITH litateft nni 'tenti-tim 3ltastnitnra0. A MANUAL OF THE MECHANICAL AND CHEMICO-MECHANICAL OPERATIONS OF THE LABORATORY- CONTAINING A COMPLETE DESCRIPTION OF THE MOST APPROVED APPARATUS, WITH IS- 8TRUCTION8 AS TO THEIR APPLICATION AND MANAGEMENT, BOTH IN THK MANUFACTURING PROCESS AND IN THE MORE EXACT DETAILS OF ANALYSIS AND ACCURATE RESEARCH. BIT CAlMCFBHXiIi MORI* IT, Practical and Analytical Chemist ; Author of "Applied Chemistry," &c. Ac. ASSISTED BY ALEXANDER MUCKLE, Chemical Assistant in Professor Booth's Laboratory. IN ONE VOLUME, OCTAVO. Extract of a Letter from Prof. J. C. Booth, Practical ana. Analytical Chemist. "I regard it as a very valuable addition to a Chemical Library, whether to that of an experimental or manufacturing' chemist ; for, while the business of the former is wholly experimental research, the latter is frequently forced to enter into the same field, in order to improve his processes. Although I have been a witness of the author's untiring in- dustry in preparing this work, yet, upon examining it in its present state, I am surprised to find it so complete in all its parts. I know that there is n large amount of original matter contained in it, the result of the author's observation and experience ; and that which has been derived from other sources, has been judiciously and harmoniously culled from a very extensive Chemical Library. I therefore think that every one connected with Chemistry, in any of its numerous departments, should have a copy of this work in his library. I intend using it freely in my course of instruction in Experimental Chemistry, and shall recommend it to my students." This work is one that ought to be in the hands of every student of Pharmacy and Chemistry. It contains a variety and amount of information for which he will seek in vain in any of the professed treatises on Chemistry. The author has had in his mind the admirable treatise of Professor Farraday, and has given in a condensed form nearly all that is valuable for ordinary use in that work, besides much original matter, and much collected from other sources all of which has been rendered far more useful and intelli- gible by the aid of excellent illustrations. American Journal of Pharmacy. To every one who desires to become familiar with the operations of the laboratory,