THE TANNINS 
 
 HENRY TRIMBLE 
 
■ran? bhe £ibra?y of Trof JMAfo/scj, 
 
 [ }9M/2^0^e^c^ 
 
 F. EL HERRICK. 
 
PHILADELPHIA: 
 
 J. B. LIPPINCOTT COMPANY. 
 1892 . 
 
Copyright, 1891, by Henry Trimble. 
 
 Printed by J. B. Lippincott Company, Philadelphia. 
 
 THE GETTY CENTER 
 LIBRARY 
 
PREFACE. 
 
 The title of this monograph might well have been 
 “A Century of Tannin,” as just about one hundred 
 years have elapsed since tannin first became recog¬ 
 nized as a distinct substance, or class of substances, as 
 we now express it. To emphasize this idea of a class 
 of substances the present title was selected. 
 
 About twelve years ago the author commenced 
 to collect a portion of the literature on the subject, 
 especially that referring to the astringent value of 
 certain tannin-bearing materials, with the methods 
 involved in their estimation. He found, however, the 
 task rapidly assuming such formidable proportions 
 that only by beginning with the history and system¬ 
 atically pursuing the subject through its various phases 
 to an ending, with a complete index to the literature, 
 could he hope to reduce the many published inconsist¬ 
 encies and contradictions to a condition that would be 
 available to himself as well as to others. 
 
 The taking of notes and references has been persist¬ 
 ently carried on, especially during the past five years, 
 until it is now thought best to give to the public the 
 work on the general subject, with gallotannic acid, and 
 the index to the literature, leaving for a subsequent 
 volume the remaining individual tannins, with such 
 further additions to the index as it may be found 
 possible to collect. 
 
 It has been the constant effort of the author to make 
 
 3 
 
4 
 
 PREFACE. 
 
 this volume something more than a mere compilation 
 of others’ work, therefore some of his own experience 
 has been incorporated which is here published for the 
 first time, and this will be kept constantly in mind 
 during the further contributions on the subject. 
 
 The tannins occupy a part of the border-land in sci¬ 
 ence between botany and chemistry, which fact has 
 added to the bulk of the literary index as well as to 
 the difficulties of collecting it. 
 
 However, by the aid of the many complete sets of 
 valuable foreign chemical periodicals recently acquired 
 by the library of the Franklin Institute, and also 
 through constant access to the library of the Phila¬ 
 delphia College of Pharmacy, it has been possible to 
 take from the original sources all but about five per 
 cent, of the titles given. Such references as could not 
 be so consulted were taken from the most available 
 source, and, if possible, in the same language as the 
 original. 
 
 It is with the hope that information will be received 
 from others interested in the subject, which will assist 
 in making the index more complete, that it is issued at 
 the present time. 
 
 Much valuable assistance has already been received 
 by the author, especially from those having desirable 
 private libraries, for which he hereby tenders his sincere 
 thanks. 
 
 Philadelphia, November 13, 1891. 
 
CONTENTS. 
 
 PART I. 
 
 PAGE 
 
 General Description or the Tannins . 7 
 
 Section I.—The Discovery of the Tannins. 9-16 
 
 Section II.—General Characters.17-30 
 
 Section III.— The Detection and Estimation of the 
 Tannins .31-51 
 
 PART II. 
 
 Gallotannic Acid. 53 
 
 Section I.—Sources.55-64 
 
 Section II.—History.65-77 
 
 Section III.—The Preparation and Purification of 
 
 Tannic Acid .78-87 
 
 Section IV.—The Properties of Tannic Acid . . . 88-93 
 Section V.—The Composition and Constitution of 
 
 Tannic Acid.94-99 
 
 An Index to the Literature of the Tannins . . 101 
 
 Index of Authors .103-108 
 
 Index of Titles with Authors and Sources 109-162 
 List of Books containing Notable Chapters 
 on the Tannins .163-165 
 
 5 
 

THE TANNINS. 
 
 SECTION I. 
 
 THE DISCOVERY OF THE TANNINS. 
 
 The history of tannin as a proximate principle takes 
 its beginning in France during the period between 1790 
 and 1800. Previous to that time the histories of leather, 
 galls, and oak-bark are our only sources of information 
 regarding the development which led to the discovery 
 of tannin. 
 
 Great discoveries are rarely made without some 
 warning; in reviewing their origin we see that they 
 have had a gradual birth, and the exact date which in¬ 
 dicates the beginning of their existence cannot be deter¬ 
 mined. In these evolutions of a discovery there are 
 sometimes periods of comparative inactivity, succeeded 
 by sudden and great advances. The history ot tannin 
 has not been an exception to the rule of gradual dis¬ 
 covery, for we find among the earlier writers on the 
 subject a disposition to attribute the astringency of galls 
 and oak-bark to some peculiar principle, which, how¬ 
 ever, they did not separate or name. 
 
 Dr. William Lewis, in his “ Philosophical Com- 
 of the Arts,'London, 1763,” calls attention to 
 
 9 
 
 merce 
 
10 
 
 THE TANNINS. 
 
 the presence of a substance in certain vegetable infu¬ 
 sions, which, when mixed with “green vitriol,” pro¬ 
 duces “a deep black liquor, of most extensive use for 
 dyeing and staining black. The power by which they 
 produce this blackness and their astringency, or that 
 by which they contract an animal fibre, seem to de¬ 
 pend upon one and the same principle, and to be pro¬ 
 portional to one another.” “ Of the properties of this 
 colouring and astringent matter, little more is known 
 than that it is dissolved and extracted from the subject 
 both by water and spirit of wine, and that it does not 
 exhale in the evaporation of the liquors by heat.” 
 
 English writers on tannin usually ascribe to Dr. 
 Lewis the honor of having a part in its discovery, but 
 further than for writing the above quotation of facts, 
 which were well known before his time, it is unreason¬ 
 able to give him credit. 
 
 He was followed by other investigators, chiefly on 
 galls and oak-bark, especially in the relation of the 
 latter to tanning, which gradually led to the discovery 
 of gallic acid by Scheele in 1786. 
 
 Diz6 in 1791 repeated Scheele’s experiments on galls, 
 obtaining similar results; but he went further, and 
 separated what he called a resinous substance by means 
 of ether. It was unchanged on exposure to air, pos¬ 
 sessed an herbaceous taste, dissolved readily in water, 
 and this solution formed a white precipitate with sul¬ 
 phuric acid. 
 
 Two years later, in 1793, Deyeux, a French chemist 
 and apothecary, published a memoir giving the results 
 of an elaborate series of experiments, preceded by a 
 description of the Aleppo and some other varieties of 
 
THE DISCOVERY OF THE TANNINS. 
 
 11 
 
 galls. It is then stated that, “ in the number of prop¬ 
 erties which appertain to nutgalls, there is one, very 
 remarkable, which has always fixed the attention of 
 chemists,—namely, the precipitate of the solution with 
 the solution of iron salts. This has been attributed to 
 an astringent body ,—‘principe astringent 
 
 “ Among those who have occupied themselves with 
 this subject may be mentioned Cartheuser, Bouelle, 
 Macquer, Monnet, and Giannoti; but it is principally 
 the academicians of Dijon, likewise Scheele, Berthellot, 
 Fourcroy, and others, to whom we are indebted for the 
 positive knowledge of this singular substance. They 
 have demonstrated the existence of a peculiar acid which 
 they have named gallic acid. This has made desirable 
 a knowledge of the other constituents, and it is this 
 which is made the subject of the following memoir.” 
 
 The record of the experiments was made under eight 
 sections, as follows: 
 
 1. “ The action of water on nutgalls. 
 
 2. “ The action of alkalies on the infusion and de¬ 
 coction of nutgalls. 
 
 3. “ The action of alcohol and ether on nutgalls. 
 
 4. “ Distillation of nutgalls with water. 
 
 5. “ Dry distillation of nutgalls. 
 
 6. “ Examination of the gallic acid which sublimes 
 during the distillation of nutgalls. 
 
 7. u Examination ot the precipitate which forms 
 when nutgalls, their solution, and gallic acid are added 
 to ferrous sulphate. 
 
 8. “ Recapitulation.” 
 
 This last section may be briefly stated as follows: 
 
 Nutgalls are composed of (1) a true extractive mat- 
 
12 
 
 THE TANNINS. 
 
 ter, (2) a peculiar resin, (3) a green coloring-matter, (4) 
 gallic acid, (5) ligneous tissue. “ All of these bodies 
 except the ligneous tissue are in strong combination, 
 resulting in a body soluble in alcohol, ether, and water. 
 It is to this body entire and not to any principle in 
 particular that the astringency belongs, since none of 
 these compounds alone possess it.” 
 
 In terminating this memoir the author expressed the 
 hope that others would repeat his experiments and 
 rectify his errors. 
 
 It has been quoted at some length because it is a 
 record of experiments that for ingenuity and accurate 
 reasoning would do credit to any investigator at the 
 present time. The author was wrong in some of his 
 deductions, but, when we consider that then all was 
 darkness where now we have some light, it may not be 
 far wrong to say that he came much nearer the truth 
 than does many a one in our day when examining a 
 new substance. 
 
 It is due Deyeux to say that he discovered tannin 
 when he exhausted nutgalls with ether and described 
 the product as a u refined dry and friable extract.’ 
 On account of the gallic acid, he overlooked the possi¬ 
 bility of there being a still more important substance 
 present. All previous investigators had pointed so 
 strongly to gallic acid as the principal constituent that, 
 notwithstanding he found what he named a peculiar 
 resin to be present in great abundance, he was unable 
 or unwilling to realize it. Finally, he failed to distin¬ 
 guish between gallic and pyrogallic acids, but others 
 also had failed to detect that difference. 
 
 We find at this time that the desire to improve the 
 
THE DISCOVERY OF THE TANNINS. 
 
 13 
 
 process of tanning was the great incentive which led to 
 a more exact knowledge of tannin. One of the chief 
 objects in view was to shorten the process, and the idea 
 of extracting the oak-bark or tan with water is usually 
 attributed to Seguin, but previous to his patent was the 
 suggestion of Macbride in 1795 to extract the bark 
 with lime-water, and that of Anthony Fay to make an 
 extract by boiling the tan with water in the proportion 
 of one pound of the former to three gallons of the lat¬ 
 ter. This extract, or ooze, as he termed it, was to be’ 
 weakened with water and used for tanning, which it 
 accomplished in one-half the time occupied by the 
 methods then in use. Fay’s patent was dated January 
 17, 1790, although not published until 1796. Seguin’s 
 patent appears to have been dated in France in 1795 
 and in England in 1796, in the latter case under the 
 name of William Desmond. 
 
 To afford an understanding of what bearing these 
 patents, especially Seguin’s, had on the discovery of 
 tannin, it will be necessary to state that previous to his 
 investigations the process of tanning was not supposed 
 to be one of a combination of tannin with animal 
 membrane, but simply a physical process in which the 
 astringent property of the bark caused the hide to 
 shrivel, harden, and become non-putrescible; therefore, 
 when Seguin reasoned from his experiments, which 
 were chiefly conducted on quite a large scale in the 
 tanyard, that there was a principle present in oak-bark 
 which combined with hide to form leather, he was 
 given the credit of discovering tannin, although it had 
 previously been separated and recognized as a distinct 
 substance by both Diz6 and Deyeux. 
 
14 
 
 THE TANNINS. 
 
 Seguin’s conclusions were strengthened by the fact 
 that, when he boiled hide with water and added to the 
 clear cold liquid an infusion of oak-bark, he obtained 
 a light-colored precipitate, which was insoluble in hot 
 or cold water and became dark on exposure to light. 
 
 We derive our knowledge of Seguin’s experiments 
 from the report of a committee appointed to examine 
 his process; after some months’ investigation, during 
 which time a hundred or more hides were tanned and 
 the committee wore shoes made of the leather, a satis¬ 
 factory report was made and published. The commit¬ 
 tee consisted of the citizens Lelievre and Pelletier. 
 
 Seguin’s method of preparing the liquor was some¬ 
 what ditferent from that of Fay. The latter, it will be 
 remembered, boiled together the bark and water, while 
 the former poured the liquor from one lot of ground 
 bark to another until it reached a strength of from 10° 
 to 12°. The advantage claimed for this form of the 
 tanning material was that it could be transported, and, 
 as the committee feared the early extinction of forests 
 in France, they suggested that such an extract could be 
 made in America. 
 
 The first separation of tannin in a pure condition 
 was accomplished by Proust in 1798. He added a so¬ 
 lution of stannous chloride to a decoction of galls, and 
 produced an abundant yellow precipitate, which he 
 stated to be a combination of the tanning principle 
 with tin and free from gallic acid. The precipitate 
 mixed with water and treated with hydrogen sulphide 
 was decomposed, forming a sulphide of the metal, 
 which precipitated, while the astringent principle re¬ 
 mained in solution. After removing the sulphide by 
 
THE DISCOVERY OF THE TANNINS. 15 
 
 filtration, the solution was evaporated in a silver basin, 
 yielding a deep-brown, friable residue, which possessed 
 the characteristic odor of the astringent principle. It 
 had a vitreous fracture and did not attract moisture 
 from the air. The taste was strongly astringent, and 
 it completely dissolved in water and alcohol. The so¬ 
 lution of this extract added to a solution of glue formed 
 a magma which possessed the elastic properties of the 
 gluten of flour, was perfectly insoluble in hot water, 
 and was not susceptible of putrefaction. This the 
 author believed to be the secret of Seguin’s preser¬ 
 vation of leather. The remainder of his interesting 
 memoir was devoted to the effects of tannin and gallic 
 acid on ferrous and ferric salts. He also pointed out 
 the fact that the juice of sumac gave the same reaction 
 as this compound from galls. 
 
 By these four investigators the existence of tannin 
 was completely established, and gallic acid became of 
 secondary importance as a constituent of galls and in 
 tanning. It may be briefly stated that Dize first indi¬ 
 cated the existence of tannin and prepared it in an im¬ 
 pure state, Deyeux prepared it in considerable quantity 
 and recognized it as one of the important constituents 
 of galls, Seguin considered it the tanning principle and 
 put the knowledge of its existence to practical appli¬ 
 cation, and Proust first prepared it in an almost pure 
 state. 
 
 In 1801, Karsten reviewed the history of tannin, and 
 attributed the discovery wholly to Seguin, although he 
 spoke highly of Proust’s work. It is very probable 
 that his credit to Seguin was on account of the great 
 practical importance of the latter’s invention, which 
 
16 
 
 THE TANNINS. 
 
 gave it extensive publicity, while the more scientific 
 works of Diz6 and Deyeux were overlooked. 
 
 In 1802, Proust wrote another memoir on tannin, in 
 which he concluded that there were many different 
 kinds of tannin in different plants. This appears to be 
 the first statement of what lias since proved to be a most 
 important principle in the study of the tannins, and 
 with this work of Proust the history of the discovery 
 of tannin may well be closed, and further historical 
 considerations taken up under the individual members 
 of the class. 
 
SECTION II. 
 
 GENERAL CHARACTERS. 
 
 The terms “ tannin” and “ tannic acid” are used 
 indiscriminately by many writers, while others employ 
 the term “ tannic acid” to indicate the whole series and 
 “ tannin” to denote the product from oak-galls. It, 
 however, appears more rational to apply the term 
 u tannic acid” to the product from galls, since it is an 
 acid when pure, and to use the term “ tannin” to desig¬ 
 nate the whole class of astringent substances, many of 
 which are glucosides, and many more hold an un¬ 
 known position among the chemical compounds. Thus 
 u tannic acid” will agree with the German gerbs&ure 
 and the French acide tannique, and “tannin” with the 
 German gerbstoff and the French tannin, although many 
 writers in those languages have also confused the respec¬ 
 tive terms. There is no objection to the use of a more 
 exact designation by prefixing the source of the com¬ 
 pound, as gallotannic acid to the product from galls, 
 sumaetannic acid to that from sumac, catechutannin to 
 that from catechu, etc. In the following pages, there¬ 
 fore, the term “tannin” will be applied to the whole class 
 of astringents, while the compound from galls, as well as 
 those from other sources where they have been shown 
 to be chemically and physically identical with it, will 
 be designated by “ tannic acid.” In both cases a prefix 
 indicating the source will be applied when necessary. 
 
 2* 17 
 
18 
 
 THE TANNINS. 
 
 The tannins may be defined as a class of amorphous, 
 astringent, vegetable substances, the members of which 
 produce a blue or green color and precipitate with salts 
 of iron, and with animal membrane form an insoluble 
 and imputrescible compound called leather. 
 
 The tannins are widely distributed throughout the 
 vegetable kingdom. The richest deposit appears to be 
 in galls, of which they comprise from twenty-five to 
 seventy-five per cent., according to the variety. The 
 next most abundant source is the inner bark of certain 
 trees, notably of the oak species; they are also found 
 in leaves, unripe fruits, woods, and some buds and 
 flowers, but rarely and in small quantity in seeds. 
 
 Many theories have been advanced by different in¬ 
 vestigators to explain the uses and method of forma¬ 
 tion of the tannins in plants. It has been observed 
 that starch is always present with tannin in barks; 
 that in many respects the tannins resemble the resins : 
 the members of both classes, when heated with potas¬ 
 sium hydrate, yield the same or similar products of 
 decomposition, and, further, when seeds which are free 
 from tannin germinate, it may then be detected. It 
 has been found that the amount of tannin in a plant 
 varies greatly with the time of year, and in some cases 
 changes with the variation in the amount of starch 
 present, as shown by Peacock in Heucliera Ameri¬ 
 cana. He determined the amount of tannin to be 
 greatest in October and least in May, while the starch 
 
 was greatest in March. In Geranium maculatum it has 
 © 
 
 been found by the author that the tannin is present in 
 largest amount in April, just before the plant blooms, 
 and rapidly decreases until it reaches a minimum in 
 
GENERAL CHARACTERS. 
 
 19 
 
 October, thus pointing to the possibility of its being 
 a storage material to assist the plant in blooming and 
 perfecting its seed. 
 
 The questions which naturally arise from a consid¬ 
 eration of the various facts are, Do the tannins result 
 from the decomposition of starch? Are they closely 
 related to the resins? Are they a reserve material, or 
 simply a useless by-product? These problems remain 
 to be worked out, and the answers may be found to 
 vary with the kind of tannin. For instance, gallotan- 
 nic acid is simply a morbid deposition of the compound 
 resulting from the sting of an insect, while the other 
 tannins vary according to the circumstances under 
 which they have been formed. 
 
 Probably the most recent contribution to this subject, 
 and one established on many experiments, is the mono¬ 
 graph of Kraus, who has established some facts con¬ 
 cerning the formation of tannin, but has not offered a 
 solution of the various problems. He considered the 
 tannins of different origin to be physiologically alike. 
 This was stated soon after by Reinitzer to be incorrect. 
 Kraus further found that light and carbon dioxide are 
 essential agents of the formation of tannin in leaves. 
 Leaves which are not green are not capable of producing 
 tannin. The outer leaves of a plant, exposed to direct 
 sunlight, contain more tannin than the inner leaves. It 
 is not a product of the assimilation of chlorophyll grains; 
 the oak, willow, and alder assimilate in dull weather 
 without increasing in tannin. The tannin produced 
 in the leaves passes into the branches and roots, and 
 there is no experimental evidence that the tannin which 
 has once passed into the rhizome undergoes further 
 
20 
 
 THE TANNINS. 
 
 change; there is rather an increase in the amount of 
 tannin in the rhizome through a production in the dark. 
 Kraus inclined to the belief that the use of tannin in 
 leaves is either to protect them from being eaten or to 
 prevent rotting, etc. Fallen leaves contain as much 
 tannin as they did during their best time of growth, 
 indicating that the leaf tannin is of no value to the 
 plant. During the germination in the dark of seeds 
 containing tannin, as oak and horse-chestnut, there is 
 no diminution, but an increase, in the amount of tannin. 
 There is not yet sufficient evidence to show whether 
 tannin is produced from non-nitrogenous substances, or 
 whether it is formed in the conversion of nitrogenous 
 compounds into albuminoids. Finally, Kraus con¬ 
 sidered it probable that aromatic compounds may be 
 formed in the production of albumen, some of which 
 are used in the building up of albumen while others 
 yield tannin. His investigations and conclusions rested 
 on slight differences in the estimation of tannin, and 
 Reinitzer claimed that the methods employed for the 
 estimation of tannin are not sufficiently exact for phys¬ 
 iological investigation. This is no doubt true of esti¬ 
 mations made by different chemists, but one person 
 should be able with the present methods to get results 
 which are relatively accurate. 
 
 It was early suggested to divide the tannins into two 
 classes,—the iron-bluing tannins, or those which give 
 blue precipitates, and the iron-greening tannins, or those 
 which give green precipitates with salts of iron. It 
 lias been found, however, that the same tannin may 
 produce both blue and green precipitates with iron salts. 
 Free acid, especially tartaric, causes the green color, 
 
GENERAL CHARACTERS. 
 
 21 
 
 and, on the other hand, an iron-greening tannin may 
 be changed to an iron-bluing one by the cautious addi¬ 
 tion of alkali. 
 
 A more recent and much more ex act classification is 
 that of Wagner into 'pathological tannins, those formed 
 on vegetable tissue by the sting of an insect, and 'phys¬ 
 iological tannins, those occurring in vegetable tissue. 
 To the former class belongs gallotannic acid, and to the 
 latter the great number of tannins found throughout 
 the vegetable kingdom. The former give blue and the 
 latter give both blue and green precipitates with salts of 
 iron. It has been found that some of the latter class 
 are identical with gallotannic acid ; this was first pointed . 
 out to be true of sumactannic acid by Stenhouse, and 
 was later confirmed by Lowe. 
 
 The method of preparing a tannin depends very 
 much on the character of the material in which it 
 occurs. Most of the published processes are based on 
 the use of galls as the source, and a process available 
 for exhausting them is not adapted to extracting a hard 
 woody substance containing only five or ten per cent, 
 of tannin. A process will, therefore, be given for each 
 tannin, unless it can be referred to the following gen¬ 
 eral method, which will be found available in many 
 cases. 
 
 The finely-powdered material is packed in a perco¬ 
 lator and extracted with commercial ether. The offi¬ 
 cial ether of the United States Pharmacopoeia, contain¬ 
 ing seventy-four parts ether, twenty-six parts alcohol, 
 and a small quantity of water, gives satisfactory results; 
 its specific gravity is very close to 0.750. The ether is 
 recovered by distillation, the last portions being removed 
 
 A 
 
 
 iw 
 
22 
 
 THE TANNINS. 
 
 under reduced pressure, and the residue is dissolved in 
 such a quantity of water as will allow the solution to 
 filter readily. This aqueous solution is distilled to dry¬ 
 ness under reduced pressure, and the residue dissolved in 
 a small quantity of water and rapidly distilled to dry¬ 
 ness in as near a vacuum as possible, using in this, as in 
 the preceding cases, a water-bath as the source of heat, 
 when the tannin will “ puff up” and remain as a light- 
 or dark-brown residue, according to the character of the 
 original material. It may then be purified according to 
 the method given later for the purification of gallotan- 
 nic acid. This process may be used for most substances 
 which contain five per cent, of tannin or over; but it is 
 well to bear in mind that there is no separation of the 
 percolate into layers, as in the case of that from galls. 
 
 If less than five per cent, of tannin be present, it is 
 more economical to extract with water and precipitate 
 the tannin with lead acetate. The resulting lead tan- 
 nate is then suspended in water, decomposed by hydro¬ 
 gen sulphide, and the filtrate from lead sulphide dis¬ 
 tilled to dryness under reduced pressure. Alcohol is 
 sometimes used, but where the solvent can be recovered 
 it has few if any advantages over ether. When econ¬ 
 omy is the first consideration hot water is used, and this 
 will later claim especial attention under tannin extracts. 
 In a few cases cold instead of hot water must be used 
 or the impurities will predominate, as in the case of 
 canaigre, which contains a large quantity of starch that 
 is dissolved with the tannin by hot water and interferes 
 with the use of the extract for many purposes. 
 
 Always when a pure tannin is desired heat and ex¬ 
 posure to air must be avoided. Many plants appear 
 
GENERAL CHARACTERS. 
 
 23 
 
 to contain two tannins; when such is the case it will 
 sometimes be found that ether extracts one, and the 
 other may then be removed by water, or occasionally 
 cold water will extract but one and the other may then 
 be removed by the use of hot water. 
 
 The tannins as a class are amorphous, odorless, 
 slightly acid, and strongly astringent compounds, of a 
 color varying from dark brown to pure white. They 
 are, with few exceptions, soluble in water, alcohol, ether, 
 and glycerin, and insoluble in chloroform, benzol, pe¬ 
 troleum ether, carbon disulphide, fixed and volatile 
 oils. 
 
 In addition to the above reactions given with iron 
 salts, most if not all the tannins give brown precipitates 
 with potassium bichromate. Lime-water gives precip¬ 
 itates, which, however, vary in color; at first they are 
 white, but become rapidly darker, some red and others 
 blue. Strong solutions of the alkaline carbonates also 
 precipitate them. All the tannins are precipitated by 
 gelatin or albumen; solutions of alum and ammonium 
 chloride render the precipitation more complete. Sat¬ 
 urated solutions of sodium chloride, calcium chloride, 
 potassium acetate, and a number of other salts precipi¬ 
 tate the tannins from solution ; the same is true of 
 moderately concentrated sulphuric and hydrochloric 
 acids. Concentrated sulphuric acid dissolves the dry 
 tannins with a yellow color, which on heating become 
 dark-red rufigallic acid and then black metagallic acid. 
 Nitric acid does not precipitate the tannins from solu¬ 
 tion, but it dissolves the dry compounds with a yellow 
 color, and decomposes them with the formation of 
 oxalic acid. Other oxidizing reagents, as potassium 
 
24 
 
 THE TANNINS. 
 
 bichromate and permanganate, decompose them very 
 easily into carbon dioxide and some other unknown 
 compound. When heated dry with arsenic acid, some 
 of them are converted into ellagic acid. Most tannins 
 are precipitated by alkaloids, notwithstanding the fact 
 that both frequently exist in the same plant without 
 forming an insoluble compound. The action of dilute 
 acids and alkalies is one of considerable importance in 
 determining their character; some, for instance, when 
 heated to 100° with a one or two per cent, hydro¬ 
 chloric acid solution, yield crystalline compounds as 
 gallic and ellagic acid, while others yield dark-colored 
 amorphous compounds allied to the phlobaphenes; 
 glucose is formed at the same time in nearly all the 
 decompositions, thus showing their glucosidal nature. 
 
 Another method of determining the character of 
 tannins is by the application of heat. When a tan¬ 
 nin is heated to 120° no decided change takes place 
 except a slight darkening in color; on continuing the 
 heat the color gradually becomes darker, until at 160° 
 decomposition takes place. With some tannins the 
 products are metagallic acid and pyrogallol, and with 
 others metagallic acid and catechol. It has been sug¬ 
 gested to divide the tannins into two classes according 
 as they yield, when heated, pyrogallol or catechol. 
 Those which produce a brownish-colored deposit on 
 leather, called “bloom,” and form blue compounds with 
 ferric salts yield, when heated, a sublimate of pyro¬ 
 gallol, while those which do not form a “ bloom” on 
 leather and give green compounds with ferric salts 
 yield, when heated, a sublimate of catechol. To the 
 former class belong the tannins from galls, sumac, 
 
GENERAL CHARACTERS. 
 
 25 
 
 chestnut,, and oak, and to the latter those from hem¬ 
 lock, catechu, rhatany, and mangrove. It is known 
 not only that the tannins in the two classes have a dif¬ 
 ferent composition, but that most of those in the same 
 class differ from one another in many particulars. In 
 order to assist one in determining the character of a 
 tannin it is necessary to study its decompositions by 
 heat alone, by acids, and by alkalies. 
 
 Procter, in his “ Text-Book of Tanning,” and Allen, 
 in his “ Commercial Organic Analysis,” have given 
 similar schemes for carrying out these three processes. 
 
 The decomposition by heat may be effected by heat¬ 
 ing the sample in a small glass retort, but this is at¬ 
 tended with considerable loss from a portion becoming 
 overheated. The decomposition should take place by 
 slowly raising the temperature from 160° to 215°, 
 keeping it between 200° and 210° for twenty minutes. 
 It has been suggested to assist the sublimation of the 
 volatile products by leading a stream of carbon dioxide 
 into the retort to carry them off as rapidly as formed. 
 
 Thorpe suggested a method of preparing pyrogallol 
 for photographic purposes by heating gallic acid in 
 glycerin as above directed, and this has since been 
 applied to decomposing the tannins. 
 
 The details of the method are to heat one gramme 
 of the tannin in 5 cc. of glycerin, slowly raising the 
 temperature from 160°, and keeping it for from twenty 
 to thirty minutes between 200° and 210°. It is then 
 allowed to cool, 20 cc. of water are added, and the 
 liquid is shaken with an equal volume of ether with¬ 
 out previous filtration. The separated ethereal layer 
 is evaporated to dryness and dissolved in 50 cc. of 
 
 3 
 
26 
 
 THE TANNINS. 
 
 water and tested for pyrogallol and catechol, according 
 to the following: 
 
 
 One pee cent. Solutions op 
 
 
 Pyrogallol. 
 
 Catechol. 
 
 Ferric chloride . . . 
 
 Red color, turning 
 brown. 
 
 Green color. 
 
 Ferric acetate . . . 
 
 Dark-purple color. 
 
 Green color. 
 
 Lime-water .... 
 
 Purple color, turn¬ 
 ing brown. 
 
 Clear red color. 
 
 Melting-point . . . 
 Pine wood moistened 
 
 131°. 
 
 111°. 
 
 with HC1. 
 
 No change. 
 
 Violet color. 
 
 The above tests will readily distinguish between 
 pyrogallol and catechol when either occurs singly or 
 mixed with only a small proportion of the other, but 
 when they occur in a solution in nearly equal propor¬ 
 tions it becomes a matter of much more difficulty. 
 The tannin should be free from gallic acid and catechin 
 before submitting it to the above operation, or else 
 pyrogallol will be obtained from the former and cat¬ 
 echol from the latter; this may be Accomplished by 
 thorough agitation of an aqueous solution of the tannin 
 with ether and separation of the latter, the water is 
 then rapidly distilled from the tannin under reduced 
 pressure. 
 
 It has been found by the author, in carrying out the 
 application of heat to tannins, that there is a practical 
 difficulty iu separating the ethereal layer containing 
 pyrogallol and catechol when the 5 cc. of glycerin, 
 after the application of heat, are dissolved in 20 cc. 
 of water and agitated with ether. The emulsion formed 
 
GENERAL CHARACTERS. 
 
 27 
 
 is difficult to get rid of. This may be overcome by 
 agitating the 5 cc. of glycerin directly with 20 cc. of 
 ether without first dissolving in water, or the sample of 
 tannin may be heated with 5 grammes of paraffin, in¬ 
 stead of 5 cc. of glycerin, and the paraffin dissolved in 
 petroleum ether; the residue is then treated with water 
 and agitated with ether, the ethereal solution separated 
 as before, evaporated, and the residue dissolved in 
 50 cc. of water, when it is ready for testing. 
 
 In order to determine the effect of dilute acids on a 
 sample, a convenient quantity of the latter is heated for 
 an hour or more to 100° with a two-per-cent, solution 
 of absolute hydrochloric acid. This may be accom¬ 
 plished by heating in a sealed tube or strong flask 
 tightly stopped, or by attaching the open flask to an up¬ 
 right condenser and heating with a vigorously boiling 
 water-bath. The solution, after sufficient heating, is 
 allowed to cool, when a separation of insoluble matter 
 indicates ellagic acid, anhydrides, or phlobaphenes. 
 The mixture is filtered, if a separation has taken place, 
 and the precipitate tested for ellagic acid by nitric acid, 
 with which it forms an intense crimson color. The 
 filtrate containing hydrochloric acid, undecomposed 
 tannin, gallic acid, and glucose is agitated with ether 
 to remove gallic acid, neutralized with sodium hydrate, 
 and precipitated with basic lead acetate to remove 
 coloring-matter and tannin. The excess of lead is 
 removed with sulphuric acid, again neutralized with 
 sodium hydrate, and the clear filtrate heated with an 
 excess of Feh ling’s solution. The formation of a red 
 precipitate of cuprous oxide indicates the presence of 
 glucose. 
 
28 
 
 THE TANNINS. 
 
 The ethereal solution which removed gallic acid is 
 evaporated, the residue, dissolved in warm water, al¬ 
 lowed to cool, and filtered, when gallic acid, if present 
 in the filtrate, may be detected by the red coloration 
 produced by the addition of a few drops of potassium 
 cyanide solution. 
 
 Since glucose occurs as a mixture in most tannins, it 
 is necessary first to get rid of it before applying the 
 above process. This may be accomplished by repeated 
 purification of the tannin by precipitation with lead 
 acetate; but such a process is very slow and tedious: 
 so it has been suggested to use the lead salt for heating 
 with the acid, in which case the sediment which sepa¬ 
 rates when the liquid cools will consist in part or all of 
 lead chloride, which may be collected on a filter with 
 the ellagic acid and treated with boiling water, in which 
 the lead chloride will dissolve. 
 
 It has been found by the author that the shortest 
 method is to determine the amount of glucose in a 
 tannin by removing the latter with lead acetate, and 
 the excess of lead with hydrogen sulphide. The fil¬ 
 trate is then heated on a water-bath until every trace 
 of hydrogen sulphide is driven off, neutralized with 
 sodium hydrate, filtered, and the glucose estimated in 
 the filtrate gravimetrically with Fehling’s solution. 
 Another portion of the sample is then heated with 
 hydrochloric acid, and, after carrying out the process 
 of hydrolysis, the glucose is estimated. Any excess of 
 glucose in the second estimation over that in the first 
 indicates that much glucose existed in the tannin as 
 glucoside. 
 
 The action of alkalies is determined either on a sample 
 
GENERAL CHARACTERS. 
 
 29 
 
 of the tannin or on the anhydrides and phlobapheues 
 resulting from the action of hydrochloric acid. This 
 process of heating the tannins with alkali converts some 
 of them into protocatechuic acid and either phloroglucol 
 or acetic acid,—to this class belong the catechol tannins. 
 Another class are converted into gallic and ellagic acids 
 by the alkali, and they are found to be the pyrogallol 
 tannins. The operation is carried out by taking 20 
 grammes of the sample and boiling for three hours with 
 150 cc. of potassium hydrate solution, specific gravity 
 1.20 ; the liquid is then concentrated with constant 
 stirring until it becomes pasty. It is then cooled and 
 neutralized with dilute sulphuric acid, filtered from the 
 potassium sulphate, and the filtrate treated with sodium 
 bicarbonate until the acid is neutralized. The liquid 
 is agitated successively with several portions of ether; 
 the latter, after separation, is recovered by distillation, 
 and its residue dissolved in water; from this solution 
 protocatechuic acid is removed by lead acetate, filtered, 
 and the phloroglucol, when present, removed from the 
 filtrate by ether; the latter is evaporated, and the 
 phloroglucol is recognized by its sweet taste, by ferric 
 chloride, which imparts to its aqueous solution a deep 
 violet-red color, and by bromine-water, which causes 
 a separation of crystalline needles, with evolution of 
 heat and a very irritating odor. 
 
 With these various characters of the tannins our 
 knowledge of them almost ceases. Except gallotannic 
 and quercitannic acids the individuals have not been 
 much studied, and the latter are only now in course of 
 investigation by Bottinger. As recently as 1881, Dar- 
 ton, who has had considerable experience in the assay of 
 
 3* 
 
30 
 
 THE TANNINS. 
 
 various tannin materials, ventured to repeat the conclu¬ 
 sion of the older chemists that we have but one tannin, 
 and that the differences are due to the other materials 
 with which they are associated in the plant. It is true 
 that one is often led, during the practical study of the 
 subject, to ask whether we have more than one tannin 
 or not, but this question is being answered as the study 
 into the constitution of the various members is prose¬ 
 cuted. No doubt some relationship governing them 
 exists, just as there is among the sugars, but as yet it 
 has not been made out, and the study will necessarily 
 be a long one, since there are so many individual tan¬ 
 nins to be investigated. The problem will undoubtedly 
 be worked out by a study of the derivatives, and this 
 by means of bromine and acetyl has been well com¬ 
 menced on the gallotannic and quercitannic acids. We 
 must keep in mind that a number of the individual 
 tannins will be proved to be identical, as has been 
 shown to be the case with sumac and a few others in 
 regard to gallotannic acid, but with the great majority 
 our present knowledge leads to the belief that a rela¬ 
 tionship only is to be worked out. 
 
 In general it may be said that the tannins are used 
 in medicine, in the manufacture of leather and ink, and 
 as a mordant in dyeing, but the special properties of 
 the different members adapt them to a great number of 
 minor uses. By far the largest amount of tannin is 
 used in an impure state,—that is, in the form of an in¬ 
 fusion or decoction, or as an extract, made by concen¬ 
 trating these solutions. 
 
SECTION III. 
 
 THE DETECTION AND ESTIMATION OF THE TANNINS. 
 
 The simple detection of the tannins is comparatively 
 easy. A few tests applied to an infusion of the plant 
 or substance serve to decide their presence or absence. 
 
 Ferric acetate or chloride is usually first employed, 
 when a green or blue color and precipitate indicate 
 tannin. Ferrous salts, when free from ferric, cause 
 no change with tannin solutions unless the latter be 
 concentrated, when a white gelatinous precipitate is 
 formed, rapidly becoming dark on exposure to air. 
 Potassium dichromate forms brown precipitates with 
 nearly all tannins. Ammoniacal copper sulphate forms 
 precipitates of different shades of color; but, according 
 to Procter, the tannin of Hungarian larch is not pre¬ 
 cipitated by this reagent, and it does form insoluble 
 compounds with some substances other than the tan¬ 
 nins. Allen recommends an ammoniacal solution of 
 potassium ferricyanide, which produces with the tan¬ 
 nins a deep-red color changing to brown, even in very 
 dilute solutions. Most of the alkaloids, when not in 
 too dilute solution, produce whitish precipitates with 
 the tannins. Calcium hydrate produces a whitish pre¬ 
 cipitate rapidly turning blue with gallotannic, but red 
 with some other varieties, notably that from mangrove. 
 An aqueous solution of iodine in potassium iodide, 
 mixed with a small quantity of ammonia previously 
 
 31 
 
32 
 
 THE TANNINS. 
 
 diluted with ten times its volume of water, will pro¬ 
 duce a brilliant red color with solutions of the tannins, 
 even when highly diluted. 
 
 Other characteristic tests for the tannins will be found 
 under the chemical properties of the different varieties. 
 
 The methods for the quantitative determination of 
 the tannins may conveniently be considered in four 
 groups: 
 
 1. Miscellaneous methods, not belonging to any of 
 the following. 
 
 2. Precipitation by metallic salts. 
 
 3. The gelatin or hide methods. 
 
 4. The permanganate methods. 
 
 1. Under the first class is the process of Commaile, 
 which was based on the reduction of iodic acid by 
 tannin in the presence of hydrocyanic acid. The iodic 
 acid not consumed was estimated by reduction with 
 sulphurous acid and precipitation by silver nitrate. 
 This method has been unfavorably criticised by Cecil 
 and by Watts. 
 
 P. Becker suggested the use of methyl violet, 0.250 
 gramme in one litre. This was standardized by a one- 
 per-cent. tannin solution, and it could then be used on 
 tannin solutions of unknown strength. 
 
 Mittenzwey recommended a process in which the 
 volume of oxygen absorbed by an alkaline solution of 
 tannin was measured. Cecil found this to give unsat¬ 
 isfactory results, but Watts, after improving some 
 details in the apparatus, considered it a fairly accurate 
 method. 
 
 Wagner proposed titrating the tannin solution with 
 cinchonine sulphate, using rosaniline acetate as an indi- 
 
DETECTION AND ESTIMATION OF TANNINS. 33 
 
 cator. This method failed to give satisfaction, on ac¬ 
 count of the difficulty in determining the end of the 
 reaction. Clark used a modification of this for the 
 estimation of tannin in tea. His improvement con¬ 
 sisted in adding an excess of the cinchonine sulphate, 
 filtering, and estimating the excess of the alkaloid by 
 titrating with potassio-mercuric iodide. A series of 
 trials, by the author of this volume, in which the 
 method was tried on gallotannic acid, failed to give 
 concordant results. 
 
 F. Musset suggested using an excess of standard so¬ 
 lution of iodine, and, after twelve hours’ standing, 
 titrating the free iodine with standard sodium thiosul¬ 
 phate, which was added in excess and titrated with 
 decinormal iodine solution and starch. 
 
 2. The methods of precipitation with metallic salts 
 are very numerous and comprise many modifications. 
 It is desirable sometimes to obtain the value of a tan¬ 
 nin by this means, therefore the following more impor¬ 
 tant processes will be given. 
 
 Pribram in 1866 detailed a method involving pre¬ 
 cipitation by lead acetate, washing, drying, and weigh¬ 
 ing the precipitate; but, as there are at least three 
 salts of lead tannate, according as the lead acetate or 
 tannin is in excess, and these salts are readily decom¬ 
 posed by washing, it is evident that such a method can 
 only give approximations. 
 
 Allen originated a modification of this for assaying 
 the tannin in tea, in which the latter in hot concen¬ 
 trated solution was titrated by a volumetric solution of 
 the lead acetate; the end of the reaction was ascertained 
 by filtering a small portion of the liquid and testing with 
 
34 
 
 THE TANNINS. 
 
 ammoniacal potassium ferricyanide, which gave a red 
 color turning brown as long as any uncombined tannin 
 was present. As stated by its author this estimation in¬ 
 cluded gallic acid, so would not be available for all cases. 
 
 Dragendorff 1 recommended that precipitations with 
 lead acetate should be carried out in moderately con¬ 
 centrated solutions, avoiding an excess of the lead salt 
 and not continuing the washing too long. 
 
 R. Jackson suggested the use of lead carbonate with 
 which to agitate the tannin solution. The specific 
 gravity before and after the treatment giving the loss 
 of tannin, a difference of .0038 indicated one per cent, 
 of tannin. 
 
 For the estimation of tannin in plant analysis Drag¬ 
 endorff recommended estimating the tannin soluble in 
 absolute alcohol, after replacing the solvent by water, 
 by precipitating with lead acetate, rapidly washing, 
 drying, and weighing the precipitate, which was then 
 burned and the residue of lead oxide subtracted from 
 the original weight. This operation was then repeated 
 with copper acetate. When the amount of organic 
 matter precipitated by each was equal, the substance 
 was assumed to be tannin; but, in case the lead salt 
 precipitated more than the copper salt, the organic 
 matter obtained by the latter was taken as representing 
 the amount of tannin, while the excess obtained by lead 
 acetate over that by copper acetate was reckoned as 
 other organic acids and coloring-matter. 
 
 Copper acetate appears to have been first suggested 
 for the quantitative determination of tannin by Sakur. 
 
 1 Plant Analysis, English edition, p. 41. 
 
DETECTION AND ESTIMATION OF TANNINS. 35 
 
 The precipitate with it, like that of the corresponding 
 lead salt, is not of constant composition; therefore the 
 precipitation must be made with moderately concen¬ 
 trated solutions, and the resulting precipitate rapidly 
 washed, dried, and weighed. Fleck precipitated the 
 tannin by copper acetate, and washed the precipitate 
 with ammonium carbonate to remove gallic acid. The 
 precipitate was then washed, dried at 100°, weighed, 
 and ignited. Wolff found 100 parts of cupric oxide 
 represented 130.4 parts of tannin. 
 
 Pavesi and Rotondi found 100 parts represented 145 
 parts tannin. This difference among different investi¬ 
 gators Schiff explained by supposing they used tannins 
 of variable degrees of purity, and he found 136 parts 
 of pure digallic acid to be represented by 100 parts of 
 cupric oxide. 
 
 J. Persoz recommended dissolving eight grammes of 
 ammonium chloride in one litre of water, and in this 
 dissolving some stannous chloride. Ten grammes of 
 pure dry tannin were then dissolved in one litre of 
 water, and 100 cc. of this solution precipitated with 
 100 cc. of this stannous chloride solution, the mixture 
 allowed to stand ten or twelve hours in a graduated 
 cylinder, and the volume of the precipitate read. Then 
 ten grammes of the tannin material were boiled for 
 one-half hour with a half-litre of water, filtered, and 
 the residue washed with sufficient water to make one 
 litre; 100 cc. of this solution in a similarly graduated 
 cylinder were then precipitated with 100 cc. of the stan¬ 
 nous chloride solution, and after standing ten or twelve 
 hours the volume of the precipitate was compared with 
 that from the pure tannin. 
 
36 
 
 THE TANNINS. 
 
 Risler-Beunat proposed to modify the method by col¬ 
 lecting the precipitate of tin tannate, washing, drying, 
 and igniting, with the addition of a little ammonium 
 nitrate in order to completely convert the residue into 
 stannic oxide. The weight of this residue was con¬ 
 verted into tannin by a calculation based on the amount 
 of residue obtained from a pure dry tannin. Dragen- 
 dorff found that the precipitation was incomplete, that, 
 it took place slowly, and that the precipitate was partly 
 decomposed by washing. 
 
 Gerland suggested the use of tartar emetic in the 
 presence of ammonium chloride for the volumetric es¬ 
 timation of tannin; the method, however, met with 
 little favor until improved by Richards and Palmer, 
 who used ammonium acetate instead of the chloride, 
 both of which prevent the precipitation of gallic acid 
 and assist the precipitation of the tannin. The tartar 
 emetic was dried at 100°, and then used in the propor¬ 
 tion of 6.730 grammes in one litre; in such a solution 
 1 cc. corresponded to 0.010 gramme of digallic acid. 
 The ammonium acetate was made by saturating glacial 
 acetic acid with strong solution of ammonia, and 1 cc. 
 of this solution added to every 25 cc. of the tannin 
 solution, which latter should contain from 0.1 to 0.3 
 gramme of tannin in every 100 cc. Three or four tests 
 should be made in as many beakers placed side by side, 
 and the end of the reaction determined by placing a 
 drop of the clear supernatant liquid on a white porce¬ 
 lain surface, adding a drop of sodium thiosulphate, and 
 warming; a red color of antimony sulphide will form 
 when the least excess of the reagent has been added. 
 
 Ammoniacal zinc acetate was recommended by 
 
DETECTION AND ESTIMATION OF TANNINS. 37 
 
 Terreil in 1874, by Carpene in 1876, and by Barbieri in 
 1877: While the details of the different authors varied 
 somewhat, the following covers most of the methods. 
 The reagent was added to a boiling solution of the tan¬ 
 nin, and the mixture concentrated to one-half, when it 
 was cooled and filtered. The precipitate was dissolved 
 in dilute sulphuric acid, and the tannin estimated by 
 titration with potassium permanganate, This process 
 was especially recommended for determining the tannin 
 in wine, but Dragendorff found it of little value. 
 
 Handtke used ferric acetate in the presence of sodium 
 acetate, and found it available for the estimation of the* 
 tannins of oak-bark, valonia, dividivi, sumac, and cate¬ 
 chu, when the concentration was such that the precipi¬ 
 tate yielded 45.8 per cent, of ferric oxide by ignition; 
 but with a number of tannins it did not yield satisfactory 
 results, and the process is apparently not used. 
 
 3. Methods of estimating tannins by means of gela¬ 
 tin, isinglass, and hide or hide powder have been sug¬ 
 gested in great number, with as many or more modi¬ 
 fications by others until the list is a formidable one. 
 Apparently the first paper on the quantitative determi¬ 
 nation of tannin was by George Biggin in 1799, who 
 collected, washed, dried, and weighed the precipitate 
 produced by gelatin on tannin. He did not attempt to 
 arrive at the exact amount of tannin present, as he 
 made no estimation of the value of the precipitate in 
 tannin. It could, therefore, be used only to compare 
 one material with another, and was available only to 
 the tanner who wished to compare the value of a new 
 substance with that of a Avell-known one he was using. 
 
 Davy in 1803 extracted six parts of bark with 
 4 
 
38 
 
 THE TANNINS. 
 
 water and precipitated it with one part of isinglass, 
 washed, dried, weighed the precipitate, and calculated 
 40 per cent, of it as tannin. 
 
 Muller suggested the addition of alum to the isin¬ 
 glass or gelatin solution, and a solution of three 
 grammes gelatin and one gramme alum in one litre of 
 water is largely used at the present time in two modi¬ 
 fications,—one to collect, wash, dry, weigh the precipi¬ 
 tate, and reckon 54 per cent, of it as tannin ; the other 
 to use the solution, volumetrically and determine the 
 end of the reaction by filtering off a small portion of 
 the solution and testing until no further precipitate is 
 caused by the reagent. The solution of gelatin and 
 alum must first be standardized by a solution of pure 
 tannin. Notwithstauding the objection to this method, 
 and the fact that we have many others for which 
 greater accuracy is claimed, it continues to be used, and, 
 no doubt, in careful and experienced hands will yield 
 uniform results. 
 
 The following details of this process have been em¬ 
 ployed by the author for several years with consider¬ 
 able success. The results have in most cases agreed 
 closely with those obtained by the permanganate 
 method. The solution is made of 2.5 grammes gelatin 
 and 10 grammes alum in one litre. This solution, as 
 well as that of the tannin, is warmed to 70°. The re¬ 
 agent is then dropped in with constant stirring until 
 the precipitate coagulates and leaves a clear superna¬ 
 tant licpiid which gives no further precipitate on the 
 addition of a few drops of the reagent. In case the 
 coagulation does not take place so as to furnish a clear 
 liquid and one that filters easily, the whole should be 
 
DETECTION AND ESTIMATION OF TANNINS. 39 
 
 thrown out and a more dilute solution of the tannin 
 material taken. When precipitation has taken place 
 satisfactorily, the mixture should be rapidly poured on 
 two counterpoised filters placed one iuside the other, the 
 precipitate washed with just sufficient warm water to re¬ 
 move alum, dried at 110°, and weighed. For gallotannic 
 acid 54 per cent, of the precipitate should be considered 
 tannin. With the amount of alum above mentioned it 
 is possible to add the gelatin solution in slight excess 
 without dissolving any of the precipitate. 
 
 According to Jolmnson 100 parts of gelatin precipi¬ 
 tate 120 parts of dry tannin. 
 
 Schulze recommended the use of ammonium chloride 
 to cause coagulation of the precipitate; his solution 
 contained ten grammes of gelatin in one litre saturated 
 with ammonium chloride, and Lowenthal used a satu¬ 
 rated solution of common salt with one-tenth its volume 
 of hydrochloric acid (specific gravity 1.120) for the same 
 purpose, but, if the proportion of alum (10 grammes 
 to 1 litre) recommended above be used and the details 
 carefully carried out, it will be found preferable. 
 
 Powdered or rasped raw-hide was originally sug¬ 
 gested by Davy and more recently used in the process 
 of Hammer. This method consisted in preparing a 
 solution of the tannin material, taking its specific 
 gravity, then digesting it for a few hours with hide to 
 four times the supposed amount of tannin present, 
 which latter should be present to the extent of from 3 
 to 5 per cent., filtering, and again taking the specific 
 gravity. The loss in specific gravity on account of di¬ 
 gesting with hide represented the tannin, a loss of .0040 
 indicating one per cent. 
 
40 
 
 THE TANNINS. 
 
 There are many sources of error in this process, as 
 has been pointed out by Ran, who says, “A 5-per-cent, 
 solution of gallotannic acid had a specific gravity of 
 1.01841. The density of distilled water being 1.0000, 
 the 5 per cent, gallotannic acid was represented by the 
 increase in specific gravity 0.01841. A solution of cane- 
 sugar was prepared having specific gravity 1.01646, 
 and 5 per cent, of the same gallotannic acid dissolved 
 therein. The specific gravity of the latter solution was 
 then found to be 1.03398; consequently the same per¬ 
 centage of tannin was in this case represented by a 
 somewhat smaller increase in specific gravity, 0.01752.” 
 The same author by experiments showed that the col¬ 
 oring-matters of logwood and Persian berries were 
 largely absorbed by the hide powder along with the 
 tannin. 
 
 Simand recommended the use of bone tissue instead 
 of hide powder. This bone tissue he prepared by 
 taking tubular bones free from joints, macerating them 
 for two days with a five-per-cent, solution of soda, 
 thoroughly washing with water, reducing to smaller 
 pieces, and treating with dilute hydrochloric acid until 
 softened, then washing and passing through a grind¬ 
 ing machine while still wet. This comminuted mass 
 was treated with dilute hydrochloric acid, thoroughly 
 washed, pressed, and dried. 
 
 Simand and Weiss estimated the tannin in extracts 
 by hide powder, which they prepared from fresh skin 
 by washing, unhairing, treating with dilute hydro¬ 
 chloric acid, stretching, and drying. The skin was then 
 planed fine, dried, and worked through a fine sieve. 
 The watery residue from 5 grammes of this powder 
 
DETECTION AND ESTIMATION OF TANNINS. 41 
 
 gave only 0.036 gramme dry residue, containing 0.008 
 gramme ash. 
 
 In order to estimate a sample of tannin extract, from 
 12 to 16 grammes of a solid or 22 to 28 grammes of a 
 liquid sample were taken, dissolved in distilled water, 
 made up to one litre, and filtered ; 100 cc. were evap¬ 
 orated to dryness, dried, and weighed, thus giving the 
 total amount of soluble matter; 250 cc. of the solution 
 were placed in a dry flask with one gramme of hide 
 powder and shaken for two hours, then filtered into 
 another flask and this treatment with one gramme of 
 hide powder twice more repeated, and then a fourth 
 time with 2 grammes of hide powder. This quan¬ 
 tity (5 grammes) was considered quite sufficient to ex¬ 
 tract all tanning material. The solution was then fil¬ 
 tered for the fourth time and 100 cc. evaporated and 
 dried. The difference between this weight and that 
 obtained by the first evaporation indicated the amount 
 of tannin. 
 
 Bone tissue as well as hide powder is available for 
 this process, which has many points of value, and, if 
 the correction for the solubility of the hide powder or 
 bone tissue could be accurately made, it would be the 
 most satisfactory and exact of the numerous methods 
 that have been proposed. In actual practice, however, 
 it has been found almost impossible to get a gelatinous 
 tissue that is not somewhat soluble in water, which 
 solubility should be added to the amount of tannin 
 found, but, as most of the soluble portion is capable of 
 being precipitated by tannin, it is not proper to add 
 the whole amount of tissue which is dissolved by water, 
 therefore the correction is an unknown quantity, and, 
 
 4* 
 
42 
 
 THE TANNINS. 
 
 unless a gelatinous tissue can be made that is com¬ 
 pletely insoluble in water, the process is not available. 
 
 Muntz and Ramspacher contrived an apparatus for 
 use in Hammer’s method, which consisted of a press so 
 constructed that the tannin solution could be forced 
 through hide, the specific gravity taken before and 
 after, or a portion of the liquid evaporated in each 
 case. It, however, had no advantages over the original 
 method, and has been used but little. 
 
 4. Under the fourth class of methods we have prac¬ 
 tically one in which the use of potassium permanganate 
 is combined with the gelatin or hide method. The use 
 of calcium hypochlorite has been suggested to replace 
 the permanganate, but with no apparent advantage. 
 
 Monier in 1858 first proposed the use of potas¬ 
 sium permanganate for volumetrically determining the 
 amount of tannin by adding the reagent until the 
 solution assumed a pinkish color. It was soon found, 
 however, that tannin was not the only substance oxi¬ 
 dized by permanganate, and in infusions the color 
 interfered with the determination of the end reaction. 
 
 In 1860, Lowenthal rendered the process more avail¬ 
 able by suggesting the use of indigo as an indicator, 
 which at the same time controlled the oxidation, and 
 this he further greatly improved in 1877 by combining 
 the gelatin process with it, making a permanganate 
 valuation, before and after treatment with gelatin. 
 Neubauer in 1871 suggested a similar improvement, 
 using animal charcoal instead of gelatin. 
 
 The permanganate method, with further improve¬ 
 ments by Procter, Hunt, Yon Schroder, Councler, and 
 others, has come to be regarded as the standard process 
 
DETECTION AND ESTIMATION OF TANNINS. 43 
 
 of the present time, although it is not without its faults, 
 and is especially difficult for one who only occasionally 
 desires to make a tannin assay. 
 
 In 1883 a Commission of German technical chemists 
 was appointed to meet in Berlin and report on a 
 method of tannin assay. This Commission consisted 
 of Dr. C. Councler, Dr. J. v. Schroder, and Messrs. 
 A. Eberz, Franz Kathreiner, Schaun, and F. Simand. 
 W. Eitner, of Vienna, was prevented from taking part 
 in the proceedings. In two years they presented a 
 report, under the title of “Bericht liber die Verhand- 
 lungeu der Commission zur Feststellung einer einheit- 
 lichen Methodeder Gerbstoffbestimmung, Cassel, 1885. 
 Verlag von Theodor Fischer.” In addition to the 
 recommendations, this report contains a critical investi¬ 
 gation of the Lowenthal method by Dr. von Schroder. 
 
 The following process will give that recommended 
 by the Commission, together with some improvements 
 that have been suggested by various investigators since. 
 Although far from perfect, it may be said to represent 
 fairly the method of to-day, and is capable of giving 
 satisfactory results in competent hands. 
 
 Briefly outlined, the process, which is still known as 
 Lowenthal’s, consists in taking a dilute solution of po¬ 
 tassium permanganate, determining the amount of it 
 necessary to decolorize or change to yellow a given 
 amount of indigo solution, and then the amount re¬ 
 quired to change the same volume of indigo solution 
 and pure tannin solution. Another portion of the tan¬ 
 nin solution is then treated with gelatin or hide pow¬ 
 der, filtered, and portions of the filtrate and indigo 
 which represent the same amounts as were previously 
 
44 
 
 THE TANNINS. 
 
 treated with permanganate are again decolorized by 
 that reagent. The difference in volume of perman¬ 
 ganate solution used before and after treatment with 
 gelatin gives the amount of permanganate required to 
 oxidize this known amount of tannin. 
 
 This tannin solution can then be replaced by an in¬ 
 fusion which represents a known quantity of tannin 
 material, and the percentage readily calculated. The 
 indigo serves as an indicator and at the same time con¬ 
 trols the oxidation ; since it is decolorized with some 
 difficulty, it indicates that the other substances have all 
 been oxidized when the blue color disappears. 
 
 SAMPLING AND PREPARATION OF THE TANNIN 
 INFUSION. 
 
 From 500 to 1000 grammes are so taken as to rep¬ 
 resent the whole cargo. This sample is then ground in 
 a drug-mill or powdered in a mortar until all of it 
 will pass through a sieve of 20 meshes to the inch. It 
 is not sufficient to discontinue the grinding when 
 enough has been obtained to furnish 10 or 20 grammes 
 for the infusion, but the whole 500 or 1000 grammes 
 must be ground, sieved, and then thoroughly mixed 
 before proceeding, since the first portion ground is 
 much softer than that reduced last, and therefore repre¬ 
 sents a different amount of tannin. After all has been 
 ground, sieved, and thoroughly mixed, 5 grammes of 
 galls, 10 grammes of sumac, valonia, or myrobalans, 
 or 20 grammes of bark are boiled for one-half hour 
 with 500 cc. of water, strained into a litre flask, and 
 washed and pressed with sufficient water to bring the 
 measure of the infusion to one litre. 
 
DETECTION AND ESTIMATION OF TANNINS. 45 
 
 As glass is liable to fracture in the above boiling, a 
 kettle of what is known in this country as “agate¬ 
 ware” has been found very satisfactory. The infusion 
 may also be prepared in an apparatus described by 
 Yon Schroder (Fig. 1), which consists of a cylindrical 
 
 Fig. 1. 
 
 cast-tin vessel 12.5 cm. high and 7 cm. in diameter, 
 with a spout but no handle; the latter is omitted in 
 order that the vessel may be more readily heated in a 
 water-bath. Accompanying this is a strainer or plunger 
 of the same metal, with a handle about 16 cm. in length. 
 The strainer is of such diameter that when covered 
 with muslin it will just fit the inside of the cylindrical 
 vessel and play the part of a piston to it. Five, ten, 
 or twenty grammes of the powdered material are placed 
 in the vessel, 200 cc. of cold distilled water added, and, 
 
46 
 
 THE TANNIN, S’. 
 
 after macerating for one hour, the strainer is pressed 
 into the cylinder and the solution poured into a litre 
 flask. The strainer is then drawn up, and, without re¬ 
 moving it, 200 cc. of hot distilled water are poured in 
 so as to wash the liquid and powder adhering to the 
 strainer down into the vessel, which is immediately 
 set in a water-bath and heated for one-half hour, the 
 strainer pressed down, and the solution poured into 
 the litre flask. This operation of hot extraction is 
 continued until 1000 cc. of infusion are obtained; it 
 is then allowed to cool, cold water is added to bring 
 the solution again up to the mark, and the whole is 
 filtered. The tannin strength of the solution should 
 be such that 10 cc. will not reduce more than 8 cc. of 
 permanganate solution. 
 
 It is sometimes desirable to distinguish between the 
 easily soluble tannin and the difficultly soluble tannin. 
 That which dissolves in cold water is accepted as rep¬ 
 resenting the former, while that which is afterwards re¬ 
 moved by hot water represents the latter. The infusion 
 of these may be prepared by extracting in the Von 
 Schroder apparatus with cold water until one litre is 
 obtained, and then preparing a litre of the hot infusion 
 from the residual material. 
 
 It was suggested by the Commission to employ a 
 Heals press for the cold extraction of the tannin ma¬ 
 terial. This consists of a closed cylindrical percolator 
 of metal so arranged as to allow the water to be applied 
 under the pressure of a column one and one-half metres 
 in height. 
 
 The accompanying illustration (Fig. 2) is of an ap¬ 
 paratus which may be constructed in any laboratory, 
 
DETECTION AND ESTIMATION OF TANNINS. 
 
 47 
 
 Fig. 2. 
 
48 
 
 THE TANNINS. 
 
 and will accomplish the purpose under any reasonable 
 height of water column. This consists of a glass per¬ 
 colator, A, fitted with a stopcock, C, at the lower end, 
 and with a tightly-fitting rubber stopper, D, at the top; 
 to a glass tube in this cork is attached a rubber tube, 
 E, of any desired length, and connected with a small 
 reservoir, that is arranged to be placed at variable 
 heights above the percolator, and at the lower orifice of 
 the latter is placed the litre flask B. The sample is 
 packed in A and cold distilled water run on until it 
 begins to drop from the lower end, the stopcock C 
 is then closed, and under a pressure of a column of 
 water one and one-half metres in height it is allowed to 
 macerate for from twelve to sixteen hours; the stopcock 
 is then opened, and the percolation allowed to proceed 
 until one litre of liquid is obtained. The liquid should 
 not be allowed to come from the percolator faster than 
 in drops, and to obtain one litre should require from 
 three to four hours. It is just as well to have a pinch- 
 cock attached to the rubber tube E to assist in control¬ 
 ling the flow of liquid. When the desired amount of 
 cold infusion lias been obtained, the residue is extracted 
 with hot water in a Yon Schroder apparatus or any 
 other convenient vessel in order to obtain one litre of 
 the hot infusion. 
 
 THE ASSAY OF THE TANNIN INFUSION. 
 
 For this part of the operation the following appa¬ 
 ratus and chemicals are required. 
 
 1. Permanganate Solution .—Ten grammes of pure 
 potassium permanganate are dissolved in 6 litres of 
 water. 
 
DETECTION AND ESTIMATION OF TANNINS. 49 
 
 2. Indigo Solution .—A solution of 30 grammes of 
 sodium sulphindigotate (“ Carminum coerul. opt., pure 
 Indigotin I. of Gehe and Co.,” Dresden) in 3 litres of 
 dilute sulphuric acid (1 volume of the acid to 3 volumes 
 of water). This is agitated for some time, filtered, and 
 sufficient water added through the filter to make 6 
 litres. The value of this solution should be such that 
 20 cc. in 750 cc. water should require about 10.7 cc. 
 of the above permauganate solution to decolorize it. 
 
 3. Hide Powder .—This must be white and woolly 
 in character, and not yield to cold distilled water any 
 substance capable of reducing permanganate. Such a 
 powder is prepared by Dr. Roth, of Berlin, and by 
 the Vienna Research Station, and can usually be had 
 of importers and dealers in chemicals throughout the 
 world. 
 
 4. Standardizing the Permanganate Solution .—The 
 purest obtainable tannin (that of Schering was recom¬ 
 mended by the Commission) is used for the standard. 
 For this purpose a portion is dried at 100° to constant 
 weight, then such a quantity of the air-dried substance 
 as to represent 2 grammes of it in the dried condition 
 is taken and dissolved in one litre of water. 
 
 10 cc. of this solution and 20 cc. of the indigo solu¬ 
 tion are added to 750 cc. of water, and the permanganate 
 solution is run in from a graduated burette with constant 
 stirring until the liquid assumes a greenish color, and 
 then more cautiously, a drop or two at a time, until a 
 pure yellow color with a pinkish rim is reached, which is 
 most apparent on the shaded side. 50 cc. of the tannin 
 solution are then macerated with 3 grammes of hide 
 powder (which has been previously well moistened and 
 
 5 
 
50 
 
 THE TANNINS. 
 
 squeezed out) for eighteen or twenty hours with frequent 
 agitation, filtered, and 10 cc., with 20 cc. of indigo solu¬ 
 tion in 750 cc. of water, titrated with the permanganate 
 as before. The difference between the amount of per¬ 
 manganate in the first and second titrations represents 
 the tannin or oxidizable matter removed by hide. The 
 “ not tannin,” or oxidizable matter not removed by 
 hide, should not much exceed 5 per cent. 
 
 The titration is best carried out in a porcelain dish, 
 although a beaker-glass on a white surface may be 
 used. 
 
 Having the value of the permanganate in tannin, we 
 next take the infusion prepared as previously described 
 and carry out the titration Avith permanganate and 
 treatment with hide on it, by using 10 cc. of the infu¬ 
 sion, 20 cc. of the indigo solution, and 750 cc. of 
 water. After obtaining the permanganate value of 
 this infusion, 50 cc. more of the latter are agitated for 
 from sixteen to eighteen hours Avith 3 grammes of hide 
 poAvder as before, and 10 cc. of the filtrate titrated in 
 the presence of 20 cc. of the indigo solution and 750 
 cc. ot water. From these data it is easy to calculate 
 the percentage of tannin in the material from which the 
 infusion was made. 
 
 Yon Schroder found by the use of Hammer’s 
 method that the pure tannin does not represent the 
 full value of the tanning material, and suggested that 
 the tannin found be multiplied by 1.05. 
 
 Neubauer used animal charcoal instead of hide 
 powder for absorbing the tannin ; it has been found, 
 hoAvever, to absorb other substances than tannin in con¬ 
 siderable quantity. 
 
DETECTION AND ESTIMATION OF TANNINS. 51 
 
 Lowentlial used a solution of gelatin instead of hide 
 powder. This solution was prepared by taking 20 
 grammes of good gelatin, allowing it to swell for several 
 hours in cold water, then dissolving with the aid of heat 
 and more water, saturating the solution with common 
 salt, adding 100 cc. of hydrochloric acid and sufficient 
 water to make one litre. The infusion after agitation 
 for some time with the gelatin solution was found to 
 filter slowly, and Procter suggested stirring in about 5 
 grammes of finely-powdered kaolin for causing a rapid 
 settling of the precipitate and so giving a solution which 
 filtered rapidly and clear. 
 
 Simaud recommended the bone tissue previously de¬ 
 scribed. 
 
 Many more details and numerous suggestions of 
 minor importance might be added, but they would 
 serve rather to complicate the process given. To 
 those who wish to study the original papers on tannin 
 estimation more in detail, the following are recom¬ 
 mended : Gauhe, Cecil, Lowentlial, Neubauer, Procter, 
 Notzli, and the Report of the Commission of German 
 chemists. 
 
SECTION I. 
 
 SOURCES. 
 
 By the puncture of a small insect, the Cynips Galina 
 tinotorise, on the young buds of the small twigs of 
 Quercus lusitanica, variety infectoria , there are depos¬ 
 ited ova, around each of which rapidly forms a mass 
 that in its perfected state becomes the gall, oak-gall, or 
 nutgall of commerce. The small tree or shrub which 
 furnishes these galls grows chiefly in Asia Minor and 
 some of the other regions surrounding the Mediter¬ 
 ranean Sea. 
 
 The early history of galls is conveniently assigned 
 to the ancients. Hippocrates administered them me¬ 
 dicinally, and from the earliest times they were resorted 
 to as a means of staining the hair black. Theophras¬ 
 tus, Dioscorides, Pliny, and other writers mention the 
 superiority of the galls from Syria. 
 
 The most esteemed galls at the present time are those 
 collected in Mesopotamia and shipped from Bombay 
 to London. They are known in commerce as Levant 
 galls. The best-known variety in this country comes 
 under the name of Aleppo or Turkish galls. They are 
 collected in the surrounding districts and taken to 
 Smyrna, where they are sorted and shipped to various 
 
 55 
 
56 
 
 THE TANNINS. 
 
 parts of the world. Poorer varieties are shipped from 
 some other Mediterranean ports. 
 
 Galls are nearly globular, from ten to twenty milli¬ 
 metres in diameter, tapering slightly towards the base, 
 the lower half being smooth, while the upper portion 
 is usually covered with numerous bluntly-pointed tu- 
 bercules. The best galls are gathered before the insect 
 has matured; if left until after this development has 
 occurred, there is found about half-way between the 
 stem and summit a small hole, from which the devel¬ 
 oped insect has escaped; at this period they are found 
 to be deficient in tannin, and therefore become the green 
 or white variety. Those collected at the proper time 
 are heavy, somewhat brittle, breaking with a slightly 
 resinous fracture, exhibiting the larva in a small cavity 
 at the centre, while the surrounding tissue frequently 
 appears as a radiating structure. Internally galls are 
 deep greenish yellow, without odor, of a slightly acid 
 and very astringent taste with a faintly sweetish after¬ 
 taste. 
 
 When Scheele in 1786 discovered gallic acid he sup¬ 
 posed it to be the most important constituent; Chevreul 
 afterwards found ellagic acid; then Scheele produced 
 pyrogallic acid, and supposed it identical with > gallic 
 acid, but much purer, on account of having been sub¬ 
 limed ; then followed the work of Dize, Deyeux, Se- 
 guin, and Proust, as stated in the preceding general 
 history. 
 
 After the existence of tannic acid was well estab¬ 
 lished, Davy in 1803 appears to have been the first 
 to make an analysis of nutgalls, with the following 
 result: 
 
SOURCES. 
 
 57 
 
 Tannic acid. 26.00 per cent. 
 
 Gallic acid. 6.20 “ 
 
 Gum and insoluble tannin . . . 2.40 “ 
 
 Calcium and other salts. 2.40 “ 
 
 Woody fibre. 63.00 “ 
 
 100.00 “ 
 
 These figures indicate either that the quality of the 
 galls was poor, or, more probably, that the methods in 
 use at that time were defective. 
 
 A more recent analysis was made in 1845 by Guibourt, 
 with the following result: 
 
 Tannic acid. 65.00 per cent. 
 
 Gallic acid. 2.00 “ 
 
 Ellagic and luteo-gallic acids ... 2.00 “ 
 
 Chlorophyll. 0.70 
 
 Brown alcoholic extract. 2.50 “ 
 
 Gum. 2.50 “ 
 
 Starch. 2.00 “ 
 
 Cellulose. 10.50 “ 
 
 Sugar, albumen. 
 
 Sulphate of potassium .... 
 
 Chloride of potassium .... 
 
 Gallate of potassium.i- 1.30 “ 
 
 Gallate of calcium. 
 
 Oxalate of calcium. 
 
 Phosphate of calcium . . . . , 
 
 Water. 11.50 “ 
 
 100.00 “ 
 
 These results have been generally accepted, and are 
 universally quoted in text-books, as no chemist since 
 then has attempted such a detailed analysis. It may 
 with reason be doubted if an analysis at the present 
 time would agree in all points with this one. 
 
 A still more recent, although not intended to be so 
 
58 
 
 THE TANNINS. 
 
 complete an examination was made in 1869 by Wat¬ 
 son Smith, for the purpose of comparing English and 
 Aleppo galls: 
 
 Tannic acid. 61.65 per cent. 
 
 Gallic acid. 1.60 11 
 
 Woody fibre. 15.68 “ 
 
 Water. 12.32 “ 
 
 Coloring-matter and loss. 8.75 £l 
 
 100.00 “ 
 
 Another variety of galls, which for some purposes 
 rivals the Turkish in importance, is that from China. 
 These are formed by an insect, Aphis Ghinensis, on 
 the leaf-stalks and young branches of Rhus semia- 
 lata, a tree from ten to fifteen metres in height, in¬ 
 digenous to North India, China, and Japan. Chinese 
 galls are hollow, from two and a half to four centime¬ 
 tres in length and half that measure in breadth. They 
 are frequently quite irregular in shape, with horn-like 
 projections. The shell, which constitutes the material 
 part, is thin and brittle, breaking with a resinous frac¬ 
 ture. The external surface is grayish or mouse-colored 
 and covered with a fine velvety pubescence. 
 
 Closely allied to these are the Japanese galls, which 
 are so similar as to lead one to believe they are the 
 same. They have, however, been assigned by Siebold 
 to Rhus Japonica and by Murray to Rhus javccnica. 
 Being more deeply lobed than the Chinese variety, they 
 are consequently more irregular in form. 
 
 Although the Japanese galls are preferred by some, 
 the two varieties are usually employed indiscriminately. 
 Large quantities of both under the name of Chinese 
 
SOURCES. 
 
 59 
 
 galls are used in Germany and the United States for 
 the manufacture of tannic acid, of which they contain 
 about 70 per cent. They were received in Europe as 
 early as 1817, when they were analyzed by Brande, 
 who stated that they yielded to cold distilled water 75 
 per cent., and to alcohol the residue gave an additional 
 4 per cent., leaving 21 per cent, of woody fibre. 
 
 It was not until 1844 that these galls were recog¬ 
 nized to be of any value, so that our knowledge of their 
 constituents dates from that time. The Japanese va¬ 
 riety was first brought prominently to notice at the 
 Paris Exposition in 1878. 
 
 W. Stein in 1849, under the name of a new kind of 
 galls, described the Chinese variety as having the odor 
 of tobacco and yielding 2 per cent, of ash, consisting 
 of potassium, magnesium, calcium, and iron combined 
 with phosphoric, silicic, and carbonic acids and chlorine. 
 The other constituents were given as follows : 
 
 Tannic acid. 
 
 
 Other tannins. 
 
 .... 4.00 
 
 u 
 
 Saponifiable fat. 
 
 .... 1.00 
 
 a 
 
 Starch. 
 
 .... 8.00 
 
 it 
 
 Wood fibre. 
 
 .... 5.00 
 
 a 
 
 Inert material. 
 
 .... 13.00 
 
 a 
 
 
 100.00 
 
 a 
 
 L. P. Bley in 1850 found that ether dissolved 76 
 per cent., that moisture amounted to 8 per cent., and 
 that the ash was alkaline, nearly free from calcium salts, 
 but rich in potassium and phosphoric acid. Buchner 
 in 1851 stated that ether-alcohol extracted 74.35 per 
 cent., while Leconnet obtained by maceration with ether 
 66.66 per cent. 
 
60 
 
 THE TANNINS. 
 
 Buchner considered the tannin identical with that 
 of oak-bark. In comparison with the above he found 
 that Aleppo galls gave to 
 
 77.00 percent, of extract. 
 80.40 “ “ 
 
 86.50 “ “ 
 
 Ether . . . 
 Ether-alcohol 
 Cold water . 
 
 Under the commercial name of “ Chinese pear-galls/’ 
 Hartwich in 1875 described a species of galls, which 
 he found to contain 72 per cent, of tannin. He was 
 unable to ascertain the botanical source, but they prob¬ 
 ably belonged to one of the above varieties. 
 
 A number of other varieties of galls have been ana¬ 
 lyzed and described from time to time ; their use, how¬ 
 ever, has usually been confined to the locality in which 
 they grow. 
 
 Among these may be mentioned the Bassorah, Bur- 
 mah, or Mecca galls, which were analyzed by L. F. 
 Bley in 1853, with the following results: 
 
 Tannic acid. 26.00 per cent. 
 
 Gallic acid. 1-60 “ 
 
 Fatty oil. 0.60 “ 
 
 Kesin. 3.40 “ 
 
 Extractive and salts. 2.00 “ 
 
 Starch. 8.40 
 
 Woody fibre. 46.00 “ 
 
 Moisture . 12.00 “ 
 
 100.00 
 
 They were described as reddish-brown in color, from 
 the size of a hazel-nut to that of a small apple. They 
 were believed to be produced on the Quercus tinctoria 
 by the sting of Oynips isana, and by Lambert were 
 
SOURCES. 
 
 61 
 
 considered identical with the u Sodom Apple” of the 
 ancient writers. They were used in the Orient in the 
 process of dyeing Turkey red. 
 
 Piedmontese galls are developed on the acorns of 
 Quercus pedunculata, Quercus sessiliflora, and some 
 other species, by the sting of the Cynips Quercus-ccily- 
 cis. They arc known as lcnoppern or acorn-galls. These 
 galls, which are of the size of a hazel-nut to that of a 
 walnut, are collected in the large forests of Austria- 
 Hungary from August to October, and are brought into 
 commerce partly whole, partly in the powdered condi¬ 
 tion, and are either used directly in one of these forms 
 or are converted into extract. They contain about 45 
 per cent, of tannic acid, which, according to Lowe, is « 
 identical with that obtained from other galls. Some 
 authorities give 20 per cent., others 50 per cent., as the 
 tannin strength of these acorn-galls, and, no doubt, 
 they vary greatly in value according to the time of 
 collection. They are largely used by the tanners 
 throughout Austria, 
 
 The German galls are produced on the twigs of Quer¬ 
 cus robur, and are probably identical with the English 
 galls analyzed by Watson Smith in 1869, with the fol¬ 
 lowing results: 
 
 Tannic acicl . 26.71 per cent. 
 
 G-allic acid. traces only. 
 
 Woody fibre. 47.88 per cent. 
 
 Moisture. 20.61 “ 
 
 Coloring and loss. 4.80 “ 
 
 100.00 “ 
 
 They were obtained directly from Cheshire, and the 
 author suggested that the absence of gallic acid was 
 
 6 
 
62 
 
 THE TANNINS. 
 
 due to their having been analyzed while in the fresh 
 condition. 
 
 French galls, from Quercus ilex, are round, hard, 
 light, reddish-brown, and related to the Burgundian 
 galls from Quercus cerris, from which are also pro¬ 
 duced the Greek as well as the Italian galls. The 
 commercial name of Trieste galls is usually applied to 
 those from Q. cerris. Istrian galls are very small, 
 light, pale yellow in color, and contain 24 per cent, of 
 tannic acid. Hungarian galls, from Q. Austriaca, are 
 characterized by being covered with wart-like protu¬ 
 berances. 
 
 Pistacia galls are produced on the plants of a genus 
 , of that name, belonging to the same natural order as 
 the Rhus. Guibourt described one variety, produced 
 on a plant of the genus Terebinthus, as a flattened ves¬ 
 icle enlarged in the middle and tapering to a point at 
 each end, seven centimetres long and seventeen milli¬ 
 metres broad, with a very astringent taste and an odor 
 resembling Ohio turpentine. Another variety pro¬ 
 duced on the pistacia was described as from four to six 
 centimetres in length and eight to fifteen millimetres in 
 breadth, terminating by a sharp point. The taste was 
 described as simply mucilaginous and aromatic without 
 astringency. 
 
 Tamarisk galls were described by Holmes as of the 
 size of a pea to that of a bean, and containing 40 pei*- 
 per cent, of tannic acid. Those from Morocco are pro¬ 
 duced on Tamarix articulata. In India similar galls 
 are produced on T. Gallica and T. orientalis. They are 
 much used by the natives medicinally. 
 
 Numerous varieties of galls have been noticed in the 
 
SOURCES. 
 
 63 
 
 United States, one from Texas on the Q. virens, or live- 
 oak, is said to closely resemble Aleppo galls, and to 
 contain 40 per cent, of tannic acid. Another variety, 
 from California, formed on Q. lobata, is soft and 
 spongy but very astringent. 
 
 Dr. Squibb in 1873 stated that American galls from 
 oak and sumac have been found valuable sources for 
 gallic acid. 
 
 In 1890 galls collected in the vicinity of Philadel¬ 
 phia by the author from the leaves of Q. alba in the 
 month of July, and identified by Mr. L. O. Howard, 
 entomologist of the United States Department of Agri¬ 
 culture, as having been produced by the insect Acraspis 
 erinacei, were found to contain 17.89 per cent, of tan¬ 
 nic acid. The moisture was found to be 45.95 per cent., 
 and ash 0.60 per cent. These galls are found most 
 abundantly on the young white oaks, and may be recog¬ 
 nized by their covering of purple spines. Another 
 variety collected in August from the twigs of the same 
 oak, and identified by Mr. Howard as “a Dipterous gall 
 made by some species of Cecidomyia or Diplosis” was 
 found to contain as an average of three estimations 
 9.34 per cent, tannic acid, 73.19 per cent, of moisture, 
 and 0.46 per cent, of asli. The same variety rapidly 
 dried by artificial heat at about 80°, so as to destroy 
 the insect, yielded 31.68 per cent, of tannin, 11.34 per 
 cent, of moisture, and 2.6 per cent, of ash. Another 
 variety, also collected in August, from the leaves of Q. 
 palustris , and stated by Mr. Howard to have been pro¬ 
 duced by Holcarpis globulus, Fitch, gave 3.91 per cent, 
 tannic acid, 58.73 per cent, moisture, and 0.77 per cent, 
 ash. 
 
64 
 
 THE TANNINS. 
 
 An unidentified variety, collected from the leaves of 
 Rhus glabra, and in many respects the counterpart of 
 the Chinese galls, was allowed to become air-dried, and 
 then found to contain 61.70 per cent, of tannic acid, 
 12.93 per cent, of moisture, and 2.04 per cent, of ash. 
 Some previous experience has shown that the white-oak 
 galls if allowed to become air-dried lose their tannic 
 acid, presumably by the development of the insect, so 
 that, to determine the tannin value, either the galls in 
 the moist state must be employed, or they must be sub¬ 
 jected to sufficient artificial heat to destroy the insect. 
 
SECTION II. 
 
 HISTORY. 
 
 While the general history in a preceding section 
 refers largely to this member of the class, it is found 
 necessary now to treat the history of each tannin sep¬ 
 arately, beginning with 1802, when Proust made the 
 statement that there were many different kinds of 
 tannin. 
 
 Davy published in 1803 the results of two years’ 
 labor on the subject, which was prefaced by some his¬ 
 torical remarks, in which he, like Ivarsten, attributed 
 the discovery of tannin to Seguin, although he called 
 attention to the fact that Diz6 first noticed the precipi¬ 
 tate caused by the addition of sulphuric acid to infusion 
 of galls. He further reviewed the work of Deyeux 
 and Proust, giving the former much credit for his 
 “able memoir,” but to the claim of the latter, “that 
 there exist different species of the-tanning principle, 
 possessed of different properties and different powers 
 of acting upon reagents, but all precipitable by gelatin,” 
 he answered, that, while probable, it could “ not be 
 considered settled until the tannin in the different vege¬ 
 tables has been examined in its pure and isolated state.” 
 He did not accept all of Seguin’s theories about the 
 action of infusion of galls on animal membrane, and 
 considered them unwarranted by facts. 
 
 Thus far the papers quoted confined themselves to 
 6* 65 
 
66 
 
 THE TANNINS. 
 
 the history and discovery of tannin ; therefore it is 
 not surprising that in 1804 we find a contribution by 
 Trommsdorff on the nature of this astringent principle 
 in galls. His investigations somewhat resembled those 
 of Deyeux. The work was divided into fifty-five ex¬ 
 periments, in which he studied the precipitates caused 
 by hydrochloric and sulphuric acids on infusion of galls, 
 and added the observation that acetic and phosphoric 
 acids likewise caused precipitates with tannin, while 
 oxalic, tartaric, and malic acids caused no precipitates. 
 He noticed the effect of tannin solution, after removal 
 of gallic acid, on litmus-paper, and further endeavored 
 to obtain pure tannin by Proust’s method of precipi¬ 
 tation with potassium bicarbonate, but found much tan¬ 
 nin in the filtrate, and finally concluded that the pre¬ 
 cipitate contained calcium and that Proust erred in his 
 new method. The same conclusions were reached in 
 regard to Proust’s other methods by precipitation with 
 mineral acids. This long, and at that time valuable, 
 series of experiments was abruptly terminated without 
 drawing conclusions, as he hoped to continue his inves¬ 
 tigations. 
 
 After the above communication no important results 
 are recorded until Serturner, an apothecary in Eim- 
 beck, during the year 1812, published his experiments, 
 in which he established the absence of nitrogen, and 
 made some observations on the action of alkalies on 
 tannin, and the change into gallic acid. As, however, 
 his results were in part a repetition of those obtained 
 by previous investigators, his work was not kindly 
 criticised by Gehlen. 
 
 While there were a number of contributions on this 
 
HISTORY, 
 
 67 
 
 subject from year to year, nothing stands out promi¬ 
 nently until the work of Berzelius in 1827, which ap¬ 
 peared in the Jahresbericht and in his text-book. After 
 remarking that every investigator offered a new method 
 of preparation, he proposed two of his own, one by 
 precipitating a clear infusion of nutgalls with sulphuric 
 acid, and the other by a similar precipitation with po¬ 
 tassium carbonate. At that time there was no distinc¬ 
 tion between the tannin of the uutgall and that from 
 the oak-bark, since both are described as “ Eichen- 
 Gerbstoff ” and further he stated that the “ entire oak 
 genus contains a tannin which appears to be identical.” 
 The change of tannin into gallic acid had not been 
 fully investigated at that time ; Berzelius observed that 
 the question is whether gallic acid is formed by the 
 destruction of tannin, or whether it results from the 
 setting free of a substance with which it was in combi- 
 nation. He used the classification depending on the 
 color with iron salts, and described as giving a blue 
 color the oak, sumac, alder, birch, and a few others, and 
 as producing a green color that of cinchona, catechu, 
 kino, fir, and pine. He also reported what was prob¬ 
 ably the first determination of the ultimate composition 
 of tannin. The lead salt was used, and his conclusion 
 was that C 18 H 18 0 12 most nearly represented the formula 
 of tannin. 
 
 This work of Berzelius is full of historical data, and 
 many of his results are as true to-day as at that time. 
 He gave the credit of discovery to Deyeux in the fol¬ 
 lowing language: “ The operation of tanning was 
 
 known to the ancients, but the substance which com¬ 
 bined with the hide was first noticed by Deyeux, and 
 
68 
 
 THE TANNINS. 
 
 afterwards with more exactness investigated by Seguin. 
 Proust endeavored to discover a method of separation.” 
 
 In 1832, Geiger, by a series of investigations on tan¬ 
 nin and the action of that substance on iron salts, came 
 to the following conclusions : (1) All tannins are iden¬ 
 tical, (2) the iron-green tannins become iron-black if 
 the free acid present be neutralized by an alkali or by 
 iron, and (3) the iron-black tannins by the addition of 
 some acid, especially tartaric, become iron-green. Ber¬ 
 zelius, however, did not accept this, and he stated in 
 his Jahresbericht that he too had noticed this peculiarity 
 of the tannins with iron salts under different circum¬ 
 stances, but attributed it to a play of colors, since by 
 standing a black precipitate separated. 
 
 In Buchner’s Repertorium fur die Pharmacie, 46 , 
 316, 1833, we find a review of a prize essay by A. W. 
 Buchner on the subject of “ The most Eecent Discov¬ 
 eries on lannic Acid or the so-called Tannin (Gerb- 
 stoff).” This was written in answer to the following 
 questions, offered in 1824 by the Harlem Royal 
 Academy of Natural Sciences : 
 
 u Is the so-called tannin, which we extract from dif¬ 
 ferent plants, a true principle, or have we given this 
 name to different plant principles which possess the 
 general properties of astringency and of forming 
 leather ? 
 
 • A 
 
 ‘‘By what means can we best extract these substances 
 from the various plants in a state of purity, and how 
 determine that they are unmixed and distinct? 
 
 “ Which is the best and most ready method for pre¬ 
 paring tanning materials from the charcoal of indigo 
 and other vegetable substances with acid, and how 
 
HISTORY. 
 
 69 
 
 far is this artificially prepared tannin distinguishable 
 from the natural? Are not the two identical sub¬ 
 stances ? 
 
 “ In case of arriving at a fuller knowledge of the 
 different tanning substances, to what use are the various 
 ones best adapted in tanning and manufacturing as well 
 as in medicine?” 
 
 While the answers to these questions are full of in¬ 
 terest, it is impossible to see that the knowledge of the 
 subject was very materially advanced by the writer. 
 Some of the questions are still unsolved. 
 
 The next important work was in 1834, when a me¬ 
 moir was presented to the Institute of France by Pe- 
 louze, which memoir was widely copied and appears to 
 have caused a general awakening among the scientists 
 of that day to a closer investigation of this almost 
 dormant subject. 
 
 Probably the most important part of Pelouze’s me¬ 
 moir was the new method proposed for preparing tan¬ 
 nin. This process is the one usually quoted in the text¬ 
 books at the present day, and is well adapted for the 
 extraction of the tannin from a substance as rich in it 
 as nutgalls. 
 
 Briefly, it consists in extracting galls with ether con¬ 
 taining some alcohol and water. The solution separates 
 in^.o two layers, the upper an ethereal one of gallic acid 
 with some tannin, the lower an aqueous solution of 
 tannin containing some ether. This aqueous solution 
 on evaporation leaves a porous mass of tannin, which 
 Pelouze claimed was quite pure. 
 
 This substance gave on drying at 120° the following 
 percentage composition : 
 
70 
 
 THE TANNINS. 
 
 I. II. III. IV. 
 
 C. 51.77 51.56 51.20 51.72 
 
 H. 3.98 4.37 4.29 4.17 
 
 O. 44.25 44.07 44.51 44.11 
 
 100.00 100.00 100.00 100.00 
 
 These figures, lie stated, closely agreed with those 
 obtained by Berzelius and indicated the formula 
 Ci 8 H 18 0 12 . 
 
 The remainder of the memoir was devoted to show¬ 
 ing the acid properties of the tannin and its capability 
 to form definite salts with the different bases. He 
 further stated that gallic acid did not pre-exist in the 
 galls, but that it was a product of atmospheric action 
 on tannin, that at a temperature of 215° it was trans¬ 
 formed into pyrogallic acid and carbon dioxide, and 
 that pyrogallic acid in turn was converted into meta¬ 
 gallic acid and water. This appears to have been the 
 first statement, based on experiment, that tannin be¬ 
 comes converted into gallic acid through the influence 
 of atmospheric oxygen. 
 
 This work of Pelouze attracted general attention to 
 the subject, and in the same year Liebig published his 
 results on an elementary analysis in which he found: 
 
 C. 52.50 
 
 H. 4.12 
 
 O. 43.38 
 
 100.00 
 
 and concluded that C 18 H 16 0 12 more closely represented 
 the formula. This he communicated to Pelouze, who 
 undertook anew the analysis, obtaining the following 
 percentage composition : 
 
HISTORY. 71 
 
 
 I. 
 
 II. 
 
 c. 
 
 . 51.30 
 
 51.36 
 
 H. 
 
 . 3.83 
 
 3.76 
 
 0. 
 
 
 44.88 
 
 
 100.00 
 
 100.00 
 
 These results he shortly after sent in a letter to Liebig, 
 in which he stated that, while the difference was very 
 slight, he was inclined to accept the latter’s formula 
 of C 18 H 16 0 12 , in which view Dumas concurred. With 
 some unimportant reservations Berzelius, in his Jahres- 
 bericht, 1840, accepted this formula also. 
 
 In 1836, Leconnet suggested another method for pre¬ 
 paring tannin, by stirring finely-powdered galls with 
 sufficient ether to make a thin mixture, and allowing 
 to stand twenty-four hours. The mass was then pressed 
 between strong linen, this process was repeated with 
 more ether, and the syrupy liquid evaporated. He 
 claimed a larger yield (40 to 60 per cent.) than that 
 obtained by Pelouze, with the use of much less ether. 
 
 Robiquet about this time directed his attention to the 
 decomposition of tannin with the formation of gallic 
 acid. Contrary to the observations of Pelouze, he 
 found that the change to gallic acid would take place 
 without access of air or oxygen, but found it was caused 
 by a ferment in the galls. These observations were 
 confirmed by Larocque in 1841. 
 
 Previous to the investigations of Stenhouse in 1842, 
 such authorities as Pelouze, Berzelius, and Liebig con¬ 
 sidered the tannins from all sources to be identical, 
 differing only in purity. Although Proust had stated 
 forty years before that there probably existed “ several 
 different species of the tanning principle,” Stenhouse 
 
72 
 
 THE TANNINS. 
 
 was the.first to prove this by experiment. In all the 
 writings to this time the term “ gallotannic acid” was 
 applied to that from oak bark or wood as well as that 
 from galls. Stenhouse, by adopting a method used at 
 the present time to study the tannins,—namely, by 
 heating to decomposition,—found the oak-bark tan¬ 
 nin yielded no pyrogallol. The only substance yield¬ 
 ing true gallotannic acid was found to be sumac, and 
 this, so far as the sumac is concerned, has never been 
 disproved. He also showed by experiment that there 
 was a distinction between the tannins which produced 
 a blue and those which produced a green precipitate 
 with iron salts, thereby contradicting several previous 
 investigators, as well as the expressed opinion of Ber¬ 
 zelius. The subject of iron-bluing and iron-greening 
 tannins attracted considerable attention about this time, 
 and several other chemists devoted their energies to 
 solving the problem of classification by this means, but 
 with indifferent success. 
 
 The work of Domine in 1844 has been very exten¬ 
 sively quoted, because he offered some improvements 
 on the method of Leconnet for preparing tannin. He 
 claimed that alcohol was an unnecessary constituent of 
 the ether used in extracting galls, but that the presence 
 of a small quantity of water was very essential. The 
 method proposed was to allow the galls to become sat¬ 
 urated with the damp atmosphere of a cellar by expo¬ 
 sure of some days, then mix with sufficient ether to 
 make a paste, and express, this expression to be re¬ 
 peated with ether which had been shaken with six per 
 cent, of water. This process was at one time adopted 
 by both the United States and British Pharmacopoeias. 
 
HISTORY. 
 
 73 
 
 From this time those who worked with tannin busied 
 themselves with attempting to arrive at its constitution 
 as well as its composition ; Liebig’s formula, C 18 H 16 0 12 , 
 did not convey a sufficiently satisfactory idea of what 
 relation tannin bore to other allied compounds, espe¬ 
 cially to gallic and pyrogallic acids. 
 
 A few investigators stand out prominently. Of 
 these Wether ill first carefully investigated the conver¬ 
 sion of tannic into gallic acid, by boiling 50 grammes 
 of tannic acid with 500 cc. of a solution made by mix¬ 
 ing one volume of sulphuric acid, specific gravity 1.840, 
 with four volumes of water. He obtained from 100 
 parts of tannic acid 87.4 parts of gallic acid. 
 
 About the same time, 1847, Mulder made a valuable 
 contribution on the subject. The original being in 
 Dutch and in a publication not found in this country, 
 a full translation may be found in Buchner’s Reperto- 
 rium fur die Pharmacie, 101 , 311, and Erdmann’s and 
 Marchand’s Journal , 17, 337. Berzelius, Jahresbericht, 
 1850, 224, gave a short abstract of it, and appended 
 some critical remarks of his own, which indicated that 
 he did not believe this work of Mulder in any way 
 superior to the great number of other publications on 
 the subject. 
 
 Mulder stated in the introductory remarks that the 
 formula of Liebig had been generally accepted, but that 
 he found it to be C 28 H 18 0 17 -j- H 2 0, which compactly 
 stated in our nomenclature is C 14 H 10 O 9 , or exactly that 
 which has been established by more recent investigators 
 and is accepted at the present time. This determina¬ 
 tion was made on tannic acid which had been dried at 
 120°. He gave much credit to Pelouze, and stated that 
 
 7 
 
74 
 
 THE TANNINS. 
 
 no better method of preparing the acid had since been 
 discovered. 
 
 After further reviewing the work of Pelouze on py- 
 rogallic and melangallic (metagallic) acids, he studied 
 the conversion of tannic into gallic acid by the action 
 of other acids; the action of alkalies on tannic, gallic, 
 and ellagic acids; the percentage composition of tannic 
 acid and its formula; the action of ammonia; and, 
 finally, some of the tannates, especially of lead. 
 
 With the exception of the work done by Liebig, it 
 is safe to say that this work of Mulder was the most 
 elaborate investigation after that of Pelouze, which in 
 many respects it resembled. 
 
 While there were about the year 1850 a number of 
 creditable publications, nothing is of great historical 
 value until we reach the work of Strecker in 1852 and 
 1854, which he carried out in Liebig’s laboratory. 
 These contributions are among the few that stand out 
 prominently, for, besides reviewing some of the work 
 of others, he detected the presence of sugar, as had been 
 previously indicated in Liebig’s revision of Geiger’s 
 Handbuch der Pharmacie, edition of 1843, page 854, 
 where it is stated that Braconnot found in the fermen¬ 
 tation of galls alcohol and carbon dioxide, which in¬ 
 dicated the presence of sugar, that had not been pre¬ 
 viously noted, and that tannic acid contained “the 
 elements of six atoms of gallic acid and one atom of 
 grape-sugar.” Strecker had noticed that by heating 
 tannic acid carefully a large carbon residue was ob¬ 
 tained, when it had been previously supposed that the 
 only decomposition products were pyrogallic acid and 
 carbon dioxide. He also obtained the reactions for 
 
HISTORY. 
 
 75 
 
 sugar in the solution remaining after converting tannic 
 into gallic acid, by treating this solution with acetate 
 of lead, filtering, removing the lead from the filtrate by 
 hydrogen sulphide, and applying potassium hydrate and 
 copper sulphate, whereby he obtained the reduction to 
 cuprous oxide. This he attributed to the presence of 
 sugar or a related carbohydrate. He further investi¬ 
 gated the elementary composition of tannic acid and 
 arrived at the formula C 40 H 36 O 26 , and he explained the 
 change into gallic acid and sugar as follows : 
 
 QtoH 36 0 26 + 10H 2 O = 2C 14 H 16 0 12 t c 12 h 24 o 12 . 
 
 These formulas were changed somewhat in his second 
 paper, two years later, when he arrived at the follow¬ 
 ing conclusions : 
 
 “ Tannic acid is a glucoside, and is split, through the 
 action of acids, alkalies, or ferments, into gallic acid 
 and glucose. 
 
 u The formula for tannic acid is C 54 H 44 0 34 , in which 
 three equivalents of water are replaced by metallic 
 oxides. The precipitate obtained by acting on tannic 
 acid solution with acetate of lead consists in great part 
 of a basic salt in which are contained ten equivalents 
 of lead oxide to one equivalent of tannic acid. 
 
 “The hitherto accepted compounds of tannic acid 
 with hydrochloric and sulphuric acids do not exist. 
 
 “ Gallic acid, C 14 H 12 O 10 , is, as tannic acid, a dibasic 
 acid. 
 
 “Other tannins are likewise glucosides, and contain 
 apparently also thirty-four equivalents of oxygen.” 
 
 The tannic acid used in these experiments was pre¬ 
 pared by Pelouze’s method, and purified in one case bv 
 
76 
 
 THE TANNINS. 
 
 dissolving in water and precipitating with ether, and in 
 another case by dissolving in ether and precipitating 
 with water. By these operations different layers were 
 obtained, the heaviest of which he considered the purest 
 and separated. These were then evaporated in vacuo 
 and heated to 125°. Seven different preparations gave, 
 when burned with copper oxide, closely agreeing results. 
 He offered, as further evidence of the glucosidal nature 
 of the acid, the fact that WetheriU obtained 87 per cent, 
 of gallic acid and he found 22 per cent, of glucose. 
 
 Robiquet in 1852 arrived at somewhat different con¬ 
 clusions, but these were not backed by such a mass of 
 experimental data as characterized Strecker’s. 
 
 The work of Strecker might be a fitting close to the 
 historical consideration, since the next important work 
 brings us to such a modern period that it may be more 
 properly studied under the properties and constitution 
 of the acid. 
 
 The authors, however, should be mentioned in this 
 connection ; therefore we must give to Julius Lowe and 
 Hugo Scliiff the credit of independently establishing 
 by careful research our present knowledge of tannic 
 acid. The former in 1867 first succeeded in reconvert¬ 
 ing gallic into tannic acid by treating barium gallate 
 with silver nitrate and obtaining a substance which 
 he described as precipitating gelatin and the alkaloids. 
 His work was taken up by Schiff in 1871 and carried 
 on for several years, and to this latter scientist we owe 
 our present knowledge of digallic acid. It is worthy 
 of note, however, as has been already stated, that most 
 discoveries are in a certain degree anticipated, and this 
 one of digallic acid was no exception, for Illasiwetz in 
 
HISTORY. 
 
 77 
 
 1867 announced that, “If tannin is not a glucoside, it 
 may perhaps be a digallic acid. The analyses of tan¬ 
 nin and its salts agree with this composition as well as 
 can be expected in the case of a substance which is so 
 difficult to purify.” 
 
 Lowe in 1872 contributed a paper on pure gallotan- 
 nic acid, in which he described a method of purification 
 by acetic ether, which will be more fully considered 
 under the appropriate head. 
 
 Notwithstanding the fact that most chemists at the 
 present time devote themselves to the study of what 
 may be termed artificial products, still those who have 
 contributed to the literature of tannic acid during the 
 last score of years could not be so much as mentioned 
 in this brief history. During the past decade much 
 time and earnest labor have been given to the endeavor 
 to discover a universal method of estimating not only 
 tannic acid but all tannins, and it is the intention that 
 each author shall receive his full share of credit in the 
 other parts of this work. 
 
 7 * 
 
SECTION III. 
 
 THE PREPARATION AND PURIFICATION OF TANNIC 
 ACID. 
 
 The separation of tannic acid in a nearly pure state 
 was first accomplished by Proust in 1798, by precipi¬ 
 tating the infusion of galls with stannous chloride, 
 separating the tin from the precipitate by hydrogen 
 sulphide, and evaporating the filtrate to dryness. This 
 method, with its variation by using lead acetate in 
 place of the tin salt, has done good service. The same 
 in a lesser degree may be said of the process proposed 
 by Berzelius, which consisted in precipitating the tan¬ 
 nic acid by sulphuric or hydrochloric acid, digesting 
 the precipitate, of tannic acid with the acid used, with 
 lead carbonate, filtering, and evaporating to dryness. 
 The above methods are not available for producing the 
 acid on a large scale; and that by precipitation with 
 hydrochloric or sulphuric acid is applicable only to 
 galls. 
 
 The numerous processes for obtaining tannic acid 
 from galls became practically valueless after Pelouze in 
 1834 published his method for obtaining the acid Iiy 
 percolating galls with ether. This method, which is 
 the one usually quoted in the text-books, consists in 
 percolating powdered galls with commercial ether 
 containing alcohol and water. 
 
 The details of the operation are to pack the powder 
 78 
 
THE PREPARATION OF TANNIC ACID. 79 
 
 in a cylindrical percolator, the upper end of which is 
 narrow in order that it may be stopped to prevent the 
 evaporation of the solvent. The lower end of the perco¬ 
 lator is plugged with cotton and connected with a flask, 
 ether is poured on the powder, and the ethereal solu¬ 
 tion of the galls allowed to collect. This solution soon 
 separates into two layers, the upper of which consists of 
 ether, gallic and ellagic acids, resin, and fat, with some 
 tannic acid, while the lower is a solution of moderately 
 pure tannic acid in water and ether. The percolation is 
 discontinued when the lower layer ceases to increase in 
 volume. The two layers are then separated, and the 
 lower one evaporated to dryness on a water-bath, by 
 which means the acid is obtained in a porous mass. 
 
 There have been, since the publication of this pro¬ 
 cess, numerous modifications of it suggested, but the 
 principle remains the same. The product is not abso¬ 
 lutely pure tannic acid, but a mixture of that compound 
 with gallic acid, coloring-matter, resin, and glucose. 
 It is, however, a process that is adapted to working 
 with large quantities, where there are facilities for 
 recovering the ether. 
 
 In order to obviate using so much ether, many 
 methods have been offered as superior to the above, 
 notably one by extracting with water and precipitating 
 with lead acetate. It is, however, a wasteful process 
 and is difficult and tedious to perform. 
 
 Mixtures of alcohol, ether, and water in various pro¬ 
 portions have been suggested for percolating galls, in¬ 
 stead of the commercial ether alone. Four parts of 
 ether and one part of alcohol have been recommended 
 as the most suitable solvent, although thirty parts ether 
 
80 
 
 THE TANNINS. 
 
 (specific gravity 0.740), four parts water, and one part 
 alcohol (90 per cent.) also make a good solvent. 
 Equally good is the United States Pharmacopoeia ether 
 (specific gravity 0.750), which is composed of seventy- 
 four parts ether and twenty-six parts alcohol with a 
 little water. Equal volumes of ether and alcohol have 
 been recommended on account of the increased yield 
 obtained; the product, however, is not so pure as that 
 from a more ethereal solvent. 
 
 In 1836, Leconuet proposed a method for extracting 
 tannic acid by mixing the powdered galls with suffi¬ 
 cient ether to make a paste, allowing the mixture to 
 macerate, then expressing through muslin, and repeat¬ 
 ing the process with more ether. The yield was found 
 to be 60 per cent., and a comparatively small quantity 
 of ether was employed. 
 
 The process as modified by Domine in 1844 was 
 adopted by the British and United States Pharmaco¬ 
 poeias. This modification consisted in first exposing 
 the powdered galls in a damp cellar for several days, 
 to allow the absorption of moisture, and then macer¬ 
 ating with commercial ether and expressing as in Lecon- 
 net’s process. 
 
 It has further been suggested to extract galls in such 
 a manner as to form three layers of the percolate. To 
 accomplish this, 10 parts of coarsely-powdered galls 
 are placed in a percolator and a mixture of 12 parts 
 stronger ether and 3 parts alcohol poured on, and the 
 mixture allowed to stand two days, when the percola¬ 
 tion is commenced and continued with the same mix¬ 
 ture of ether and alcohol until 10 parts are obtained. 
 The resulting percolate is mixed with one-third its 
 
THE PREPARATION OF TANNIC ACID. 81 
 
 volume of water, agitated well, and allowed to stand, 
 when it will be found that three layers have formed. 
 The under, watery layer contains nearly pure tannic 
 acid, and is evaporated rapidly in a vacuum, which 
 causes the acid to become porous. The upper layers 
 are distilled to recover the ether-alcohol, and from the 
 residue water extracts a small quantity of impure tan¬ 
 nin. The last method can be recommended only where 
 it is desired to obtain a pure acid without the trouble 
 of additional purification, for if made from Chinese 
 galls the product should be as pure as it is possible to 
 get the acid in one operation. It is not available as a 
 commercial process, on account of its expensiveness, 
 since the quantity of solvent recommended is insufficient 
 to completely extract the galls. 
 
 The above-mentioned processes have been enumer¬ 
 ated in order to criticise them, and at the same time 
 furnish information to those who wish to prepare tannic 
 acid from galls on a small scale. The following will 
 treat the subject from a commercial stand-point, and 
 describe what has been a process for producing the 
 tannic acid in quantity. 
 
 There are three varieties of the acid in commerce, 
 known as— 
 
 Ether-tannin (the German Schaum-Tannin), 
 Alcohol-tannin, 
 
 Water-tannin. 
 
 The first is the one best known in this country, although 
 one or both of the others may be had of importers and 
 manufacturers under the name of “ commercial tannin/’ 
 
 The Chinese or Japanese galls, on account of their 
 greater freedom from coloring-matter and larger per- 
 
82 
 
 THE TANNINS. 
 
 «centage of tannic acid, are by the manufacturer pre¬ 
 ferred to the Turkish variety. 
 
 The galls are first crushed and then passed through 
 a mill which will powder by cutting rather than by 
 grinding, so as to furnish a moderately fine powder 
 that is not “ balled” or “ caked.” 
 
 A quantity of the powder is then stirred, in a wooden 
 or copper vessel, with sufficient water to form a concen¬ 
 trated aqueous solution, or this may better be accom¬ 
 plished with a more complete exhaustion of the galls by 
 a battery of vessels or extractors in which the liquors 
 are run from one to another until of proper strength. 
 The temperature of the water is recommended to be 
 from 40° to 60°, although this varies with different 
 manufacturers. When the liquors have reached the 
 proper strength, they are run into a large settling-ves¬ 
 sel and allowed to cool and settle for twelve hours; 
 especially is this necessary if a higher temperature than 
 that above mentioned has been used. From the set¬ 
 tling-tub the liquor is run through a filter into a cylin¬ 
 drical copper vessel like a churn, in which are numerous 
 paddles so attached as to be capable of slow and contin¬ 
 uous revolution. To the liquor in this vessel about 
 one-fourth its volume of ether (specific gravity .750) 
 is added. The mixture is then thoroughly agitated by 
 means of paddles. The longer this operation is con¬ 
 tinued the better the product is supposed to be, and 
 when completed the emulsion-like liquid is run into a 
 settling-vessel and allowed to stand for from eight to 
 ten days, at the end of which time the complete separa¬ 
 tion into two layers will be found to have taken place. 
 
 The upper, ethereal layer, which holds in solution 
 
THE PREPARATION OF TANNIC ACID. 83 
 
 resin, fat, coloring-matter, gallic and ellagic acids, is 
 drawn off and the ether recovered by distillation. The 
 lower layer, consisting of water, ether, tannic acid, and 
 some impurities, is also run into a still and a portion 
 of the ether recovered by distillation until the liquid 
 reaches a syrupy consistence. After cooling, this liquid, 
 which still contains some ether, is spread by means of 
 a brush on plates of sheet tin, and the tin plates are 
 placed for a moment on the hot steam-coil, or flat iron 
 surface heated with steam, and over the whole is placed 
 a wooden box. The tannic acid almost immediately 
 “ puffs up” and dries, although this spongy condition 
 is said to be materially assisted by passing over the acid 
 a jet of dry steam, which softens it slightly and admits 
 of its swelling still further. Considerable practice and 
 dexterity are required in this operation, which exposes 
 the operator to the vapor of ether unless great precau¬ 
 tions are taken. Excellent results have also been gotten 
 by spreading the solution on plates of glass and placing 
 them in a drying-oven heated to 110°, which may be 
 so ventilated as to protect the operator. 
 
 The product is the ether-tannin, and should be nearly 
 white and completely soluble in water and in alcohol. 
 
 The needle or so-called “ crystal-tannin” is prepared 
 as above, but, instead of spreading the solution on tin 
 or glass, it is run through small holes and allowed to 
 fall in a very thin stream on a revolving hot cylinder 
 of copper, from which the dried product is scraped in 
 the needle form, which gives the impression of its being 
 crystallized. 
 
 Alcohol-tannin is prepared by extracting the galls 
 with diluted alcohol (50 per cent.) instead of water, care- 
 
84 
 
 THE TANNINS. 
 
 fully filtering, recovering as much of the alcohol as 
 possible, and completing the evaporation in a vacuum. 
 It is then broken into pieces which resemble rosin, and 
 sent into commerce in that form, or it is first powdered 
 by porcelain rollers, which operation gives it a much 
 lighter color. The product should be completely solu¬ 
 ble in water, indicating its freedom from resin. 
 
 Water-tannin is extracted similarly to the ether-tan¬ 
 nin, but after filtering, instead of mixing with ether, 
 the solution is run directly into a vacuum-pan and con¬ 
 centrated to dryness. It usually comes in commerce in 
 the powdered form, which operation is accomplished 
 similarly to the alcohol-tannin. 
 
 Purification .—Tannic acid prepared by the foregoing 
 methods is contaminated with fat, wax, resin, coloring- 
 matter, gallic acid, and glucose. For most purposes the 
 small amounts of these impurities are no objection, but 
 at times the chemist desires a product free from more 
 than traces of impurity, especially when the object is to 
 determine its ultimate composition. The fat, wax, some 
 coloring-matter, and the odorous principle may be re¬ 
 moved by percolation with petroleum ether. 
 
 A number of processes have been suggested for re¬ 
 moving the other impurities, all of which, however, 
 are attended with considerable waste. One method is 
 to take the best ether-tannin and treat it with stronger 
 ether, to which just sufficient water is added to effect 
 solution. This is best accomplished by using 100 
 grammes of the tannic acid, 150 cc. of stronger ether, 
 and 100 cc. of water. Three layers are formed, the 
 lowest of which is a concentrated solution of nearly 
 pure tannic acid. Considerable loss occurs by this pro- 
 
THE PREPARATION OF TANNIC ACID. 85 
 
 cess, as the middle layer contains some of the acid, 
 which, however, may be recovered by distilling the 
 ether and water under reduced pressure. The upper 
 layer consists of ether holding in solution resin, color¬ 
 ing-matter, and gallic acid. 
 
 Another method of purification consists in dissolving 
 the acid in water almost to saturation, and allowing to 
 stand to separate the resin and other, insoluble impuri¬ 
 ties. The clear liquid is removed by decantation, and 
 there is added to it a clear saturated solution of com¬ 
 mon salt, to this is added some solid sodium chloride in 
 order to completely precipitate the acid, which is col¬ 
 lected on a filter, dried carefully, and dissolved in a 
 mixture of alcohol and ether, or in acetic ether. Lowe 
 recommended to agitate the mixture after addition of 
 salt with acetic ether. In either case the solvent is 
 recovered by distillation, the residue dissolved in water 
 and agitated with ether, the latter separated, and the 
 aqueous solution distilled on a water-bath to dryness 
 under reduced pressure, which causes the acid to become 
 light colored and porous. Glucose is the most tenacious 
 impurity, resulting in part from the decomposition of 
 the tannic acid during each purification. 
 
 The following process, a combination of some previ¬ 
 ously-proposed methods, has been used by the author 
 with complete success, although, like other processes, 
 it is attended with considerable loss, which, however, 
 might in part be obviated if the quantity desired were 
 sufficient to warrant it. 
 
 Ten grammes of tannic acid are dissolved in 200 cc. 
 of water, and to the unfiltered solution a 10-per-cent, 
 solution of lead acetate is added drop by drop with con- 
 
 8 
 
86 
 
 THE TANNINS. 
 
 stant stirring until the precipitate ceases to be granular, 
 but is more milky in character, ceases to settle, and is 
 pure white in color, distinct from the yellowish color 
 caused by the first drops of the reagent. The filtrate 
 at this point will be colorless. It is important that the 
 solutions be as dilute as the above mentioned, or else 
 the precipitate of lead tannate will not carry down the 
 coloring-matter with it. After filtration the precipitate 
 is washed with sufficient water to bring 1 the filtrate to 
 the original volume. More washing than this is to be 
 avoided, on account of the tendency of the precipitate 
 to decompose. 
 
 The colorless filtrate, which contains free acetic acid, 
 is agitated with 75 cc. of pure acetic ether and the lat¬ 
 ter separated; this agitation is to be repeated twice 
 with the same volume of acetic ether; the three por¬ 
 tions are mixed and the ether recovered by distillation 
 under reduced pressure to dryness. A light, porous, 
 white tannic acid is obtained amounting to 41 per cent, 
 of the original quantity. It contains gallic acid and 
 has a pungent acetous odor; the aqueous solution of a 
 portion of it, after the removal of the tannic acid by 
 lead oxyacetate, gives no reaction with Fehling’s solu¬ 
 tion for glucose. The tannic acid is further purified by 
 dissolving in water, agitating the solution with stronger 
 ether to remove gallic acid, and distilling the aqueous 
 solution to dryness under reduced pressure. This is 
 once more dissolved in ether with a little water, and 
 again brought rapidly to dryness under reduced press¬ 
 ure. The result is a pure white product which gives 
 no reactions for gallic acid or glucose. A sample pre- 
 
THE PREPARATION OF TANNIC ACID. 87 
 
 pared by these directions when dried at 120° gave the 
 following percentage composition : 
 
 52.10 per cent. 
 
 C . 
 H . 
 O . 
 
 3.52 “ 
 
 44.38 “ 
 
 100.00 “ 
 
 An acetyl derivative was prepared of the same 
 sample which melted at 139°, and by boiling with 
 magnesium oxide according to the usual process gave 
 very close to the theoretical quantity of magnesium 
 pyrophosphate that would indicate pentacetyl-tannin. 
 
SECTION IV. 
 
 THE PROPERTIES OF TANNIC ACID. 
 
 Tannic acid occurs in yellowish-white amorphous 
 powder or masses which are easily pulverized; it is 
 odorless, and possesses a strongly astringent taste, free 
 from bitterness. By exposure to light it becomes yel¬ 
 low to brown in color. 
 
 It is soluble in 6 parts of water, in 6 parts of glycerin, 
 and in 0.6 part of alcohol. The solutions are yellow 
 in color, react acid with litmus, and are nearly without 
 action on polarized light. Ether containing water or 
 alcohol dissolves tannic acid, but absolute ether dis¬ 
 solves it sparingly, while it is insoluble in chloroform, 
 benzol, petroleum ether, carbon disulphide, fixed and 
 volatile oils, except oil of bitter almond, which dis¬ 
 solves it. 
 
 A number of salts, as potassium acetate, ammonium 
 chloride, calcium chloride, and sodium chloride, as well 
 as the mineral acids, sulphuric, hydrochloric, arsenic, 
 and boric acids, precipitate tannic acid from its concen¬ 
 trated aqueous solution. Nitric acid does not so pre¬ 
 cipitate it. When air and light are excluded from the 
 aqueous solution of tannic acid, it remains for some 
 time without decomposition, but in contact with air 
 oxygen is absorbed, with the formation of a dark color 
 and the production of sugar, gallic acid, and sometimes 
 88 
 
THE PROPERTIES OF TANNIC ACID. 89 
 
 ellagic acid; by prolonging this action carbon dioxide 
 aud oxalic acid also result. 
 
 When subjected to heat tannic acid changes but little 
 until 120° is reached, when it assumes a grayish color, 
 without, however, undergoing apparent decomposition, 
 at 140° it is darker, and at from 160° to 215° there 
 are formed carbon dioxide, pyrogallic acid, water, and 
 metagallic acid. The last is not volatile, while the 
 others are volatile; and this admits of a ready method 
 of separating the meta-acid, which remains behind as 
 a-black, amorphous mass, from the pyro-acid, which 
 sublimes in acicular crystals. Since the latter vola¬ 
 tilizes at 210°, it is natural to suppose that, in order to 
 obtain it from tannic acid, its volatilizing temperature 
 must be reached; but it is found that the decomposi¬ 
 tion begins at 160°, and, in the escape of carbon dioxide 
 and water, pyrogallic acid is carried off and condensed 
 in the cooler parts of the vessel. The best yield is ob¬ 
 tained by allowing the temperature to rise very slowly 
 to 215°, keeping it between 190° and 210° for one- 
 half hour. If the heat be increased rapidly to 215°, 
 there will be a small quantity of the pyro-acid and a 
 larger amount of the meta-acid produced. 
 
 On heating with a 2-per-cent, solution of absolute 
 hydrochloric acid, tannic acid is converted into gallic 
 acid: 
 
 QuHxoOg -f- H 2 0 = 2C 7 H 6 0 5 . 
 
 The pure acid yields gallic acid only, but that usually 
 met with gives variable amounts of glucose and ellagic 
 acid at the same time. 
 
 With solutions of the alkalies gallic acid is formed, 
 8 * 
 
90 
 
 THE TANNINS . 
 
 together with a dark color due in part to metagallic 
 acid and in part, when commercial acid is used, to the 
 action of the alkali on the glucose present. 
 
 Ammonia acts differently from the fixed alkalies. 
 When tannic acid is heated with aqueous ammonia in 
 an atmosphere free from oxygen, which is best ac¬ 
 complished by passing hydrogen into the mixture, there 
 are formed gallamide and ammonium gallate, according 
 to the following equation : 
 
 c 14 h 10 o 9 + 2NH 3 =c 7 h 5 o 4 nh 2 + nh 4 c 7 h 5 o 5 - 
 
 Fermentation causes the change of tannic into gallic 
 acid, several decomposition products resulting at the 
 same time. 
 
 Ferric salts produce a blue-black color or precipitate 
 with tannic acid, according to the concentration of the 
 solutions. When the solution of iron salt is very di¬ 
 lute, or when free acid, especially tartaric, is present, 
 the color is greenish. 
 
 Ferrous salts, when perfectly pure, added to tannic 
 acid solution produce no change unless the solutions be 
 concentrated, when a white gelatinous precipitate forms. 
 The least trace of ferric salt is sufficient to change this 
 to a dark-blue color or precipitate, according to the 
 strength of the solution. Soluble vanadium salts also 
 produce the blue-black color or precipitate with tannic 
 acid. 
 
 Tannic acid precipitates most alkaloids and bitter 
 principles. It gives a light-colored flocculent precipi¬ 
 tate with gelatin, which is rendered more insoluble by 
 alum, ammonium chloride, or sodium chloride; solu¬ 
 tions of starch and albumen are similarly precipitated. 
 
THE PROPERTIES OF TANNIC ACID. 91 
 
 Most metallic salts form precipitates with tannic 
 acid : tin salts produce a light-colored precipitate; lead 
 salts, a white precipitate, which darkens on exposure to 
 air; copper salts give a dark-brown precipitate; and 
 silver salts, brown precipitates. Tartar emetic causes 
 no precipitate until ammonium chloride is added. 
 Manganese acetate causes a white precipitate; uranium 
 acetate, a crimson or dark-red color, changing to a brown 
 precipitate; potassium dichromate gives a brown pre¬ 
 cipitate; lime-water causes a white precipitate, turning 
 blue. 
 
 According to Berzelius, when boric acid is dissolved 
 in a hot solution of tannic acid, there is formed a white 
 jelly on cooling, which may be dried to a white powder. 
 Tannic acid displaces carbon dioxide from carbonates 
 and forms tannates; those of the alkalies rapidly turn 
 dark when exposed to the air. Fehling’s solution is 
 reduced by tannic acid, with formation of cuprous ox¬ 
 ide ; in order, therefore, to determine the presence of 
 glucose the acid must first be removed by lead acetate. 
 A. H. Allen gives the following characteristic test for 
 tannic acid : a dilute ammoniaeal solution of potassium 
 ferricyanide, which causes a deep-red color changing to 
 brown. The reaction is very delicate, and the coloi 
 is destroyed by an excess of the reagent. A similar 
 reaction is caused by gallic acid. 
 
 Ammonium molybdate gives with tannic acid a rod- 
 dish-yellow color, which is destroyed by oxalic acid. 
 A solution of iodine in potassium iodide, when mixed 
 with a small quantity of ammonia which has been pre¬ 
 viously diluted with ten times its volume of water, 
 produces with'tannic acid a brilliant red color. 
 
92 
 
 THE TANNINS. 
 
 Tannates are formed by addition of the acid to car¬ 
 bonates or hydrates in the case of the alkalies, and to 
 hydrates in the case of the alkaline earths. With the 
 metals it forms tannates on its addition to an acetate. 
 By certain precautions the purity of the salt may be 
 improved,—for instance, by the use of alcoholic solu¬ 
 tions in the preparation of the alkali salts. Sodium 
 tanuate, JNaC 14 H 9 0 9 , and potassium tannate, KC 14 H 9 0 9 , 
 are obtained as crystalline precipitates by adding an al¬ 
 coholic solution of the hydrate to an alcoholic solution 
 of tannic acid ; the precipitate dries to a fine powder. 
 
 Barium tannate, Ba(C 14 H 9 0 9 ) 2 , is formed by pre¬ 
 cipitating the sodium salt with barium chloride. An¬ 
 other barium salt, of the formula Ba(OH)C 14 H 9 0 9 , is 
 formed by adding barium carbonate to a hot aqueous 
 solution of tannic acid. 
 
 At least three lead salts are known. According to 
 Pelouze and Strecker, the compound 3PbC 14 H 8 0 9 -f 
 Pb(C 14 H 9 0 9 ) 2 + 2H 2 0 is formed by precipitating lead 
 acetate with an excess of tannic acid. Strecker is also 
 authority for the compound 2PbC 14 H 8 0 9 + Pb(OH) 2 
 by precipitating tannic acid with an excess of lead 
 acetate, and the compound Pb 3 (C 14 H 7 0 9 ) 2 -f 2Pb(OH) 2 
 by heating an excess of lead acetate with a dilute tannic 
 acid solution. Scliiff found two salts according as the 
 tannic acid or lead acetate is in excess, an excess of the 
 acid giving Pb 2 C 14 H 6 0 9 + 2H 2 0 and an excess of the 
 lead salt giving Pb 3 C 14 IP 4 0 9 . The compounds with 
 lead have probably been studied more than any of the 
 other tannates, and many besides those given above 
 have been described. 
 
 The tannates of iron have also received a large share 
 
THE PROPERTIES OF TANNIC ACID. 
 
 93 
 
 of attention. The compounds Fe(C u H 8 0 9 )(C 14 H 9 0 9 ) 
 and Fe(C u H 9 0 9 ) 3 + Fe0(C 14 H 9 0 9 ) have been described. 
 All the tannates of iron are unstable, and we know 
 them best in solution as ink. A compound of tannic 
 acid with aluminium has been prepared by adding alu¬ 
 minium hydrate to tannic acid solution ; the compound 
 is soluble in excess of the acid. Zinc tannate is formed 
 bv precipitating an alkali tannate with zinc sulphate, 
 or by adding the acid to ammoniacal zinc sulphate. 
 Copper tannate, Cu 3 C u H 4 0 9 , is formed by precipitating 
 the acid with copper acetate. When alkali is added 
 the precipitate redissolves, and reduction to cuprous 
 oxide takes place. Wackenroder is authority for the 
 statement that, when the copper tannate which has 
 been prepared by an excess of the acid is dissolved in 
 ammonium hydrate, the copper is not precipitated 
 therefrom on the addition of hydrogen sulphide. 
 
 Compounds of tannic acid with nearly every known 
 metal are described in many of the text-books, but 
 many of these salts were made by the older chemists 
 before the acid had been prepared pure; consequently, 
 beyond the fact that we get insoluble compounds of a 
 certain color, there is very little accurate knowledge 
 concerning them. 
 
SECTION v. 
 
 THE COMPOSITION AND CONSTITUTION OF TANNIC 
 ACID. 
 
 As stated in the history, numerous investigators in 
 the first half of this century made efforts to establish 
 the composition of tannic acid. Mulder actually de¬ 
 termined the formula, C 14 H 10 O 9 , accepted at the present 
 time. It was not, however, until Lowe in 1867 pre¬ 
 pared digallic acid by treating barium gallate with sil¬ 
 ver nitrate, and Schiff in 1871 studied the conversion 
 of gallic into tannic acid by means of phosphorus 
 oxychloride, that the foundation of our present knowl¬ 
 edge was laid. 
 
 No better idea can be given of the importance of 
 Schiff’s work than by quoting portions of his papers. 
 He first called attention to the fact that some chemists 
 held the view that tannic acid was a glucoside, while 
 others considered glucose to be an admixture, which 
 varied much in its proportion, and that the behavior of 
 the acid towards reagents was not altered by the removal 
 of the glucose. SchifFs method of forming digallic 
 acid was as follows : 
 
 “When well-purified gallic acid dried at 110° is 
 mixed with phosphorus oxychloride to the consistence 
 of an emulsion and heated in a water-bath at 100° and 
 afterwards in an oil-bath to 120°, there follows an abun- 
 
 94 
 
COMPOSITION OF TANNIC ACID. 
 
 95 
 
 dant evolution of hydrochloric acid. The gallic acid 
 is converted into a yellow powder, which is washed by 
 decantation with several portions of absolute ether. 
 
 “ The ether is removed from the residue by gentle 
 warming and then dissolved in a small quantity of 
 water. After twelve hours’ standing the gallic acid 
 crystallizes out and is removed, and to the yellowish- 
 red solution is added sufficient common salt to saturate 
 it, causing a separation of the resin-like mass, which is 
 easily separated from the liquid and washed twice with 
 saturated salt solution. 
 
 “ The resin-like mass is dried under reduced press¬ 
 ure, dissolved in a small quantity of absolute alcohol, 
 to remove salt, and to the clear alcoholic solution is 
 added an equal volume of ether, filtered, the solvent 
 distilled off, and the amorphous residue dried in a 
 vacuum. 
 
 “The varnish-like, nearly colorless residue gives 
 similar reactions, solubility, physical properties, taste, 
 etc., which are considered characteristic of tannic acid. 
 
 “ It is the first absolutely sugar-free tannic acid.” 
 
 The amorphous residue was entirely reconverted into 
 gallic acid on boiling with hydrochloric acid, and this 
 gallic acid again converted into the amorphous acid by 
 the phosphorus oxychloride. 
 
 Two elementary analyses gave the following: 
 
 i. n. 
 
 C. 51.7 52.3 
 
 H. 3.8 4.1 
 
 The question in regard to the nature of tannic acid 
 was answered as follows : 
 
96 
 
 THE TANNINS. 
 
 “ Tannic, acid is an alcoholic anhydride of gallic acid, 
 
 very probably digallic acid.” 
 
 This structural formula was at first suggested by 
 
 Schiff: 
 
 Tannic Acid. 
 
 Gallic Acid. 
 
 He subsequently changed this formula to that of an 
 ethereal anhydride, as follows : 
 
 OH 
 
 OH 
 
 OH 
 
 CO\ 
 
 O / 
 
 OH 
 
 OH 
 
 CO.OH 
 
 Schiff* also investigated the reaction, first described 
 by Lowe, of arsenic acid and gallic acid, which the 
 latter considered to be an oxidation. Schilf, however, 
 obtained similar results as with phosphorus oxychlo¬ 
 ride, and considered it an easier method for obtaining 
 digallic acid, since heating the gallic acid with a dilute 
 solution of arsenic acid was sufficient to effect the con¬ 
 version. There is, however, considerable difficulty in 
 removing the arsenic from the tannic acid, a portion of 
 the latter being reconverted into gallic acid. 
 
COMPOSITION OF TANNIC ACID. 
 
 97 
 
 By heating cligallic acid as well as a purified natu¬ 
 ral tannic acid with acetic anhydride, Schiff obtained 
 pentacetyl-tannin, C 14 H 5 (C 2 H 3 0) 5 0 9 , consisting of warty 
 crystals melting at 137°. This compound is insoluble 
 in water and cold alcohol, but moderately soluble in 
 hot absolute alcohol, and gives no color reaction with 
 salts of iron. 
 
 Two years later, in 1873, Schiff published a review 
 of his former work, with the maturer conclusions which 
 experience gave him. He offered the following as the 
 reaction taking place between gallic acid and phos¬ 
 phorus oxychloride : 
 
 . 4C 7 H 6 O s + POCl 3 = 2C 14 H 10 O 9 + PH0 3 + 3HC1. 
 
 The tannic acid thus obtained gave a blue-black precip¬ 
 itate with ferric salts, yielded pyrogallic acid on heat¬ 
 ing, and was converted into gallic acid by the action of 
 dilute acids, without the formation of a trace of glucose. 
 Phosphorus pentachloride and trichloride also con¬ 
 verted gallic into tannic acid, but some intermediate 
 and decomposition products resulted. 
 
 Schiff also further investigated the action of arsenic 
 acid on gallic acid, and determined that when they are 
 heated together in aqueous solution the change into 
 tannic acid is complete without the arsenic acid under¬ 
 going any change. He considered the reaction to be as 
 follows: 
 
 (1) C 7 H 5 0 4 -OH + HAsO s = C 7 H 5 0 4 -0. As0 2 + h 2 o ; 
 
 (2) C? A A} 0 +°>ha.oh =%1$} o+ asho 3 . 
 
 Pure digallic acid was recommended to be prepared 
 9 * 
 
98 
 
 THE TANNINS. 
 
 by boiling an alcoholic solution of gallic acid and ar¬ 
 senic acid, the arsenic to be removed from the filtrate by 
 hydrogen sulphide, the solution evaporated to dryness, 
 dissolved in a small quantity of alcohol, ether added in 
 excess, filtered, and the filtrate evaporated to dryness. 
 
 In a former paper Sell iff supposed he had prepared a 
 triacetyl and a tetraacetyl derivative of tannic acid, but 
 later investigation convinced him that only the pentace- 
 tyl tannin existed, the other compounds being mixtures 
 which resulted from the digallic acid containing some 
 intermediate products with phosphorus. 
 
 Schiff at first concluded that “ the compound present 
 in the plants which yield tannic acid is probably a very 
 unstable glucoside of polygallic acid, perhaps of the 
 formula indicated by Strecker.” “The least purified 
 tannic acid is then the purest, since it contains the 
 largest proportion of sugar.” 
 
 Later he made the following statement: “ That the 
 glucose present in imperfectly purified natural tannin 
 does not exist in the free state is proved by the fact that 
 ether-alcohol and anhydrous alcohol dissolve such tan¬ 
 nin freely. Unaltered tannin is probably a glucoside 
 of digallic acid 
 
 QnH 28 0 22 = C 6 H 12 0 6 + 2C 14 H 10 O 9 - 2H 2 0. 
 
 This formula corresponds with 23 per cent, glucose, 
 and the amount of this substance obtained from natural 
 tannin varies from nothing to 22 per cent., according to 
 the extent to which the tannin has been subjected to 
 purification. 
 
 C. Etti in 1884 coincided with SchitFs view of the 
 constitution of tannic acid. 
 
COMPOSITION OF TANNIC ACID. 
 
 99 
 
 We must conclude, from our present knowledge, that 
 the tannin from galls as found in commerce is capable 
 of being purified until it is simply digallic acid. It is, 
 however, rarely, if ever, found in this condition, but 
 contains variable amounts of glucose in weak combina¬ 
 tion ; therefore tannic acid as we know it is either a 
 glucoside of digallic acid or a mixture of this glucoside 
 with variable proportions of digallic acid. 
 
INDEX OF AUTHORS, 
 
 A. 
 
 Adrian, 159. 
 
 Aikin, A., 119. 
 
 Allen, A. H., 140. 
 Angillis-Mortier, 126. 
 Arata, P. N., 144, 149. 
 Archer, 135. 
 Arnaudon, J. S., 144. 
 Arnaudon, S. S., 159. 
 
 B. 
 
 B. E., 155. 
 
 Baehr, R., 136. 
 Barhieri, 143. 
 
 Barfoed, C., 136. 
 Barreswil, 122. 
 Barrow, J., 138. 
 Bartholdi, 111. 
 Bassermann, F., 118. 
 Bastow, E., 156. 
 Baup, S., 117. 
 
 Becker, F., 153. 
 
 Bell, J., 121, 126. 
 Benoist, L., 157. 
 Bense, F. A. W., 154. 
 Beral, 120. 
 
 Berthellot, A. B., 112. 
 Berthellot, C. L., 112. 
 Bertrand, 126. 
 Berzelius, J. J., 116. 
 Bevan, E. J., 150. 
 Biggin, G., 110. 
 
 Bihot, L., 131. 
 
 Bissell, E. G., 144. 
 
 Bissell, W. B., 154. 
 
 Bley, L. F., 126, 128. 
 
 Bolley, P., 131, 133, 136. 
 Bottinger, C., 148,150,152,153, 
 156, 157,158,159,160,162. 
 Bouillon-Lagrange, 111. 
 Bowman, H. K., 138. 
 Braconnot, H., 114, 118, 125. 
 Braemer, L., 159. 
 
 Brande, W. T., 114. 
 
 Braun, C. D., 137. 
 
 Breutel, E., 155. 
 
 Bridges, R., 122. 
 
 Brugnatelli, L. V., 113. 
 Buchner, A. W., 118, 126. 
 Buchner, L. A., 126. 
 
 Buchner, Ph., 123, 136. 
 
 Bujard, A., 162. 
 
 Burridge, J., 116. 
 
 Biisgen, 160. 
 
 C. 
 
 Cadet, 114. 
 
 Calvert, C., 129, 139. 
 
 Cap, 131. 
 
 Carles, P., 152. 
 
 Carpene, 142. 
 
 Casali, A., 152. 
 
 Casthelaz, 154. 
 
 Cavarra, A., 120. 
 
 Cavillius, 122. 
 
 Cech, C. O., 136. 
 
 Chaptal, B., 110. 
 
 Chevreul, 114. 
 
 103 
 
104 
 
 THE TANNINS. 
 
 Christy, T., 144, 149. 
 
 Clark, 143. 
 
 Colin, 157. 
 
 Collier, P., 146, 147, 148. 
 Commaile, 133. 
 
 Cooper, J. T., 123. 
 
 Councler, C., 150, 151, 158. 
 Credner, H., 121. 
 
 Creuzburg, H., 119. 
 
 Cross, C. P., 150. 
 
 Cusson, 160. 
 
 D. 
 
 D., Dr., 153. 
 
 Darton, N. H., 149. 
 
 Davies, E., 148. 
 
 Davies, J. W., 132. 
 
 Davy, H., 112. 
 
 Delachanal, 156. 
 
 Descostiles, 110. 
 
 Desmond, W., 110. 
 
 Deyeux, C., 109. 
 
 Dierbach, 118. 
 
 Dieudonne, H., 155. 
 
 Dize, J. J., 109. 
 
 Domine, 123. 
 
 Dorffurt, 112. 
 
 Doubleday, E., 125. 
 
 Doutreleau, J., 153. 
 
 Dowling, J., 131. 
 
 Dreykorn, 138. 
 
 D’Urban, 132. 
 
 Durien, E., 154. 
 
 Duval, 121. 
 
 Dvorkovitch, P., 162. 
 
 E. 
 
 Eder, J. M., 145, 146, 147. 
 Eitner, W., 147, 150, 151, 155, 
 161, 162. 
 
 Erbstein, K. E. W., 110. 
 Erdmann, O. L., 117. 
 
 Estcourt, C., 141, 145. 
 
 Etti, C., 143, 148, 149, 151, 152, 
 158. 
 
 F. 
 
 Facilides, O., 137. 
 
 Fay, A., 110. 
 
 Fehling, 128. 
 
 Fernandez, 113. 
 
 Fleck, H., 131. 
 
 Fdlsing, A., 161. 
 
 Freda, P., 145, 146, 147. 
 Frerichs, 125. 
 
 Fridolin, A., 151. 
 
 Fuchs, 110. 
 
 G. 
 
 Gantter, F., 159. 
 
 Gardiner, W-, 152. 
 Gartenmeister, 160. 
 
 Gaube, F., 133. 
 
 Gautier, A., 143, 144, 145. 
 Gawalovski, A., 150. 
 
 Geiseler, 130. 
 
 Geisler, J. F., 152. 
 
 Gerland, B. W., 133. 
 
 Giles, J., 117. 
 
 Gintl, W., 150. 
 
 Girardin, 121. 
 
 Giraud, 160. 
 
 Girgensohn, L., 141. 
 
 Godeffroy, 147. 
 
 Gondolo, P., 149. 
 
 Good, W., 115. 
 
 Grabowski, A., 134, 135, 137. 
 Graham, T., 132. 
 
 Grassi, E., 140, 142. 
 Grassmann, 114. 
 
 Gray, G., 110. 
 
 Green, F. V., 144. 
 
INDEX OF AUTHORS. 
 
 105 
 
 Griessmayer, V., 139. 
 
 Guenez, E., 160. 
 
 Guibourt, 122, 124, 125. 
 Guignet, 0. E., 162. 
 
 Guillot, M., 111. 
 
 Giintber, N., 138. 
 
 Guyard, A., 152. 
 
 H. 
 
 Haddock, A. G., 147. 
 
 Hagen, 121. 
 
 Hallwachs, 133. 
 
 Hamilton, W., 124. 
 
 Hammer, K., 131. 
 
 Handtke, R., 132. 
 
 Harff, H., 119. 
 
 Hartig, T., 137. 
 
 Hartwich, 0., 147,148, 151,162. 
 Hatchett, C., 113. 
 
 Hatzfeld, A., 141. 
 
 Heinecke, 128. 
 
 Heinz, H. J., 134, 139. 
 
 Hennig, C., 128. 
 
 Henry, M., 116, 154. 
 
 Henry, 0., 118. 
 
 Hermbstadt, S. E., 111. 
 
 Hesse, O., 157. 
 
 Heumann, C., 122. 
 
 Hill, A., 149. 
 
 Hinsdale, S. J., 160. 
 
 Hlasiwetz, H., 135, 136, 137. 
 Hohnel, E. R., 148. 
 
 Hooper, D., 159. 
 
 Hooxman, P. J., 143. 
 
 Hornung, 123. 
 
 Hoi’sley, J., 129. 
 
 Howison, J., 112. 
 
 Hunefeld, 121. 
 
 Hunt, B., 154. 
 
 Hurst, G. H., 155. 
 
 I. 
 
 Ishikawa, I., 148. 
 
 J- 
 
 Jackson, R., 152. 
 
 Jahn, H., 146. 
 
 Jahoda, R., 161. 
 
 Jean, E., 143,144, 150, 154,162. 
 Jennings, H. C., 130. 
 
 •Tohanson, E., 143,145, 149, 151. 
 John, 114. 
 
 Johnson, A., 111. 
 
 Jorissen, A., 150. 
 
 Judd, W., 133. 
 
 K. 
 
 Kaemmerer, H., 143. 
 Kalinowsky, J., 123. 
 Kampffmever, 123, 124. 
 
 Kapff, S., 161. 
 
 Karsten, E. J. B., 111. 
 
 Kastner, K. W. G., 123. 
 Kathreiner, F., 145, 146, 147. 
 Kawalier, 129, 130. 
 
 Kay, P. 156. 
 
 Kendrick, W., 115. 
 
 Kestler, C., 117. 
 
 Kingzett, C. T., 146. 
 
 Klinger, A., 162. 
 
 Knop, A., 127. 
 
 Knop, W., 127. 
 
 Koch, R., 157, 158. 
 
 Koechlin, J., 150. 
 
 Kohlrausch, O., 149. 
 
 Kohnstein, B., 153. 
 
 Kopp, E., 133. 
 
 Kraus, G., 159. 
 
 Kubly, 135. 
 
 Kursak, 132. 
 
106 
 
 THE TANNINS. 
 
 Kurtz, C. M., 140. 
 
 Kutscher, F., 159. 
 
 L. 
 
 Lacaze-Duthiers, 128. 
 
 Lamasse, 152. 
 
 Lambert, A., 159. 
 
 Lang, C., 128. 
 
 Larocque, A., 121. 
 
 Laurent, A., 127. 
 
 Leconnet, 119. 
 
 Leeds, A. It., 148. 
 
 Lehman, A., 148, 150. 
 
 Lelievre, 110. 
 
 Leuchs, J. C., 132. 
 
 Lidow, A., 158. 
 
 Liebig, J., 117, 118, 120. 
 Lotichius, C. A., 140. 
 
 Lowe, J., 135,137, 139,140,141, 
 142, 148. 
 
 LOwenthal, J., 131, 144. 
 
 Ldwig, C., 120. 
 
 Luboldt, 130. 
 
 Luca, S. D., 149. 
 
 Luck, E., 126, 
 
 Luckombe, 125. 
 
 M. 
 
 Mabern, T., 153. 
 
 Macadam, 117. 
 
 Macagno, J., 140, 148, 156. 
 Macbride, D., 109. 
 
 Macewan, P., 153. 
 
 Maiden, J. H., 160. 
 
 Malin, G., 135. 
 
 Maltchewsky, 160. 
 
 Marquart, L. C., 118. 
 Marriage, J. H., 132. 
 
 Martius, T. W. C., 120. 
 Masson, 146. 
 
 Maumene, 142. 
 
 McMurtrie, W., 139, 143, 144. 
 Meerkatz, J., 155, 158. 
 Mercadante, 141. 
 
 Merrick, J. M., 140. 
 
 Meyer, G-., 160. 
 
 Mierzinski, S., 156. 
 
 Minutoli, 116. 
 
 Mittenzwey, 133. 
 
 Moeller, J., 145, 147. 
 
 Mohr, 124. 
 
 Moll, J. W., 153, 155. 
 
 Monier, 130. 
 
 Moullade, A., 160. 
 
 Mulder, G. J., 125. 
 
 Muller, F., 122. 
 
 Muller, G., 131. 
 
 Muller, J., 125. 
 
 Mulligan, J., 131. 
 
 Miintz, A., 138, 141, 142, 143, 
 149. 
 
 Musset, F., 151, 153. 
 
 N. 
 
 Nass, P., 152. 
 
 Nasse, O., 152. 
 
 Nees v. Esenbeck, 116, 117. 
 Neubauer, C.. 129, 139, 140. 
 Neubrand, J. G., 138. 
 
 Notzli, 155. 
 
 O. 
 
 Orth, V., 129. 
 
 Oser, J., 143. 
 
 P. 
 
 Palm, R., 139. 
 
 Palmer, A. W., 145. 
 
 Palmer, T. C., 156. 
 
 Parrish, E., 131. 
 
INDEX OF AUTHORS. 
 
 107 
 
 Passler, J., 161. 
 
 Patterson, W., 120. 
 
 Paul, B. H., 130, 146. 
 
 Pavesi, 141. 
 
 Payen, 119. 
 
 Peacock, J. C., 162. 
 
 Peligot, E., 122. 
 
 Pelletier, 110, 114. 
 
 Pelouze, «T., 118. 
 
 Pereira, J., 123. 
 
 Perret, E., 145, 152. 
 Pettenkofer, 128. 
 
 Pfaff, C. H., 113, 114, 117. 
 Plisson, 116. 
 
 Pohl, J. J., 129. 
 
 Preisser, F., 121. 
 
 Pribram, B., 134. 
 
 Procter, H. K., 141, 143, 144, 
 145,155,156,160,161,162. 
 Procter, W., 133. 
 
 Proctor, B. S., 158. 
 
 Proust, 110, 111. 
 
 Prud’homme, 140. 
 
 R. 
 
 Raabe, 148. 
 
 Ramspaclier, 141, 142. 
 
 Ranke, EL, 127. 
 
 Rau, H. M., 156. 
 
 Rawson, S. G-., 159. 
 
 Rebling, 129. 
 
 Regnauld, J., 141. 
 
 Reich ardt, 138. 
 
 Reinitzer, E., 150, 158. 
 
 Reinsch, 120, 135. 
 
 Rembold, O., 134, 135, 137. 
 Remont, A., 149. 
 
 Richards, E. S., 145. 
 
 Riche, 149. 
 
 Riegel, 151. 
 
 Risler-Beunat, 133. 
 
 Robiquet, 119, 120. 
 
 Robiquet, E., 127, 128. 
 Rochleder, F., 124, 125, 127, 
 128, 129, 130, 134, 135,136, 
 137. 
 
 Roder, 126. 
 
 Rodsey, 117. 
 
 Roos, L., 160. 
 
 Roques, 151. 
 
 Rothe, O., 138. 
 
 Rotondi, 141. 
 
 Roxburgh, W., 112. 
 
 Rulf, 153. 
 
 Rutsch, 125. 
 
 S. 
 
 Sacc, 138. 
 
 Salzer, Th., 137. 
 
 Sandrock, B., 127. 
 
 Saul, J. E., 155. 
 
 Schel, J., 142. 
 
 Schenk,126. 
 
 Scherer, J. A., 112. 
 
 Scherk, C., 162. 
 
 Schiff, H., 130, 139, 140, 142, 
 146, 147, 156. 
 Schlumberger, A., 132. 
 
 Schmidt, 141. 
 
 Schmieden, T., 137. 
 
 Schoen, 149. 
 
 Schonbein, C. F., 131. 
 
 Schroder, J., 150, 157, 161. 
 Schubarth, 123. 
 
 Schulze, E., 158. 
 
 Schulze, F., 134. 
 
 Schwarz, R., 128. 
 
 Seemann, 126. 
 
 Seguin, A., 110. 
 
 Sertiirner, F., 113. 
 
108 
 
 THE TANNINS. 
 
 Sharpies, S. P., 151. 
 
 Sheldon, W., 115. 
 
 Siedler, P., 161. 
 
 Siewart, 136, 145. 
 
 Simand, 150, 151,153, 155,156, 
 157. 
 
 Simpkin, S. J., 142. 
 
 Skey, W., 134. 
 
 Smedt, 133. 
 
 Sonne, W., 159. 
 
 Sonnenschein, 153. 
 
 Sprengel, C , 117. 
 
 Staffel, 126. 
 
 Stein, W., 125. 
 
 Stenliouse, J., 121,122,123,132, 
 141, 142. 
 
 Stocder, 143. 
 
 Strecker, A., 127, 128. 
 Svanberg, 119. 
 
 Swayne, 109. 
 
 T. 
 
 Terreil, A., 140. 
 
 Thompson, W-, 142. 
 
 Tieghman, Ph., 134. 
 
 Tod, W., 129. 
 
 Tollens, 158. 
 
 Tonner, 132. 
 
 Toulmouche, 119. 
 
 Trimble, 156, 157, 158, 160, 162. 
 Tromer, 110. 
 
 Trommsdorff, J. B., 112, 118. 
 Turnbull, 124. 
 
 U. 
 
 Ulbricht, E., 154. 
 
 V. 
 
 Yauquelin, 111. 
 
 Yedova, F. G., 146. 
 
 Vignon, L., 160. 
 
 Villon, A., 156, 159. 
 
 Vincent, 156. 
 
 Vinen, 129. 
 
 Virey, D’A., 115. 
 
 Virey, J. J., 115, 116. 
 
 Vogel, J. IE, 161. 
 
 W. 
 
 Waage, Th., 161. 
 
 Wackenroder, H., 120, 121. 
 Wagner, E., 158. 
 
 Wagner, R., 126, 127, 134, 139. 
 Waltl, J., 116. 
 
 Warington, R., 124. 
 
 Watson, W., 146. 
 
 Watts, J., 135. 
 
 Wehmer, 158. 
 
 Weiss, B., 155. 
 
 Westermaier, 153. 
 
 Wetherill, O., 124. 
 
 White, J. T., 159. 
 
 White, T., 114. 
 
 Whitely, R. L., 161. 
 
 Wiegand, 132. 
 
 Wildenstein, R., 133. 
 Willuszewitcz, 155. 
 
 Wittstein, G. C., 127. 
 
 Wohler, 125. 
 
 Wohmann, W., 140. 
 
 Wolf, A., 138. 
 
 Wolff, E., 132. 
 
 Wood, J. T., 161. 
 Wosresensky, A., 120. 
 
 Wuttig, J. F. C., 113. 
 
 Z. 
 
 Ziegler, E., 154, 156. 
 
 Zolffel, G., 161. 
 
 Zwenger, C., 121. 
 
INDEX 
 
 TO THE 
 
 LITERATURE OF THE TANNINS. 
 
 1791. 
 
 Abgekurztes Yerfahren, die Gallapfelsaure zu gewin- 
 nen. Yon Mich. Jean Jerome Dize. Jour. Physik, 7 , 
 399 (abstract 1793) ; from Observations sur la phy¬ 
 sique, sur l’histoire naturelle et sur les arts, par MM. 
 l’Abbe Rozier, Mongez et JDe la Metherie, 39 , 420, 
 Paris, 1791. 
 
 1792. 
 
 Communication relative to the use of Oak-Leaves in 
 Tanning. By George Swayne. Trans. Soc. Arts, 10 ,153. 
 
 1793. 
 
 Memoire sur la noix de galle, nontenant son analyse, 
 celle de l’acide gallique, et un examen particular du 
 precipite opere par ses deux substances lorsqu’on les 
 mele avec le sulfate de fer. Par le cit. Deyeux. Ann. 
 Chim,, 17 , 1; abstract Jour. Physik, 42 , 401. 
 
 1795. 
 
 An Improved Method of Tanning Leather. By 
 David Macbride, M.D. Repert. Arts and Manuf., 2 , 
 341 and 382. 
 
 10 
 
 109 
 
110 
 
 THE TANNINS. 
 
 1796 . 
 
 Some considerable Improvements in the Art of Tan¬ 
 ning Leather. Patent to Anthony Fay, dated July 17, 
 1790. Repert. Arts and Manuf., 4 , 217. 
 
 Rapport au Comite de Salut public, sur les nouveaux 
 moyens de tanner les cuirs, proposes par le cit. Armand 
 Seguin. Par les citoyens Lelievre et Pelletier. Ann. 
 Chim., 20 , 15. Translation in Repert. Arts and Manuf., 
 8 , 272 and 341. 
 
 1797 . 
 
 Method or Process of Tanning all Sorts of Hides and 
 Skins, &c. Patent to William Desmond, dated January 
 15, 1796. Repert. Arts and Manuf., 6 , 7. 
 
 1798 . 
 
 Extrait d’un memoire de M. Proust, sur le principe 
 tannant. Par le cit. Descostiles. Ann. Chim., 25 , 225. 
 Translation in Repert. Arts and Manuf., 11 , 59 (1799). 
 
 1799 . 
 
 Experiments to determine the Quantity of Tanning 
 Principle and Gallic Acid contained in the Bark of vari¬ 
 ous Trees. By George Biggin, Esq. Phil. Trans., 89 , 
 259. All. Jour. Chem., 5 , 46 (1800). 
 
 Chemische Betrachtungen liber die Wirkung der 
 Beizen beym Rothfarben dcs Kattuns. Yom Burger 
 Chaptal. All. Jour. Chem., 2 , 235. 
 
 Surrogat fiir Gallapfel. Yon Herr Tromer. All. Jour. 
 Chem., 3 , 385 (abstract). 
 
 Surrogat fiir Gallapfel. Yon Herr Prof. Fuchs. All. 
 Jour. Chem., 3 , 739 (abstract). 
 
 Surrogat fiir Gallapfel und Eichenrinde. Yon Herr 
 G. Gray. All Jour. Chem., 1 , 444 (abstract). 
 
 Surrogat fiir Gallapfel. Yon K. E. W. Erbstein. All. 
 Jour. Chem., 4 , 423. 
 
LITERATURE OF THE TANNINS. 
 
 Ill 
 
 1800. 
 
 Rapport (Tun memoire de M. Proust, sur differens 
 points interessans de la Chimie. Par le cit. Yauquelin. 
 Ann. Chim., 35 , 32. All. Jour. Chem., 2 , 252 (1799). 
 
 1801. 
 
 On the production and application of Myrobalans 
 and their use as a substitute for Aleppo Galls. By Dr. 
 Alexander Johnson. Trans. Soc. Arts, 19 , 343. 
 
 Gold Medal for the Preparation of Tan. Trans. Soc. 
 Arts, 19 , 32. 
 
 Resultate der bisher uber den Gerbstoffangestellten 
 Untersuchungen. Yon E. J. B. Karsten. All. Jour. 
 Chem., 7 , 472. 
 
 Yersuche und Bemerkungen uber die Gei’bung des 
 Ober- und Sohlleders durch verscbiedene Yegetabilien, 
 mit Riicksicht auf die quantitativen Yerhaltnisse des 
 darin befindliehen gerbenden Stoffes, ihrer Yerglei- 
 chung gegen die Eichenrinde, und der Zeitraume, 
 welche eine jede dieser Substanzen zum Gahrmacben 
 der Haute erfordert. Yom Dr. Sigismund Friedrich 
 Heraibstadt. All. Jour. Chem., 6 , 415 and 421. 
 
 1802. 
 
 Gold Medal for the Preparation of Tan. Trans. Soc. 
 Arts, 20 , 36. 
 
 Chemische Untersuchung der Rinde der gemeinen 
 weissen Weide. Yom Burger Bartholdi. All. Jour. 
 Chem., 8 , 294; Ann. Chim.. 30 , 268. 
 
 Experiences sur le principe tannant, et reflexions sur 
 l’art du tannage. Par le citoyen Merat Guillot. Ann. 
 Chim., 41 , 323; Repert. Arts and Manuf., 16 , 394. 
 
 Extrait d’un memoire de M. Proust, sur le tannin et 
 ses especes. Ann. Chim., 41 , 92 ; abstract by Bouillon- 
 Lagrange. 
 
112 
 
 THE TANNINS. 
 
 1808 . 
 
 An Account of some Experiments and Observations 
 on the constituent Parts of astringent Vegetables; and 
 on their Operation in Tanning. By Humphry Davy, 
 Esq. Phil. Trans., 93 , 233. 
 
 Schreiben fiber die Identitat der Gallussaure und 
 des G-erbestofFs. Yon Joh. Andr. Scherer. All. Jour. 
 Chem., 10 , 223. 
 
 Gold Medal for the Preparation of Tan. Trans. Soc 
 Arts, 21 , 40. 
 
 1804 . 
 
 Neue Beitrage zu nabern Kenntniss der Matur des 
 Gerbestoffs. Yon J. Bartholma Trommsdorff. ISTeu. 
 All. Jour. Chem., 3, 111; Bepert. Arts, and Manuf. f 2 ], 
 8 , 46, and 129. 
 
 Gold Medal for the Preparation of Tan. Trans. Soc. 
 Arts, 22 , 10. 
 
 Preparation of Tan made in the East Indies from 
 the Bark of the Mangrove Tree. By Dr. James How- 
 ison. Trans. Soc. Arts, 22 , 201. 
 
 1805 . 
 
 Gold Medal for the Preparation of Tan. Trans. Soc. 
 Arts, 23 , 9. 
 
 East India Galls (Aldacay or Caducay Galls). By 
 Dr. William Roxburgh. Trans. Soc. Arts, 23 , 407. 
 
 Ueber die Matur der adstringirenden Substanzen. 
 Meu. All. Jour. Chem., 6, 224 ; taken from second edi¬ 
 tion of Elemens de l’art de la teinture, par C. L. et 
 A. B. Berthollet, tome 1 , p. 104. 
 
 Ueber Darstellung der Gallapfelsaure. Yon Dorffurt. 
 Men. All. Jour. Chem., 6 , 222 (abstract). 
 
LITERATURE OF THE TANNINS. 
 
 113 
 
 Gallapfelsaure von dem Samen des Schmacks. Yon 
 Herr. Fernandes. Neu. All. Jour. Chem., 6 , 231 
 (abstract). 
 
 Beweis der Identitat der Gallussaure und des Gerbe- 
 stoffs. Yon J. F. C. Wuttig. Neu. All. Jour. Chem., 
 6 , 194. 
 
 On an artificial Substance which possesses the prin¬ 
 cipal characteristic Properties of Tannin. By Charles 
 Hatchett, Esq., F.RS. Phil. Trans., 95 , 211 and 285. 
 
 1806. 
 
 Gold Medal for the Preparation of Tan. Trans. Soc. 
 Arts, 24 , 7. 
 
 A third Series of Experiments on an artificial Sub¬ 
 stance which possesses the principal characteristic 
 Properties of Tannin. B 3 ’ Charles Hatchett, Esq., 
 F.R.S. Phil. Trans., 96 , 109. 
 
 1808. 
 
 Ueber die nach Scheele’s, Richter’s und durch Subli¬ 
 mation bereitete Gallapfelsaure. Yon Prof. C. H. Pfaff. 
 Jour. Chem. Physik und Min., 5 , 327. 
 
 Ueber eine Eigenthumlichkeit des Geschmacks der 
 adstringirenden Substanzen. Yon Prof. C. IT. Pfaff. 
 Jour. Chem. Physik und Min., 5 , 331. 
 
 1812. 
 
 Beitrag zur Kenntniss des Gerbstoffs und der Gall¬ 
 apfelsaure. Yon F. Sertiirner. Jour. Chem. Physik, 
 
 4 , 410. 
 
 Courte notice sur le cachou et son analyse, et sur les 
 differentes especes de gomme kino. Par L. Y. Brugna- 
 telli. Bull, de Pharm., 4 , 366. 
 
 10 * 
 
114 
 
 THE TANNINS. 
 
 1818 . 
 
 The Application of Larch-Bark, to answer all the 
 Purposes of Oak-Bark, in Tanning Leather. By 
 Thomas White. Trans. Soc. Arts, 31 , 81. 
 
 1814 . 
 
 Ueber den Chinastoff und die charakterischen Ei- 
 genschaften des Chinaharzes. Yon Prof. 0. H. Pfaff. 
 Jour. Chem. Physik, 10 , 265. 
 
 On Tannin and some new Combinations of the G-allic 
 Acid with Yegetable Substances. By M. Pelletier. 
 Repert. Arts and Manuf. [2], 25 , 304. 
 
 Examen du Rhus typhinum. Par M. John. Jour, de 
 Pharm., 6, 77. 
 
 1815 . 
 
 Ueber die Yerbindung des G-erbestoffs mit dem vege- 
 tabilischen Schleime. Yom Apotheker Grassmann. 
 Jour. Chem. und Physik, 15 , 42. 
 
 1817 . 
 
 Sur les vegetaux astringens, et principalement sur 
 ceux qui sont propres au tannage des cuirs. Par M. 
 Cadet. Bull, de Pharm., 3 , 100; Ann. Chim. et Phys., 
 4 , 404. 
 
 Observations on an Astringent Yegetable Substance 
 from China. By William Thomas Brande. Phil. Trans., 
 107 , 39. 
 
 1818 . 
 
 Lettre de M. Chevreul k MM. les Redacteurs des An. 
 nales de Chimie et de Physique, sur l’acide ellagique 
 de M. Braconnet. Ann. Chim. Phys., 9 , 329. 
 
LITERATURE OF THE TANNINS. 
 
 115 
 
 1819 . 
 
 Die Ratanhiawurzel und ihr Extract. Buch. Rep. 
 Pharm., j; 408 (a review). 
 
 The Application of Chestnut Wood to the Arts of 
 Tanning and Dyeing. By William Sheldon. Am. Jour. 
 Science, i, 312. 
 
 1820 . 
 
 Des galles vegetaux, et des insectes qui les produisent. 
 
 Par MM. D’A.et J.-J. Yirey. Jour, de Pharm., 
 
 6 , 161. 
 
 Invention of an Improvement in the Art of Tanning 
 Hides and Skins and for Barking or Colouring Nets, 
 Sails, and other articles by the Application of certain 
 Materials hitherto unused for that purpose. Patent by 
 William Good. Jour. Arts and Science, i, 97. 
 
 1821 . 
 
 Combination of Apparatus for Extracting a Tanning 
 Matter from Bark and other Substances containing 
 such Tanning Matter. Patent by William Kendrick. 
 Jour. Arts and Science, 2, 171. 
 
 1828 . 
 
 De 1’organisation des tissus vegetaux dans les ex- 
 croissances appelees galles. Par J.-J. Yirey. Jour, 
 de Pharm., g, 314. 
 
 New Material for Tanning from New South Wales— 
 Extract of Mimosa Bark. Jour. Arts and Science, 5 , 
 262 (report of Committee); Repert. Arts and Manuf. 
 [2], 45 , 337 (1824). 
 
 1825 . 
 
 On Tanning and the Use of the Barkometer. By 
 John Burridge. Jour. Arts and Science, 9 , 27. 
 
116 
 
 THE TANNINS. 
 
 Hemlock for Tanning. Jour. Arts and Science, 9 , 
 380. 
 
 On the employment of the Wood and Bark of the 
 Chestnut Tree in Dyeing and Tanning. Repertory of 
 Patent Inventions, 1 , 108. 
 
 1826 . 
 
 Houvelle substance astringente pour la teinture, dite 
 Algarovilla. Par J.-J. Virey. Jour, de Pharm., 12 , 
 296. 
 
 Extracts from Bark. Jour. Arts and Science, 10 , 161. 
 
 1827 . 
 
 Du kino veritable de la Gambie ou de l’Afrique ; de 
 son origine, et des divers sues concrets astringens, usites 
 en medecine. Par M. J.-J. Virey. Jour, de Pharm., 
 13 , 228. 
 
 Ueber den Gerbstoff der Gallapfel, der Eichenrinde, 
 der Chinarinde, des Catechins und des Kinos. Von J. 
 J. Berzelius. Jabresbericht, 7 , 244; Lehrbuch, 6 , 209 
 (edition of 1837); Pogg. Ann., 10 , 257. 
 
 Memoire pour faire suite a l’histoire do la quinine, de 
 la cinchonine, et de l’acide quinique. Par MM. Henry 
 fils et Plisson. Jour, de Pharm., 13 , 268 and 369. 
 
 1828 . 
 
 Ueber kino und extr. ratanhiae araer. Von Prof. 
 Nees v. Esenbeck d. J. Bueh. Repert. Pharm., 27 , 211. 
 
 Bemerkungen fiber den Gerbestoff. Von Dr. J. Waltl. 
 Buch. Repert. Pharm., 27 , 258; Jour. tech, und okono- 
 mische Chem., 2 , 28. 
 
 Ueber den in Europa seit einigen Jahren eingefuhr- 
 ten Farbstoff genannt Bablah. Vom Generallieutenant 
 v. Minutoli. Jour. tech, und okonomische Chem., 2 , 
 475. 
 
LITERATURE OF THE TANNINS. 
 
 117 
 
 Ueber Gerbstoff, Gallapfelsurrogate und Tintenberei- 
 tung. Yom Herausgeber Otto Linne Erdmann. Jour, 
 tech, und dkonomische Chem., 2 , 21. 
 
 Ueber Gallussaure, Gerbstoff und das Eiweiss grlin- 
 farbende Principe der Kaffeebohnen. Yom Prof. C. H. 
 Pfaff. Jour. Chemie und Physik, 4 , 410. 
 
 1829. 
 
 Mode of Extracting Tannin from Bark. Patent by 
 Joseph Giles (April 11 , 1827). Jour. Arts and Science 
 
 [2], 2 , 219. 
 
 1881. 
 
 Untersuchung der Tormentillwurzel auf ihren Ge- 
 halt an Gerbstoff. Yom Dr. C. Sprengel. Jour. tech, 
 und dkonomische Chem., 10 , 40. 
 
 1S82. 
 
 Sur l’acide kinique et sur quelques-unes de ses com- 
 binaisons. Par M. S. Baup. Ann. Chim. Phys., 51 , 56. 
 
 Some preliminary Experiments upon the pod of 
 Cfesalpinia Coriaria, or Dividivi. By Mr. Eodsey. 
 Communicated by Captain Macadam, of the Royal 
 Marines. Edinburgh New Phil. Jour., 1832, 135. 
 
 Chemische Untersuchung der cultivirten Holzarten 
 auf ihre feuerfesten Bestandtheile. Yon Dr. C. Spren¬ 
 gel. Jour. tech, und dkonomische Chem., 13 , 382. 
 
 Bemerkung liber Catechu. Yon Fr. Nees v. Esen- 
 beck. Annalen, 1 , 243. 
 
 Ueber die Zusammensetzung der Chinasaure. Yon 
 Justus Liebig. Annalen, 6 , 14. 
 
 Yersuche liber die Reaction der Gallus- und Gerb- 
 saure, nebst kurzer Bemerkung liber die Natur dersel- 
 ben. Yon Carl Kestler. Buch. Repert. Pharm., 42 , 381. 
 
118 
 
 THE TANNINS. 
 
 Sur la jusee et l’ecorce de chene.—Existence de la 
 pectine dans l’ecorce des arbres. Par M. Henri Bra- 
 connot. Ann. Chim. Phys., 50 , 376; Jour. tech, und 
 okonomische Chem., 13 , 382. 
 
 1883. 
 
 Neueste Entdeckungen iiber die Gerbsaure, oder den 
 sogenannten G-erbstoff. Yon Aug. Wilh. Buchner. 
 Buch. Repert. Pharm., 46 , 316 (a review of the above 
 prize essay). 
 
 Algaroba. Trans. Soc. Arts, 49 , 97. (Papers on 
 Colonies and Trade.) 
 
 1834. 
 
 Memoire sur le tannin et les acides gallique, pyro- 
 gallique, ellagique et metagallique. Par J. Pelouze. 
 Ann. Chim. Phys., 54 , 337 ; Jour. Chim. Med., 10 , 257 ; 
 Pogg. Ann., 29 , 180; Annalen, 10 , 145; Jour. prak. 
 Chem., 2 , 301. 
 
 Ueber die Zusammensetzung der Gerbsaure (Gerbe- 
 stofF) und der Gallussaure. Yon Justus Liebig. Anna¬ 
 len, 10 , 172; Jour. prak. Chem., 2 , 321. 
 
 Ueber die Zusammensetzung der Gerbsaure. Yon J. 
 Pelouze. Annalen, 10 , 210 (aus einem Briefe an J. L.). 
 
 Ueber die salzigen Bestandtheile der Beeren des 
 Gerbersumachs. Yon Dr. J. B. Trommsdorff. Annalen, 
 10 , 328. 
 
 Ueber den Thee. Yon L. C. Marquart. Annalen, 10 , 
 328. 
 
 Ueber Cortex Radicis Ratanhiae. Yon Friedr. Bas- 
 sermann. Annalen, 11 , 226. 
 
 Bemerkung iiber die officinellen Friichte der Eichen. 
 Yon Prof. Dierbach. Annalen, 12 , 85. 
 
 De l’application du tannin pur comme moyen d’al- 
 caloimetrie. Par M. O. Henry. Jour, de Pharm., 20 ,429. 
 
LITERATURE OF THE TANNINS. 
 
 119 
 
 1835. 
 
 Sur la methode de deplacement appliquee au traite- 
 ment do la noix de galle, etc. Par M. Robiquet. Jour, 
 de Pharm., 21 , 113. 
 
 De l’action du tannin sur les bases salifiables or- 
 ganiques, et applications qui en derivent. Par M. 
 Ossian Henry. Jour, de Pharm., 21 , 213; Annalen, 
 15 , 300. 
 
 Ueber die Wirkung des Gerbstoffs und einigen andern 
 Substanzen auf die Wurzeln der Pflanzen. Yon M. 
 Payen. Archiv der Pharm. [2], 2 , 305. 
 
 Memoire coneernant Taction des plantes contenant du 
 tannin, et Taction du tannin lui-meme, sur la propriety 
 vomitive du tartrate antimonial de potasse, et sur di- 
 verses consequences therapeutiques nouvelles. Par M. 
 A. Toulmouche. Jour, de Chim. Med., 10 , 198; Buch. 
 Repert. Pharm., 65 , 97. 
 
 1S86. 
 
 Note sur le tannin. Par M. Leconnet. Jour, de 
 Pharm., 22 , 149; Annalen, 18 , 179. 
 
 On Tanning and Leather Dressing. By A. Aikin. 
 Trans. Soc. Arts, 50 , 192. 
 
 Unters.uchungen des Kateehus und einiger sich daraus 
 bildende Stofl'e. Yon Svanberg. Pogg. Ann., 39 , 161; 
 Jour. prak. Chcm., 10 , 494. 
 
 Notice sur l’acide gallique. Par M. Robiquet. Jour, 
 de Pharm., 22 , 483; Jour. prak. Chem., n, 481. 
 
 Gerbsaures Quecksilberoxydul, Hydrargyrum tanni- 
 cum oxydulatum, Tannas hydrargyrosus. Yon Hein¬ 
 rich Harff. Archiv der Pharm. [ 2 ], 5 , 294. 
 
 Beitrage zur Kenntniss der weinigen Gahrung 
 amylonhaltiger Substanzen. Von H. Ch. Creuzburg. 
 Jour. prak. Chem., 9 , 299. 
 
120 
 
 THE TANNINS. 
 
 1887. 
 
 Improvement in converting hides and skins into 
 leather by the application of matter obtained from a 
 material not hitherto used for that purpose. Patented 
 by William Patterson. Jour. Arts and Science [3], 
 io, 93. 
 
 Ueber Gallae pistacinae. Yon Dr. Th. W. C. Martius. 
 Annalen, 21 , 179. 
 
 Tanningensaure (Catechusaure). Annalen, 24 , 215. 
 
 Du tannin considere sous les rapports de sa pre¬ 
 paration, de son action sur les tissus devenus inertes 
 et sur les tissus vivants ou malades. Par A. Cavarra. 
 Jour, de Pharm., 23 , 88 . 
 
 1838. 
 
 Ueber die Zusammensetzung der Ckinasaure. Yon 
 Alexander Woskresensky. Annalen, 27 , 257. 
 
 Ueber die Zusammensetzung der Gerbsaure. Yon 
 Justus Liebig. Annalen, 26 , 128. 
 
 Faits pour servir a l’histoire de l’acide gallique. Par 
 M. Robiquet. Ann. Chim. Phys. [2], 64 , 385 ; Annalen, 
 25 , 131. 
 
 1889. 
 
 Uebersicht liber die Eichengerbsaure, Gallussaure, 
 Ellagsaure, Brenz- und Melangallussaure. Yon Dr. C. 
 Lowig. Archiv der Pharm. [2], 17 , 57. 
 
 Preparation artificielle du cachou brun. Par M. H. 
 Eeinsch. Jour, de Pharm., 25 , 733 ; Jour. prak. Chem., 
 16 , 509. 
 
 Beitrage zur Kenntniss der Catechusaure. Yon H. 
 Wackenroder. Annalen, 31 , 72. 
 
 Note sur le tannin. Par M. Beral. Jour, de Chim. 
 [2], 5 , 225 ; Archiv der Pharm. [2], 19 , 309 ; Am. Jour. 
 Phar., 1841, 232. 
 
LITERATURE OF THE TANNINS. 
 
 121 
 
 1840. 
 
 Note sur la preparation du tannin. Par M. Duval. 
 Ann. Chim. Phys., 74 , 222; Annalen, 36, 95; Am. Jour. 
 Phar., 1842, 171. 
 
 Sur le cacbou epure du commerce. Par MM. J. Gi- 
 rardin et F. Preisser. Jour, de Pbarm., 26 , 50. 
 
 On the Preparation of Tannin. By Jacob Bell. 
 Phar. Jour. Trans., i, 410. 
 
 1841. 
 
 Nouvelles recherches pour servir a l’histoire de 
 l’acide gallique. Par Antoine Larocque. Jour, de 
 Pharm., 27 , 197. 
 
 Ueber die Idiotypie unkrystallinischer organischer 
 Kdrper, insbesondere der Eichengerbsaure und Humin- 
 saure. Von H. Wackenroder. Jour. prak. Chem., 24 , 18. 
 
 Ueber die Metamorphose der Eichengerbsaure in 
 ihrer wassrigen Losung. Von H. Wackenroder. Jour, 
 prak. Chem., 24 , 28. 
 
 Eigenschaften der Catechusaure nach Untersuch- 
 ungen von H. Wackenroder. Annalen, 37 , 306. 
 
 Ueber Catechin. Von Constantin Zwenger. Anna¬ 
 len, 37 , 320. 
 
 Ueber die Zusammensetzung des Catechins. Von 
 Kobert Hagen. Annalen, 37 , 336. 
 
 Versuche zur kiinstlichen Bildung der Gallussaure 
 oder Umwandlung der Gerbsaure in jene. Vom Prof. 
 Hunefeld. Jour. prak. Chem., 16 , 359. 
 
 Gallus-Handelnotizen. Von Hermann Credner. 
 Archiv der Pharm., [2], 25 , 93. 
 
 1842. 
 
 On Pyrogallic Acid, and some Astringent Substances 
 which yield it. By Dr. John Stenhouse. Mem. Chem. 
 Soc., ij 127 ; Annalen, 45 , 1 . 
 
 11 
 
122 
 
 THE TANNINS. 
 
 On some Astringent Substances as sources of Pyro- 
 gallic Acid. By Dr. John Stenhouse. Mem. Chem. 
 Soc., i, 132. 
 
 1843. 
 
 Examination of Astringent Substances (continued). 
 By John Stenhouse, Esq., Ph.D. Mem. Chem. Soc., i, 
 208. 
 
 Sur la constitution chimique des gallates et tannates 
 de fer et des teintures a base de fer. Par M. Ch. Bar- 
 reswil. Compt.-Rend., 17 , 739 ; Jour. prak. Chem., 30 , 
 379. 
 
 Observations on the Action of Ether on Galls. By 
 Robert Bridges. Am. Jour. Phar., 1843, 40. 
 
 Yorlaufige JNotiz iiber einen rothen Farbestoff als 
 Metamorphose der Gerbsaure aus der Apfelbaumrinde. 
 Yon Ch. Heumann. Buch. Rep. Pharm., 81 , 324. 
 
 Eisengrunender und eisenblauender Gerbstoft. Yon 
 Herr Cavillius. Jahresbericht, 21 , 275; Archiv der 
 Pharm. [2], 36 , 61. 
 
 Recherches sur la composition chimique du the. 
 Par M. Eug. Peligot. Compt.-Rend., 17 , 107 ; Annalen, 
 47 , 358. 
 
 Untersuchung der Gallapfel. Yon Guibourt. Anna, 
 len, 48 , 359; Revue Scient., 13 , 32. 
 
 1844. 
 
 Ueber Gerbestoff; eine Beantwortung der Preisauf- 
 gabe der Hagen-Bucholz’schen Stiftung auf das Jahr 
 1843. Yon Friedr. Muller. Archiv der Pharm. [2], 
 38 , 121 and 266. 
 
 On the Galls of Terebinthus and Pistacia. By M. 
 Guibourt. Phar. Jour. Trans., 3 ? 377 and 381. 
 
LITERATURE OF THE TANNINS. 
 
 123 
 
 On the Chinese Gall, called “ Woo-Pei-Tsze,” and on 
 the Gall of Bokhara, termed “ Gool-I-Pista.” By Jona¬ 
 than Pereira. Phar. Jour. Trans., 3 , 384. 
 
 Memoire sur la preparation du tannin. Par M. Do- 
 mine. Jour, de Phar. Chim. [3], 5 , 231. 
 
 Observations on Catechuic Acid. By John Thomas 
 Cooper, Esq. Phil. Mag. [3], 24 , 500 ; Dingier, 93 , 
 380 ; Jour. prak. Chem., 33 , 429. 
 
 Yergleichende Versuche liber das Gcrben von Kalb- 
 fellen mit Eichenlohe, Dividivi, Catechu und Ellern- 
 rinde. Yon Kampffmeyer. Dingier, 94 , 154. 
 
 Gerbsaure. Yon Hornung. Archiv der Pharm. [2], 
 39, 32 - 
 
 1845. 
 
 Ueber Dividivi. Yon Prof. Dr. Schubarth. Dingier, 
 97 , 316. 
 
 Bericht iiber die Resultate angestellter vergleichen- 
 der Gerbeversuche mit Eichen- und Ellernrinde, Cate¬ 
 chu und Dividivi. Yon W. Kampffmeyer. Dingier, 98 , 
 435. (Aus den Yerhandlungen des Yereins zur Beforde- 
 rung des Gewerbfleisses in Preussen 1845,4te Lieferung.) 
 
 Gallapfel als Gahrungs-Erreger. Yon K. W. G. 
 Kastner. Archiv der Pharm. [2], 44 , 135. 
 
 Gallapfel-Aethei'ol. Yon K. W. G. Kastner. Archiv 
 der Pharm. [2], 44 , 137. 
 
 Ueber Gallussaure und Gerbsaure, Yerhalten dieser 
 Sauren zu Basen, Darstellung, Eigenschaften und Con¬ 
 stitution ihrer wichtigen Salze. Yon Dr. Phil. Buchner, 
 jun. Annalen, 53 , 175 und 349. 
 
 Reagens auf Cbinasaure. Yon Dr. J. Stenhouse. 
 Annalen, 54 , 100. 
 
 Yerhalten von Gerbstoff zu Starke. Yon J. v. Kali- 
 nowsky. Jour. prak. Chem., 35, 201; Annalen, 36, 
 305; Chem. Gaz., 4, 65. 
 
124 
 
 THE TANNINS. 
 
 A New Mode or Method of more expeditiously and 
 effectually Tanning Hides and Skins, and of Extracting 
 and Separating the Catechuic from the Tannic Acid in 
 the Catechu or Terra-Japonica used in Tanning. Patent 
 by Alexander Turnbull. Jour. Arts and Sciences [3], 
 26 , 234. 
 
 1846. 
 
 On the medical and economic Properties of the Rhi- 
 zophora Mangle, or Mangrove Tree. By W. Hamilton. 
 Phar. Jour. Trans., 6 , 11. 
 
 Gallapfel von Terebinthus und chinesische Gallapfel. 
 Yon Guibourt. Archiv der Pharm. [ 2 ], 51 , 190; 
 Revue Scient., March, 1846. 
 
 1847. 
 
 Note on the Means of Testing the Comparative Yalue 
 of Astringent Substances for the Purpose of Tan¬ 
 ning. By Robert Warington, Esq. Mem. and Proc. 
 Chem. Soc., 3 , 319; Chem. Gaz., 5 , 147; Dingier, 104 , 
 316. 
 
 Yergleichende Gerbvcrsuche zwischen Eichenrinde, 
 Ellernrinde, Catechu und Dividivi. Yon W. Kampff- 
 meyer. Dingier, 106 , 323. 
 
 Ueber die Umwandlung der Gerbsaure in Gallussaure. 
 Yon Carl Wetherill. Jour. prak. Chem., 42 , 247 ; Jour. 
 Phar. Chim. [3], 12 , 107; Am. Jour. Phar., 1848, 
 112 . 
 
 Ueber die Natur der Tanninlosung, die bei der Ex¬ 
 traction mit Aether erhalten wird. Yon Dr. Mohr. 
 Annalen, 61 , 352. 
 
 Untersuchung der Kaffeebohnen. Yon Dr. P. Roch- 
 leder. Annalen, 63 , 193. 
 
LITERATURE OF THE TANNINS. 
 
 125 
 
 Ueber die Boheasaure und Gerbsaure der Blatter 
 von Thea bohea. Yon Dr. F. Rochleder. Annalen, 63 . 
 202 . 
 
 Memoire sur les sues astringents connus sous les 
 noms de Cachou, Gambir et Kino. Par M. Guibourt. 
 Jour. Pharm. Cbim. [3], 11 , 24, 260, and 360, and 12 , 37. 
 
 Ueber Gerbsaure. Yon Professor G. J. Mulder. Buch. 
 Rep. Pharm., 101 , 311 (1848), and 102 , 38 (1849). (Aus 
 dem Hollandischen von Dr. Johannes Muller.) Schei- 
 kundig. Onderzoek, IY. Deee, 639 ; Jour. prak. Chem., 
 48 , 90 (1849); Chem. Gaz., 8 , 41 (1850). 
 
 Hote on the Insect forming the Chinese Galls. By 
 Edward Doubleday. Phar. Jour. Trans., 7 , 310. 
 
 1848. 
 
 Ueber die Yeranderung, welche namentlich organi- 
 sehe Stoffe bei ihren Uebergange in den Harn erlei- 
 den. Yon Wohler und Frerichs. Jour. prak. Chem., 44 , 
 60. (From “ Hachrichten v. d. Gottingen A. Universitat 
 und der Konigl. Ges. der Wissenschaften,” 1848, Ho. 5.) 
 
 1849. 
 
 Analyse des glands, suivie de considerations sur la 
 presence du sucre de lait dans les grains des vege- 
 taux. Par M. H. Braconnot. Ann. Chim. Phys. [3], 
 27 , 392; Jour. prak. Chem., 49 , 232. 
 
 Mecca or Bussorah Galls. By Mr. Luekombe. Phar. 
 Jour. Trans., 8, 422; Am. Jour. Phar., 1849, 265. 
 
 Cortex Quercus. Yon Dr. Rutsch. Buch. Rep. 
 Pharm., 104 , 401 (1850). (From “ Centr.-Bl. des land- 
 wirthsch. Yereins in Bayern,” 1849, Nro. 10, 374.) 
 
 Ueber chinesischen Gallus. Yon W. Stein. Dingier, 
 114 , 433, aus Polytech. Centralblatt, 1849, Liefer. 22. 
 
 11 * 
 
126 
 
 THE TANNINS. 
 
 1850. 
 
 Nachtragliche Notiz iiber die chinesischen Gallapfel. 
 Yon Prof. Dr. Schenk. Buch. Rep. Pharm., 105 , 346. 
 
 Observations pratiques sur la preparation du tannate 
 neutre de plomb. Par L. J. Angillis-Mortier. Jour. 
 Pharm. d’Anvers, 6, 417. 
 
 Chinese Galls. By Jacob Bell. Phar. Jour. Trans., 
 10 , 127. 
 
 Ueber sogenannten chinesischen Gallus und seine 
 Bestandtheile. Yon L. F. Bley. Archiv der Pharm. 
 [2], 61 , 297. 
 
 Ueber Bassorah-Gallapfel. Briefliche Notiz von Dr. 
 Bertrand an Dr. Bley. Archiv der Pharm. [ 2 ], 64 , 52. 
 
 Briefliche Notiz iiber chinesische Gallae. Yon Dr. L. 
 F. Bley. Buch. Rep. Pharm., 104 , 80. 
 
 Ueber die chinesischen Gallapfel. Yon Prof. Dr. 
 Schenk. Buch. Rep. Pharm., 105 , 26. 
 
 Untersuchung der Rosskastanie. Yon E. Staffel. 
 Archiv der Pharm. [ 2 ], 64 , 26. 
 
 Bemerkung iiber Knoppern-Extract. Yon Dr. A. 
 Buchner, sen. Buch. Rep. Pharm., 105 , 120. 
 
 1851. 
 
 Moritannic Acid. By Dr. R. Wagner. Chem. Gaz., 
 g, 21; Jour. prak. Chem., 61 , 82. 
 
 Tannaspidic and Pteritannic Acid. By Dr. E. Luck. 
 Chem. Gaz., g, 452; Chem. Central., 1851, 657 and 676. 
 
 On Gambir. By Berthold Seemann. Phar. Jour. 
 Trans., 11 , 576. 
 
 Ueber den Werth der chinesischen Gallapfel. Yon 
 L. A. Buchner, jun. Buch. Rep. Pharm., 107 , 313. 
 
 Istrianische Gallapfel. Von Roder. Chem. Central., 
 1851, No. 24. 
 
LITERATURE OF THE TANNINS. 
 
 127 
 
 1852. 
 
 Zur Lehre vom thierischen Stoffumsatz. Yon H. 
 Eanke. Jour. prak. Chem., 56 , 1. 
 
 The Tannic Acids of the Eubiacese. By F. Eochleder. 
 Chem. Gaz., 10 , 286; from Sitzber. der K. Akad. zu 
 Wien, Jan., 1852. 
 
 Aspertannic Acid. Chem. Gaz., 10 , 61; from Sitz¬ 
 ber. der K. Akad. zu Wien, 1852. 
 
 Ueber die Constitution der Gerbsaure. Yon A. 
 Strecker. (Briefliche Mittheilung.) Annalen, 81 , 248 ; 
 Jour. prak. Chem., 56 , 184. 
 
 Ueber die Gerbsauren und eine Classe neuer stick- 
 stoffhaltiger Abkommlinge der Gerbsaurereihe. Yon 
 Ad. Knop und Dr. W. Knop. Jour. prak. Chem., 56 , 
 327; Chem. Gaz., 10 , 333. 
 
 Ueber die Formel der Moringerbsaure. Yon Prof. 
 Dr. Eud. Wagner. Jour. prak. Chem., 57 , 441; Chem. 
 Gaz., g, 21. 
 
 Sur les tannins et les glucosamides. Par M. Aug. 
 Laurent. Compt.-Eend., 35 , 161; Jour. prak. Chem., 
 57 , 169 . 
 
 Ueber die Bereitung der Gerbsaure. Yon B. San- 
 droek. Archiv der Pharm. [2], 72 , 265. 
 
 Eecherches sur la fermentation gallique. Par M. E. 
 Eobiquet. Compt.-Eend., 35 , 19. 
 
 1858. 
 
 On the Preparation of Gallic Acid from Chinese Gall- 
 nuts. By Dr. G. C. Wittstein. Phar. Jour. Trans., 12 , 
 444. (Aus Yierteljahresschrift fur praktische Pharma- 
 cie, 1853, Heft 1.) 
 
 Zur Geschichte der Entdeck. u. Zusammens. der 
 Gerbsaure. Yon A. Strecker. Jour. prak. Chem., 59 , 
 191 ; Jour. Chem. Soc., 5 , 102. 
 
128 
 
 THE TANNINS. 
 
 Ueber Bestimmung des Gehaltes an Gerbstoff in 
 Gerbmaterialien. Yon Prof. Dr. Fehling. Wurtem- 
 bergiscbes Gewerbeblatt, 1853, No. 38; Dingier, 130 , 
 53 ; Arehiv der Pharm. [2], 78 , 45 ; Chem. Gaz., 12 , 111; 
 Jour. Phar. Chim., 26 , 52. 
 
 Chemische und pharmakologische Priifung des Gum- 
 mi Kino. Yon Dr. C. Hennig. Arehiv der Pharm. [2], 
 73, 129- 
 
 Chemische Untersuchung der sogenannten Bassorah 
 Gallapfel. Yon Di\ L. F. Bley. Arehiv der Pharm. 
 [2], 75, 138. 
 
 Gallotannic Acid, Kinovatannic Acid. By F. Roeh- 
 leder and R. Schwarz. Chem. Gaz., 11 , 308. 
 
 Recherches pour servir a Phistoire des galles (struc¬ 
 ture). Par M. de Lacaze-Duthiers. Compt.-Rend., 36 , 
 
 Yorkommen der Gerbsaure in den Holzpflanzen. 
 Yon Prof. Pettenkofer. Jahrb. der Pharm., i, 360; 
 Jour. prak. Chem., 62 , 508 ; Dingier, 134 , 158. 
 
 Untersuchung der Gallapfelgerbsaure. Yon Adolph 
 Strecker. Annalen, 90 , 328; Jour. prak. Chem., 62 , 
 434; Compt.-Rend., 39 , 49; Am. Jour. Phar., 1855, 49. 
 
 Note sur la constitution moleculaire du tannin et de 
 l’acide gallique. Par M. E. Robiquet. Jour. Phar. 
 Chim. [3], 26 , 29; Am. Jour. Phar., 1855, 51. 
 
 Fabrication des Knoppern-Extracts. Yon Carl Lang. 
 Kunst- und Gewerbeblatt fur Bayern, 1854, 268; Ding- 
 ler, 135 , 156 (1855). 
 
 1855. 
 
 Ueber Darstellung des Tannins aus chinesischen 
 Gallapfeln. Yon Th. Heinecke. Arehiv der Pharm. 
 [2], 83 , 4. 
 
LITERATURE OF THE TANNINS. 
 
 129 
 
 Ueber den praparirten Catechu. Yon Dr. J. J. Pohl. 
 Sitzber. der K. Akad. zu Wien, Band 12 ; Jour. prak. 
 Chem., 64 , 48. 
 
 Ueber Thuja occidentals. Yon A. Kawalier. Sitzber. 
 der K. Akad. zu Wien, Band 13; Jour. prak. Chem., 
 
 64 , 16. 
 
 Ueber die cbinesischen Gelbschoten. Yon M. Y. 
 Orth. Sitzber. der K. Akad. zu Wien, Band 13 ; Jour, 
 prak. Chem., 64 , 10. 
 
 On the Conversion of Tannic Acid into Gallic Acid in 
 the Extracts of Tanning Substances. By Prof. Crace 
 Calvert. Edinburgh New Phil. Jour., 1855, 265 ; Chem. 
 Gaz., 12 , 440 ; Dingier, 136 , 221; Am. Jour. Phar., 
 1856, 455. 
 
 Aphis chinensis. Yon Rebling. Archiv der Pharm. 
 [ 2 ], 81 , 280. 
 
 Ueber den Gerbsauregehalt mehrerer Gallapfelsorten. 
 Yon W. Tod. Archiv der Pharm. [2], 84 , 9. 
 
 1856. 
 
 English Oak Galls. By Dr. Yinen. Phar. Jour. 
 Trans., 16 , 137; from Jour. Linn. Soc., 1856. 
 
 Spaltung der Gerbsaure. Yon Rochleder und Ka¬ 
 walier. Archiv der Pharm. [2], 87 , 57; Chem. Cen¬ 
 tral., 1857, 234. 
 
 Ueber Catechu und dessen Sauren. Yon C. Neu- 
 bauer. Annalen, 96 , 337 ; Jour. prak. Chem., 67 , 257. 
 
 On the Conversion of Tannic into Gallic Acid. By 
 John Horsley. Reports in Brit. Assoc, for Adv. of 
 Science, 1856, 52. 
 
 ISTotiz uber die Gerbsauren. Yon Prof. Rochleder. 
 Sitzber. der K. Akad. zu Wien, 18 , 3 ; Jour. prak. Chem., 
 68 , 405. 
 
130 
 
 THE TANNINS. 
 
 1857. 
 
 Ueber die Entfarbung des gerbstoffsauren Eisen-oxy- 
 duloxyds dimch Oxalsaure. Yon Dr. Geiseler. Archiv 
 der Pharm. [2], 89 , 165. 
 
 Cadmiumtannat. Yon I)r. Hugo Schiff. Annalen, 
 104 , 327. 
 
 Ueber die Gallapfelgerbsaure. Yon Dr. F. Roch- 
 leder. Sitzber. der K. Akad. zu Wien, 22 , 558; Cbem. 
 Gaz., 15 , 228; Am. Jour. Phar., 1856, 464. 
 
 Occurrence of Tannic Acid in Plants. By B. H. 
 Paul. Phar. Jour. Trans., 17 , 174; Am. Jour. Phar., 
 1857, 554. 
 
 1858. 
 
 Improvements in the Production and Application of 
 Tannin or Tannic Acid. Patent by Henry C. Jennings. 
 Jour. Arts and Sciences [3], 8, 158. 
 
 Memoire sur la determination du tannin des vege- 
 taux par les methodes volumetriques. Par M. E. Mo- 
 nier. Compt.-Rend., 46 , 577. 
 
 On the Tannin of Galls. By M. Kawalier. Chem. 
 Gaz., 16 , 421; from Sitzber. der Akad. der Wiss. zu 
 Wien. 
 
 Gelber Farbstoff der griinen Theile von Thuja occi- 
 dentalis. Von Dr. Friedrich Rochleder. Jour. prak. 
 Chem., 74 , 8 . 
 
 Gallapfel-Gerbstoff. Von Dr. Friedrich Rochleder. 
 Jour. prak. Chem., 74 , 28. 
 
 1859. 
 
 Ueber das Yerhalten der Gerbsaure gegen Aether 
 und Wasser. Yon R. Luboldt. Jour. prak. Chem., 
 77 , 357; Am. Jour. Phar., 1860, 322. 
 
LITERATURE OF THE TANNINS. 
 
 131 
 
 Quantitative Bestimmung des Gerbstoffgehalts in 
 gerbstoffhaltigen Korpern, nach der priimiirten Preis- 
 schrift des Apothekers Gustav Muller. Dingier, 151 , 
 69; Cbem. Gaz., 17 , 115; Am. Jour. Pkar., 1859,427. 
 
 On the Estimation of Tannin in some Tanning Ma¬ 
 terials. By John Mulligan and John Dowling. Chem. 
 Gaz., 17 , 430. 
 
 1860. 
 
 Bestimmung der Gerbsaure in den Gerbmaterialien. 
 Yon H. Fleck. Gerberzeitung, 1860, Mr. 2, 3 und 4. 
 
 Yersuch einer allgemeinen Massanalyse fur sammt- 
 licbe Farbstoffe, Gerbstoffe, etc. Yon J. Lowenthal. 
 Jour. prak. Cbem., 81, 150. 
 
 XJeber das Yerbalten des SauerstofiFes zur Gallus- 
 gerbsaure und Gallussaure. Yon C. F. Schonbein. 
 Jour. prak. Chem., 81 , 11. 
 
 Das Yerbalten der Gallapfelgerbsaure gegen Aether, 
 —ein Mittel zum Machweis eines Wassergehalts des 
 letzteren. Yon P. Bolley. Schweiz. Zeit., 5 , 54; 
 Dingier, 157 , 380; Annalen, 115 , 63; Am. Jour. Pbar., 
 1861, 337. 
 
 Tannate de bismuth. Par M. Cap. Jour, de Pharm. 
 d’Anvers, 16 , 170. 
 
 Du tannate de bismuth. Par M. L. Bihot. Jour, 
 de Pharm. d’Anvers, 16 , 363. 
 
 Meue Metbode zur Bestimmung der Gerbsaure. Yon 
 Karl Hammer. Jour. prak. Chem., 81, 159; Dingier, 
 159, 300; Pbar. Jour. Trans. [2], 3 , 433. 
 
 1861. 
 
 Mote on the Supposed Chemical Compound of Tannic 
 Acid, Ether, and Water. By Edward Parrish. Am. 
 Jour. Phar., 1861, 207. 
 
132 
 
 THE TANNINS. 
 
 Die Menge des Gerbstoffs in der Bichenrinde. Yon 
 E. Wolff. Krit. Bl. fur Forst und Jagdw., 44 , 167. 
 
 Titrirmethode zur quantitativen Bestimmung der 
 Gerbsauren. Yon Dr. Robert Handtke. Jour. prak. 
 Cbem., 82 , 345. 
 
 Einfluss der Gerbsaure auf die Weingahrung. Yon 
 Johann Carl Leuchs. Jour. prak. Cbem., 82 , 455. 
 
 Die Blatter von Epacris. Yon Herrn Tonner. Jour, 
 prak. Cbem., 84 , 441. 
 
 Tannin antidote de la strychnine. Par M. Kursak. 
 Repert. Chirn. App., 3 , 99 ; Phar. Jour. Trans. [2], 2 , 227. 
 
 On Some Yarieties of Tannin. By John Stenhouse. 
 Proc. Royal Soc., 11 , 401; Phar. Jour. Trans. [ 2 ], 3 , 
 329; Dingier, 165 , 150; Am. Jour. Phar., 1862, 252. 
 
 1862. 
 
 Satze uber die pliysiologiscke Badeutung des Gerbe- 
 stoffs und der Pflanzonfarber. Yon Wiegand. Bot. 
 Zeitung, 1862, 121. 
 
 On Liquid Diffusion applied to Analysis. By Thomas 
 Graham. Phil. Trans., 1861, 183; Jour. Chem. Soc., 15 , 
 216; Annalen, 121 , 55. 
 
 A Process for Estimating Tannic Acid in Galls. By 
 J. H. Marriage. Phar. Jour. Trans. [2], 3 , 509. 
 
 Sur un extrait astringent de lentisque et de mysthe. 
 Par Albert Schlumberger. Bull. Soc. Muhl., 32 , 316 ; 
 Chem. Central. [2], 8 , 319. 
 
 1868. 
 
 The Tannin Process. By J. W. Davies. Pub. by H. 
 Greenwood, Liverpool. 
 
 English Ink-Galls. By Mr. D’Urban. Phar. Jour. 
 Trans. [ 2 ], 4 , 520. 
 
LITERATURE OF THE TANNINS. 
 
 133 
 
 On the Estimation of Tannic Acid. By Dr. B. W. Ger- 
 land. Chem. News, 8, 54; Am. Jour. Phar., 1863, 519. 
 
 Zur Werthbestimmunggerbsaurehal tiger Materialien. 
 Yon Robert Wildenstein. Zeit. anal. Chem., 2 , 137; 
 Dingier, 172 , 231. 
 
 Ueber die Darstellung des Chinintannats. Yon de 
 Smedt. Jour, de Pharm. d’Anvers, ig, 198; Jour. 
 Pharm. Chim. [3], 44 , 133. 
 
 Zur Kenntniss des gerbsauren Rosanilins. Yon E. 
 Kopp. Jour. prak. Chem., 92 , 241; Chem. News, 7 ,16. 
 
 Zur Bestimmung der Gerbsaure. Yon Dr. H. Risler- 
 Beunat. Zeit. anal. Chem., 2 , 287. 
 
 1864. 
 
 Memoire sur une nouvelle methode de dosage des 
 matieres astringentes vegetales. Par M. Commaile. 
 Compt.-Rend., 59 , 399. 
 
 Beitrag zur volumetrischen Bestimmung der Gerb¬ 
 saure, Gallussaure, sowie des Eisens, Mangans u. s. w. 
 Yon Moritz Mittenzwey. Jour. prak. Chem., gi, 81. 
 
 Die Soja-, Zoga- oder Coua-Rinde als Farbematerial. 
 Yon Prof. Bolley. Jour. prak. Chem., 93 , 361. 
 
 On the Odor of Commercial Tannic Acid. By Wil¬ 
 liam Procter, Jr. Proc. Am. Phar. Assoc., 12 , 255; 
 Am. Jour. Phar., 1865, 53. 
 
 Ueber die Bestimmung der Gerbsaure. Yon Fr. 
 Gauhe. Zeit. anal. Chem., 3 , 122. 
 
 1865. 
 
 Tannin in British Galls. By William Judd. Phar. 
 Jour. Trans. [ 2 ], 7 , 228. 
 
 Zur Bestimmung der Gerbsaure in gerbsaurehalten- 
 den Materialien. Yon W. Hallwachs. Zeit. anal. Chem., 
 5 , 231; from Gewerbeblatt fur das Grossherzogthum 
 Hessen, 1865, Nr. 51 und 52. 
 
 12 
 
134 
 
 THE TANNINS. 
 
 1866. 
 
 Notiz tiber die Blatter von Epacris. Yon Friedrich 
 Rochleder. Jonr. prak. Chem., 98 , 208. Aus dem 53 
 Bde. der Sitzber. der K. Akad. der Wiss. zu Wien. 
 
 Hotiz iiber die Bestandtheile der Wurzelrinde des 
 Apfelbaumes. Yon Dr. Friedricb Rochleder. Jonr. 
 prak. Chem., g8, 205. Aus dem 53 Bde. der Sitzber. 
 der K. Akad. der Wiss. zu Wien. 
 
 Neues Yerfahren zur quantitativen Bestimmung des 
 Gerbstoffs. Yon R. Pribram. Zeit. fiir Chem. [2], 2 , 
 634; from Wittstein’s Yierteljahresschrift, 15 , 520. 
 
 Beitrage zur Kenntniss und zur quantitativen Be- 
 stimmung der Gerbsauren. Yon Prof. Dr. Rudolf Wag¬ 
 ner. Zeit. anal. Chem.. 5 , 1; Jour. prak. Chem., 99 , 294. 
 
 Neues Yerfahren zur Ermittelung des Gerbstoffge- 
 haltesder Loli-Rinde. Yon Prof. Franz Schulze. Ding¬ 
 ier, 182 , 155. 
 
 1867. 
 
 Sur la fermentation gallique. Par M. Ph. Yan Tie- 
 ghem. Compt.-Rend., 65 , 1091. 
 
 Ueber den Gerbstoff von Aesculus Hippocastanum. 
 Yon FT. Rochleder. Archiv der Pharm., 178 , 148. Aus 
 dem Sitzber. der K. Akad. der Wiss. zu Wien. Jour, 
 prak. Chem., 102 , 103. 
 
 Tanninreinigung. Von H. J. Heinz. Phar. Zeit. 
 Russ., 1867, 469. 
 
 Formation of a Substance resembling Artificial Tan¬ 
 nin from Coal. By William Skey. Chem. Hews, 14 , 
 206. 
 
 Ueber die Gerbsaure der Eichenrinde. Yon A. Gra- 
 bowski. Jour. prak. Chem., 102 , 62 (abstr.). 
 
 Untersuchung der Bestandtheile der Tormentillwur- 
 zel. Yon O. Rembold. Jour. prak. Chem., 102 , 62 
 (abstr.). 
 
LITERATURE OF THE TANNINS. 
 
 135 
 
 Ueber einige Gerbsauren. Yon H. Hlasiwetz. An- 
 nalen, 142 , 219; Jour. prak. Chem., 101 , 97. Im Aus- 
 zug. a. d. Sitzber. der K. Akad. der Wiss. zu Wien. 
 
 Ueber die Bestandtheile des Thees. Yon H. Hlasi¬ 
 wetz. Jour. prak. Chem., 101 , 109. 
 
 Chinagerbsaure. Yon O. Rembold. Annalen, 143 , 
 270; Jour. prak. Chem., 103 , 217 (1868). 
 
 Ratanhiagerbsaure. Yon A. Grabowski. Annalen, 
 143 , 274; Jour. prak. Chem., 103 , 219 (1868). 
 
 Filixgerbsaure. Yon G. Malin. Annalen, 143 , 276 ; 
 Jour. prak. Chem., 103 , 221 (1868). 
 
 Filixsaure. Yon A. Grabowski. Annalen, 143 , 279 ; 
 Join*, prak. Chem., 103 , 225 (1868). 
 
 Gerbsiiure der Granatwurzelrinde. Yon O. Rem¬ 
 bold. Annalen, 143 , 285; Jour. prak. Chem., 103 , 229 
 (1868). 
 
 Ueber Aesculus Hippocastanum. Yon Dr. Friedrich 
 Rochleder. Jour. prak. Chem., 101 , 415. A. d. Sitzber. 
 der K. Akad. der Wiss. zu Wien. 
 
 Ueber die Umwandlung der Gallussaure in Gerb- 
 saure. Yon Julius Lowe. Jour. prak. Chem., 102 , 
 111 . 
 
 Darstellung der Aepfelsaure aus den Frnchtzapfen 
 von Rhus coriaria und das verschiedene Yerhalten der 
 Gerbsauren. Yon H. Reinsch. Archiv der Pharm., 
 182 , 153 ; from N. Jabrb. fill* Pharm., 25 , 2. 
 
 Ueber Gallapfel. Yon Archer. Archiv der Pharm., 
 179 , 120 . 
 
 A Critical Examination of the Various Published 
 Processes for the Estimation of Tannin. By Mr. John 
 Watts. Pbar. Jour. Trans. [ 2 ], 8, 515. 
 
 Gerbstoff der Rhabarber (Rheumgerbsaure). Yon 
 Herrn Kubly. Phar. Zeit. Russ., 1867, 603 ; Zeit. fur 
 Chem. [2], 4 , 308. 
 
136 
 
 THE TANNINS. 
 
 Ueber die Beziehungen der Gerbsauren, Glucoside, 
 Pblobaphene und Harze. Von H. Hlasiwetz. Annalen, 
 143 , 290; Jour. prak. Chem., 105 , 360 (1868). 
 
 Ueber das gallussaure Silberoxyd. Von C. Barfoed. 
 Jour. prak. Chem., 102 , 314. 
 
 Ergebnisse bei der Bestimmung der Gerbsaure in 
 einer grosseren Anzahl von Eichenrinden mit Beriick- 
 sicktigung der neueren Methoden. Von Prof. Dr. Buch¬ 
 ner. Dingier, 184 , 250 and 330. 
 
 Studien iiber quantitative Bestimmungs-Metboden 
 der Gerbsauren. Von C. 0. Cech. Inaug.-Diss., Heidel¬ 
 berg, 1867. 
 
 1868. 
 
 Entsteht aus der Gerbsaure des Sumachs, Gallussaure 
 und Pyro-Gallussaure oder nicht? Von Prof. Dr. Bol- 
 ley. Jour. prak. Chem., 103 , 485. 
 
 Ueber die Nadeln von Abies pectinata. Von Fr. Roch- 
 leder. Jour. prak. Chem., 105 , 123; from Sitzber. der 
 K. Akad. der Wiss. zu Wien, Juli, 1868. 
 
 Zur Kenntniss der Korksubstanz. Von M. Siewart. 
 Jour. prak. Chem., 104 , 118. 
 
 Ueber die Kapseln der Rosskastanienfriichte. Von 
 Dr. Fr. Rochleder. Jour. prak. Chem., 104 , 392; 
 “a. d. 57. Bde. Sitzber. der K. Akad. d. Wiss. zu 
 Wien.” 
 
 Ueber einige Bestandtheile der Blatter der Rosskas- 
 tanie. Von Dr. Fr. Rochleder. Jour. prak. Chem., 
 104 , 385 ; “a. d. 57. Bde. Sitzber. der K. Akad. d. Wiss. 
 zu Wien.” 
 
 Sur la formation d’acides gallique et pyrogallique au 
 moyen du tannin de sumac. Par MM. Bolley et Rob. 
 Baehr. Bull. Soc. Chim., 10 , 67 ; from Schweiz. Zeit., 
 1868. 
 
LITERATURE OF THE TANNINS. 
 
 137 
 
 Ueber einige Gerbsauren. Von H. Hlasiwetz. Ueber 
 die Gerbsaure der Eichenrinde. Von A. Grabowski. 
 Ueber die Bestandtheile der Tormentill-Wurzel. Von 
 O. Rembold. Annalen, 145 , 1 and 5; Jour. prak. Chem., 
 105 , 389. 
 
 Ueber die Bildung von Ellagsiiure aus Gallussaure. 
 Von Dr. Julius Lowe. Jour. prak. Chem., 103 , 464. 
 
 Ueber die verschiedenen Methoden zur quantitativen 
 Bestimmung der Gerbsaure. Von C. D. Braun. Zeit. 
 anal. Chem., 7 , 130. 
 
 Zur Gerbsaurebestimmung. Von Tli. Salzer. Zeit. 
 anal. Chem., 7 , 70. 
 
 Ueber einige Benzol-Derivate. Von Friedrich Roch- 
 leder. Jour. prak. Chem., 106 , 293 (1869). “A. d. 58. 
 
 Bde. d. Sitzber. d. K. Akad. d. Wiss. zu Wien.” 
 
 1869. 
 
 Ueber Catechin und Catechugerbstoff. Von Dr. 
 Friedrich Rochleder. Jour. prak. Chem., 106 , 307. 
 “A. d. 59. Bde. d. Sitzber. d. K. Akad. d. Wiss. zu 
 Wien.” 
 
 Ueber einige Bestandtheile der Blatter und Rinde 
 von Cerasus acida. Von Dr. Friedrich Rochleder. 
 Jour. prak. Chem., 107 , 385. “A. d. 59. Bde. d. Sitz¬ 
 
 ber. d. K. Akad. d. Wiss. zu Wien.” 
 
 Ueber den Gerbstoff der Eiche. Von Dr. Theodor 
 Hartig. Stuttgart, Verlag der J. G. Cotta’schen Buch- 
 handlung. (A monograph of 40 pages.) 
 
 Ueber Tannin. Von Otto Facilides. Arehiv der 
 Pharm., 189 , 234. 
 
 Ueber die Bedeutung der Gerbstoffe im Pflanzen- 
 reich (eine phytochemische Abhandlung). Von The- 
 ophil Schmieden. JSTeues Rep. fur Pharm., 18, 257 and 
 321; Pharm. Zeit. Russ., 1869. 
 
 12 * 
 
138 
 
 THE TANNINS. 
 
 Quantitative Determination of the Amount of Tannin 
 in Various Vegetable Astringents. By Henry K. Bow¬ 
 man. Am. Jour. Phar., 1869, 193. 
 
 Die Gerbrinde. Von J. G. Neubrand. J. D. Sauer- 
 lander’s Verlag, Frankfurt a. M., 1869. (A mono¬ 
 graph of 231 pages.) 
 
 On a Comparative Analysis of English and Aleppo 
 Galls. By John Barrow. Chem. News, 19 , 169. 
 
 1S70. 
 
 Ueber die Darstellung des Tannins. Von Oscar 
 Rothe. Archiv der Pharm., 192 , 232. 
 
 Sur la composition de la peau, sur les modifications 
 que le tannage lui fait subir, et sur la fermentation du 
 tannin dans les fosses. Par M. A. Muntz. Ann. China. 
 Phys. [4], 20 , 309. 
 
 Ueber den farbigen Gerbstoff des Erlenbolzes (den 
 Erlenfarbstotf). Von Dr. F. Dreykorn und Prof. Dr. 
 E. Reichardt. Dingier, 195 , 157; Archiv der Pharm. 
 [2], 142 , 215. 
 
 Beurtheilung der analytischen Methoden, welche zur 
 Bestimmung des in Katechu, Ratanhia, Kino und eini- 
 gen anderen gebrauchlichen Droguen vorhandenen 
 Gerbstoffs zur Verfiigung stehen. Von Gunther. Pharm. 
 Zeit. Russ., 1870 ; Chem. Central. [3], 2 , 395 ; Zeit. anal. 
 Chem., 10 , 354. 
 
 Ueber den Gerbstoff der Eiche. Von A. Wolf. In¬ 
 augural-Dissertation, Leipzig, 1870. 
 
 1871. 
 
 Recherches sur la formation de 1’acide gallique. Par 
 M. Sacc. Compt.-Rend., 72 , 766. 
 
 Beitrage zur Kenntniss der im Sumach, in den Myro- 
 balanen und in der Dividivi vorkommenden Gerbsauren. 
 Von N. Gunther. Inaugural-Dissertation, Dorpat, 1871. 
 
LITERATURE OF THE TANNINS. 
 
 139 
 
 Ueber das Verhalten von Starke und Dextrin 
 gegen Jod und Gerbsaure. Yon Victor Griessmayer. 
 Annalen, 160 , 40. 
 
 Ueber Natur und Constitution der Gerbsaure. Yon 
 Hugo Scbiff. Berichte, 4 , 231; Bull. Soc. Chim., 18 , 23. 
 
 Ueber Gerbsaure und einige Derivate derselben. Yon 
 Hugo Schiff. Berichte, 4 , 967. 
 
 Ueber die quantitative Bestimmung des Gerbstoff- 
 gehalts der Eichenrinde. Yon C. Neubauer. Zeit. 
 anal. Chem., 10 , 1. 
 
 1872. 
 
 Ueber reine Gallapfelgerbsaure. Yon Julius Lowe. 
 Zeit. anal. Chem., 11 , 365. 
 
 Bucbarische Gallapfel. Yon E. Palm. Archiv der 
 Pharm., 199 , 233. 
 
 Sur la purification du tannin. Par M. Heinz. Jour. 
 Phar. Chim. [4], 15 , 308. 
 
 Dyes and Dye-Stuffs. By Dr. Crace Calvert. Phar. 
 Jour. Trans. [3], 2 , 596 and 614. 
 
 “Derivate.” Yon Hugo Schiff. Berichte, 291, 
 437, and 642. 
 
 Synthese geschwefelter Gerbsauren. Yon Hugo 
 Schiff. Berichte, 5 , 661 and 731. 
 
 Heue Eeaction auf Alkalien und vice versa auf Gerb¬ 
 saure. Yon Victor Griessmayer. Zeit. anal. Chem., 11 ,43. 
 
 Beitrage zur Technologie der Gerbstoffe. Yon Prof. 
 Dr. Eud. Wagner. Dingier, 205 , 137. From Deutsche 
 Industriezeitung, 1872, Hr. 10 und 11. 
 
 1878. 
 
 Tannic Acid, its Determination, and the Percentage 
 found in some Woods of the Southwest. By Wm. 
 McMurtrie. Ann. Eep. of the U. S. Commissioner of 
 Agriculture, 1873, 181. 
 
140 
 
 THE TANNINS. 
 
 Das Tannin. Von Dr. C. M. Kurtz. Zeit. des Oester- 
 reich. Apotheker-Vereines, n, 56. 
 
 Beziehung zwisohen Catechusaure und Catechugerb- 
 saure. Von Julius Lowe. Zeit. anal. Chem., 12 , 285. 
 
 Estimation of Tannin. By J. M. Merrick. Am. 
 Chemist, 3 , 322, and 4 , 15 and 202 . 
 
 Untersuchungen iiber die Natur und Constitution 
 der Gerbsaure. Von Hugo Schiff. Annalen, 170 , 43 ; 
 Gazz. di Chim., 3 , 353, and 4 , 540. 
 
 Geschwefelte Gerbsaure aus Pbloroglucin. Von 
 Hugo Schitf. Berichte, 6, 26. 
 
 Ueber Sumacbgerbsaure. Von Julius Lowe. Zeit. 
 anal. Chem., 12 , 128. 
 
 Ueber das Vorkommen des Quercetins und Quer- 
 citrins im Catechu und Sumach. Von Julius Lowe. 
 Zeit. anal. Chem., 12 , 127. 
 
 Die Schalung von Eichenrinden. Von W. Wohmann, 
 C. Neubauer und C. A. Lotichius. Wiesbaden, C. W. 
 Kreidel’s Verlag, 1873. 
 
 1874. 
 
 Methode zur Tanninbestimmung mittelst Quecksil- 
 bernitrat. Von J. Macagno. Berichte, 7 , 360. 
 
 Eine Methode zur direkten Bestimmung des Wein- 
 farbstoffs. Von E. Grassi. Berichte, 7 , 359. 
 
 Dosage du tannin, de l’acide gallique et de l’acide 
 pyrogallique. Par M. Maurice Prud’homme. Bull. 
 Soc. Chim., 21 , 169. 
 
 ISTouvel appareil pour doser les tannins contenus dans 
 les diverses matieres astringentes employees dans la 
 tannerie. Par M. A. Terreil. Jour. Phar. Chim. [4], 
 19 , 445 ; Bull. Soc. Chim., 21 , 261. 
 
 Coffee, Chicory, and Tea. By A. H. Allen. Chem. 
 Hews, 29 , 140, 167, 189, and 221. 
 
LITERATURE OF THE TANNINS. 
 
 141 
 
 Dosage du Tannin. Par MM. A. Muntz et Ram- 
 spacher. Bull. Soc. Chim., 22 , 241; Compt.-Rend., 79 , 
 380; Jour. Phar. Chim. [4], 20 , 287; Zeit. anal. Chem., 
 13 , 462. 
 
 On the Estimation of Tannic Acid. By C. Estcourt. 
 Chem. Mews, 29 , 109. 
 
 Preliminary Notice on the Action of Bromine on 
 Protocatechuic Acid, Gallic Acid, and Tannin. By J. 
 Stenhouse. Chem. News, 29 , 95. 
 
 Gerbsaures Eisenoxydul zur Injection von Holz. Yon 
 A. Hatzfeld. Beriehte, 7 , 262. 
 
 Bestimmung der Gerbsaure. Yon Pavesi und Ro- 
 tondi. Beriehte, 7 , 590. 
 
 Procede de dosage comparatif des substances tan- 
 nants. Par E. Schmidt. Bull. Soc. Chim., 21 , 256 ; Zeit. 
 anal. Chem., 14 , 204. 
 
 Sul compostamento dell’ acido tanniconella strato 
 coltivabile. Di M. Mercadante. Gazz. di Chim., 4 , 484. 
 
 The Estimation of Tannin. By C. Estcourt. Chem. 
 News, 30 , 63. 
 
 The Estimation of Tannin. By H. R. Procter. Chem. 
 News, 30 , 78. 
 
 Reaction fur Gerbsaure. Yon H. R. Procter. Be- 
 richte, 7 , 598; Zeit. anal. Chem., 13 , 326. 
 
 Zur Albuminometrie und zur Kenntniss der Tannin- 
 verbindungen der Albuminate. Yon L. Girgensohn. 
 Neues Rep. fur Pharmacie, 22 , 557; Zeit. anal. Chem., 
 13 , 78. 
 
 Catechusaure und Catechugerbsaure. Yon Julius 
 Ldwe. Zeit. anal. Chemie, 13 , 113. 
 
 Observations et experiences pharmacologiques sur 
 le tannate de quinine. Par M. Jules Regnauld. Jour. 
 Phar. Chim. [4], ig, 5. 
 
142 
 
 THE TANNINS. 
 
 1875. 
 
 Die physiologische Wirkung der Gerbsaure in der 
 Pflanze. Yon J. Schel. Bot. Jahrb., 1875, 872. 
 
 Action of Bromine on Protocatechuic Acid, G-allic 
 Acid, and Tannin. By J. Stenhouse. Jour. Chem. Soc., 
 
 28 , 9. 
 
 Estimation of Tannic Acid. By S. J. Simpkin. 
 Chem. Hews, 32 , 11. 
 
 On a Simple Apparatus for the Estimation of Tan¬ 
 nic Acid b}^ the Method of Miintz and Kamspacher. 
 By William Thompson. Chem. Hews, 32 , 310. 
 
 Zur Bestimmung des G-erbstoffs. Yon E. Grassi. 
 Beriehte, 8, 257. 
 
 Sur un procede pour determiner le tannin dans les 
 vins, et sur les stations experimentales en Italie. Par 
 E.-J. Maumene. Bull. Soc. Chim., 22 , 41. 
 
 Ueber die Hatur und Constitution der Gerbsaure. 
 Yon Hugo Schiff. Annalen, 175 , 165; Jour. Chem. 
 Soc., 28 , 1197. 
 
 Synthese geschwefelter Gerbsauren. Yon Hugo 
 
 Schiff. Annalen, 178 , 171; Gazz. di Chim., 6 , 1. 
 
 Huovo metodo per dosare l’acido tannico contenuto 
 nei vini. Di Antonio Carpene. Gazz. di Chim., 5 , 129 ; 
 Beriehte, 8 , 822. 
 
 Ueber die Gerbsaui’e der Dividivi-Schoten und deren 
 Beziehung zur Gallussaure. Yon Julius Lowe. Zeit. 
 anal. Chem., 14 , 35. 
 
 Ueber die Gerbsaure der Myrobalanen und ihre Iden- 
 titat mit der Ellagengerbsaure. Yon Julius Lowe. 
 Zeit. anal. Chem., 14 , 44. 
 
 Ueber die Gerbsaure der Knoppern und ihre Iden- 
 titat mit Gallusgerbsaure. Yon Julius Lowe. Zeit. 
 anal. Chem., 14 , 46. 
 
LITERATURE OF THE TANNINS. 
 
 143 
 
 Ueber die Gerbsaure der Eiche. Von J. Oser. Chem. 
 Central., 1875, 517; Wien. Anz., 1875, 139. 
 
 Beitrage zur Chemie der Eichen-, Weiden und Ul- 
 menrinde. Von Edwin Jobanson. Inaugural-Disser¬ 
 tation, Dorpat, 1875. Druck von C. Mattieson. 
 
 1876. 
 
 On the Estimation of Tannin by Muntz and Ram- 
 spacher’s Method. By Henry R. Procter. Chem. 
 News, 33 , 245. 
 
 An Investigation of Methods of Determining the 
 Tannin of Tea. By J. S. Clark. Am. Jour. Phar., 
 1876, 558. 
 
 Ueber die Anwendung des Tannins bei der Wasser- 
 analyse. Von Hermann Kaemmerer. Jour. prak. 
 Chem., 122 , 322. 
 
 Note surun nouveau procede de titrage des matieres 
 astringentes. Par M. Ferdinand Jean. Bull. Soc. Chim., 
 25 , 511. Berichte, 9 , 730. 
 
 Ueber die Gerbsaure aus den Hopfenzapfen. Von 
 Carl Etti. Annalen, 180 , 223. 
 
 Tanninbestimmung. Von J. Barbieri. Berichte, g, 78. 
 American Tanning Materials. By Wm. McMurtrie. 
 Ann. Rep. of U. S. Commissioner of Agriculture, 1876, 
 52. 
 
 1877. 
 
 Sur les eatechines. Note de M. Arm. Gautier. Compt.- 
 Rend., 85 , 342 and 752. 
 
 Preparation et essai du tannate de quinine. Par M. 
 Stocder. Jour. Phar. Chim. [4], 26 , 418. 
 
 Sur la preparation du tannate neutre de quinine. Par 
 M. P. J. Hooxman. Jour. Phar. Chim. [4], 25 , 420. 
 
 Sur la fixation du tannin par les tissus vegetaux. 
 Par M. Miintz. Jour. Phar. Chim. [4], 26 , 339; Compt.- 
 Rend., 84 , 955. 
 
144 
 
 THE TANNINS. 
 
 On Scientific Research in Relation to Tanning. By 
 Henry R. Procter. Chem. News, 36 , 137. 
 
 Contribuzione alio studio del tannino contenuto nell’ 
 Ilex Paraguayensis. Di Pietro N. Ai*ata. Gazz. di 
 Chim., 7 , 520. From “Anales de la Sociedad Cientifica 
 Argentina.” 
 
 The Relation of Tannin and Gallic Acid. By Thomas 
 Christy. Jour. Soc. Arts, 25 , 456. 
 
 Sur l’oenotannin ou tannin du vin. Par M. A. Gau¬ 
 tier. Bull. Soc. Chim., 27 , 496; Berichte, 10 , 1179. 
 
 Note sur le quebracho, nouvelle matiere tannifere. 
 Par M. Ferdinand Jean. Bull. Soc. Chim., 28 , 6 . 
 
 Des bois tannants et en particulier du Quebracho 
 aspidosperma; application du meme bois a la teinture. 
 Par M. J. Arnaudon. Bull. Soc. Chim., 28 , 524. 
 
 On Some Methods of Estimating Tannins. By Henry 
 R. Procter. Chem. News, 36, 58; Phar. Jour. Trans. 
 [3], 7 , 1020. 
 
 Some Constituents of Hops. By Emery G. Bissell. 
 Am. Jour. Phar., 49 , 582. 
 
 Economic Value of Sumac. Ann. Rep. of U. S. Com¬ 
 missioner of Agriculture, 1877, 13. 
 
 American Sumac. By Wm. McMurtrie. Ann. Rep. 
 of U. S. Commissioner of Agriculture, 1877, 76. 
 
 Sumac. Ann. Rep. of U. S. Commissioner of Agri¬ 
 culture, 1877, 546. 
 
 Dyeing and Tanning Materials. Ann. Rep. of U. S. 
 Commissioner of Agriculture, 1877, 144. 
 
 On the Tannic Acid of Guarana. By Francis V. 
 Green, M.D. Am. Jour. Phar., 49 , 388. 
 
 XJeber die Bestimmung des Gerbstoffs. Von J. Lo- 
 wenthal. Zeit. anal. Chem., 16 , 33 and 201. 
 
LITERATURE OF THE TANNINS. 
 
 145 
 
 1878. 
 
 Beitrag zur Kenntniss einiger Gerbstoff bestimmungs- 
 metboden. Yon Franz Kathreiner. Dingier, 227 , 481, 
 and 228 , 53. 
 
 Ueber die Bestimmung des Gerbstoffs und die Ana- 
 tyse des Thees. Yon Dr. Josef Maria Eder. Dingier, 
 
 229 , 81. 
 
 Tanninbestimmung in der Eichenrinde. Yon E. 
 Perret. Dingier, 229 , 400. From Moniteur Industriel 
 Beige, Jan., 1878. 
 
 Ueber das Quebrachoholz. Yon Dr. Josef Moeller. 
 Dingier, 230 , 481. From Deutsche Industriezeitung, 
 1878, 45. 
 
 Sur les catechines; catechines des gambirs. Par M. 
 Arm. Gautier. Compt.-Rend., 86 , 668 . 
 
 Zur Ivenntniss einzelner chemischer Bestandtheile 
 der Weiden und deren pathologischen Gebilde und 
 iiber einige Reactionen mit Gerbstotfen und denen 
 verwandten Korpern. Yon Edwin JohansOn. Archiv 
 der Pharm., 213 , 103. 
 
 On the Estimation of Tannins. By H. R. Procter. 
 Chem. News, 37 , 256. 
 
 The Estimation of Tannins. By C. Estcourt. Chem. 
 News, 38 , 58. 
 
 Notes on Antimony Tannate. By Ellen S. Richards 
 and Alice W. Palmer. Am. Jour. Sci. and Arts [3], 16 , 
 196 and 361. 
 
 Tanning Materials of South America. By Professor 
 Max Siewart. Jour. Soc. Arts, 26 , 143. 
 
 Extracts of Tannin. Chem. News, 37 , 265; Moni¬ 
 teur Scientifique, May, 1878. 
 
 Sulla preparazione dell’ acido digallico. Del Dr, 
 Pasquale Freda. Gazz. di Chim., 8, 363. 
 
 13 
 
146 
 
 THE TANNINS. 
 
 Bicerche e considerazioni sulla natura glucosidica del 
 tannino naturale delle noci di galla; ( 1 ), e su di una 
 sostanza cristallizzata obtenuta merce l’azione dell’ 
 acido arsenico sull’ aeido gallico. Bel Dr. Pasquale 
 Freda. Gazz. di Chim., 8, 365; Beriehte, n, 1248. 
 
 Notiz iiber einige griechische Gerbmaterialien. Von 
 Hans Jahn. Beriehte, n, 2107. 
 
 Gahrung von Glycose in Gerbsaurelosung. Yon P. 
 Freda und H. Schiff. Beriehte, n, 346 and 2033. 
 
 Gerbstoff bestimmung. Von Herrn Katbreiner. Ding¬ 
 ier, 228 , 53; Beriehte, 11 , 981 and 1137. 
 
 Gerbstoff bestimmung. Von Herrn Eder. Zeit. anal. 
 Chem., ig, 106; Beriehte, 11 , 1932. 
 
 Wattle Bark. Ann. Bep. of U. S. Commissioner of 
 Agriculture, 1878, 507. 
 
 Improvements in the Manufacture of Materials con¬ 
 taining Tannic Acid. By F. G. Yedova. English 
 Patent, No. 2948, July 24, 1878. 
 
 Notes on the Tannins. By B. H. Paul and C. T. 
 Kingzett. Jour. Chem. Soc., 33 , 217. 
 
 Notes on an Abnormal Specimen of Glycerinum 
 Acidi Tannici. By George Masson. Phar. Jour. Trans. 
 [3], 9 , 201. 
 
 A Method of Distinguishing Gallic, Tannic, and Py- 
 rogallic Acids. By William Watson. Phar. Jour. Trans. 
 [3], 9 , 46. 
 
 Tanning Material. Ann. Bep. of U. S. Commissioner 
 of Agriculture, 1878, 93. 
 
 Examinations for Tannic Acid—Analysis of Canaigre 
 Boot. By Peter Collier. Ann. Bep. of U. S. Commis¬ 
 sioner of Agriculture, 1878, 119. 
 
 Examinations of Docks for Tannin. By Peter Col¬ 
 lier. Ann. Bep. of U. S. Commissioner of Agriculture, 
 1878, 121. 
 
LITERATURE OF THE TANNINS. 
 
 147 
 
 Examination of Algarobilla for Tannin. By Peter 
 Collier. Ann. Rep. of U. S. Commissioner of Agricul¬ 
 ture, 1878, 121. 
 
 1879. 
 
 Gerb- und Farbmaterialien. Yon Dr. Josef Moeller. 
 Dingier, 232 , 275, 373, and 478. “Tom Yerfasser 
 gef. eingesendeter Auszug aus dem Berichte iiber die 
 Weltaustellung in Paris, 1878.” 
 
 Ueber das Quebrachoholz. Yon Dr. Josef Moeller. 
 Dingier, 231 , 451. 
 
 Gerbstoffexcurse. Yon W. Eitner. Der Gerber, 5 , 
 
 197. 
 
 Bestimmung des Gerbstoffs und die Analyse des 
 Thees. Yon Josef Maria Eder. Dingier, 230 , 81. 
 
 Chinesische Gallen. Yon Carl Hartwich. Archiv der 
 Pharm., 214 , 524. 
 
 Gambir. Yon Carl Hartwich. Archiv der Pharm., 
 214 , 527. 
 
 Le tannin de l’algarobillo. Par M. R. Godeffroy. 
 Jour. Pharm. Chim. [4], 30 , 71. From “Zeit. des Oes- 
 terreich. Apotheker-Yereines,” March, 1879. 
 
 Osservazioni varie intorno all’acido digallico. Del 
 Prof. Ugo vSchiff. Gazz. di Chim., g, 1 ; Berichte, 12 , 33. 
 
 Yolumetric Estimation of Sulphuric Acid, Tannin, 
 etc. By Ai’thur G. Haddock. Chem. Hews, 39 , 156. 
 
 Sul pretesco acido tannico artificiale. Del Dr. Pas- 
 quale Freda. Gazz. di Chim., g, 327. 
 
 Zur Constitution der Ellagsaure. Yon Hugo Schiff. 
 Berichte, 12 , 1533. 
 
 Beitrag zur Kenntniss einiger Gerbstoff-Bestim- 
 mungsmethoden. Yon Franz Kathreiner. Dingier, 
 227 , 481; Zeit. anal. Chem., 18 ,*112. 
 
148 
 
 THE TANNINS. 
 
 1880. 
 
 Rhatania-tannic acid. Yon Herrn Raabe. Phar. 
 Zeit. Russ., 1880, 577. 
 
 Ueber die Gerbsaure der Eichenrinde. Yon C. Etti. 
 Monatsbefte, I. 262. 
 
 Die Gerberinden. Ein monographischer Beitrag zur 
 tecbnischen Rolistofflehre. Yon Dr. Franz R. v. 
 Hohnel. Berlin, Verlag von Robert Oppenheim. 
 
 Ueber Algarobilla. Yon C. Hartwich. Arcbiv der 
 Pharm., 217 , 281. 
 
 On the Tannic Acid of Sumach Leaves By J. 
 Macagno. Chem. News, 41 , 63; Gazz. di Chim., 11 , 
 297. 
 
 Materials containing Tannin used in Japan. By I. 
 Ishikawa. Chem. News, 42 , 274. 
 
 The Chemistry of Tanning. By Edward Davies. 
 Pbar. Jour. Trans. [3], 10 , 536. 
 
 On the Action of Light and Darkness on Standard 
 Ammonium Chloride and Tannin Solutions. By A. R. 
 Leeds. Jour. Am. Chem. Soc., 2 , 246. 
 
 Ueber Phlobaphen, Eichenroth und Lohgerberei. 
 Yon Dr. Carl Bdttinger. Annalen, 202 , 269. 
 
 The Estimation of Tannin. By Peter Collier. Ann. 
 Rep. of U. S. Commissioner of Agriculture, 1880, 142. 
 
 1881. 
 
 Ueber den Zucker der Eichenrindgerbsaure. Yon C. 
 Bdttinger. Berichte, 14 , 2390; Dingier, 241 , 69. 
 
 Ueber die Gerbsaure der Eichenrinde. Yon Dr. 
 Julius Lowe. Zeit. anal. Chem., 20 , 208. 
 
 Ueber die Bestimmung des Gerbstoffs. Yon A. Leh¬ 
 man. Phar. Zeit. Russ., 1881, 321; Jour. Phar. Chim. 
 [5], 4 , 351. 
 
LITERATURE OF THE TANNINS. 
 
 149 
 
 Yerfahren der Gerbsaure-Extraet-Gewinnung mittels 
 Dialyse. Yon Otto Kohlrausch. Dingier, 240 , 72 
 (abstract from Patent). 
 
 Yerfahren zur Extraction des Tannins. Yon P. 
 Gondolo. Dingier, 240 , -172 (abstract from Patent). 
 
 Ricerche sul tannino contenuto negli organi del Cor- 
 bezzolo, (Arbutus unedo.) Di S. de Luca. Gazz. di 
 Chim., 11 , 487. 
 
 Estimation of Tannin in Tea. By Alfred Hill, M.D. 
 Analyst, 6, 95 and 232. 
 
 Sur la deperdition en tannin des substances tannantes. 
 Par MM. Muntz et Schoen. Jour. Pharm. Chim. [5], 
 4 , 583. 
 
 Sur le dosage du tannin. Par M. Riche. Jour. 
 Pharm. Chim. [5], 3 , 230. 
 
 Zur Gerbstotfbestimmung. Yon Edwin Johanson. 
 Phar. Zeit. Russ., 1881, 577. 
 
 Beitrage zur Kenntniss des Catechins. Yon C. Etti. 
 Monatshefte, 2 , 547. 
 
 Sur le dosage du tannin. Par A. Remont. Jour. 
 Pharm. Chim. [5], 3 , 230. 
 
 On the Estimation of Tannic Acid in Tanning Ma¬ 
 terials. By Nelson H. Darton. Jour. Am. Chem. Soc., 
 4 , 4. 
 
 On the Comparative Yalue of the Several Methods 
 of Determining Tannic Acid. By Nelson H. Darton. 
 Jour. Am. Chem. Soc., 4 , 49 and 62. 
 
 Studio chimico della Persea lingue e del suo tannino. 
 Di Dr. Pietro N. Arata. Gazz. di Chim., 11 , 245. From 
 “ Anales de la Sociedad Cientifica Argentina,” 10 , 193. 
 
 1882. 
 
 New Commercial Plants and Drugs—No. 5. Tan¬ 
 ning Materials. By Thomas Christy. Published by 
 Christy and Co., London, 1882. 
 
 13* 
 
150 
 
 THE TANNINS. 
 
 Zur Gerbstoffbestimmung nach Ldwenthal. Yon 
 Ferd. Simand. Dingier, 244 , 391. 
 
 Zur Bestimmung des Gerbstoffs. Yon A. Lehman. 
 Zeit. anal. Chem., 21 , 414. From Phar. Zeit. Russ., 
 1882, 321. 
 
 Zur Gerbstoffbestimmung. Yon Ferd. Simand. 
 Dingier, 246 , 41 and 133. 
 
 Ueber Algarobilla fur Gerbereizwecke. Yon W. 
 Eitner. Dingier, 244 , 80. 
 
 On the Application of Tannin. By Juste Koechlin. 
 Chem. News, 45 , 112. 
 
 Zur Ermittelung der Gerbsaure in Gerbmaterialien, 
 Lohbruhen und Gerbstoffabfallen. Yon A. Gawalovski. 
 Zeit. anal. Chem., 21 , 552. 
 
 Das Neubauer’sche Yerhaltniss der reducirenden 
 Wirkung von Oxalsaure und Tannin. Yon C. Coun- 
 cler und J. Schroder. Berichte, 15 , 1373. 
 
 Emploi du tannin dans l’analyse des eaux. Par M. 
 A. Jorissen. Jour. Phar. Chim. [5], 6, 289. 
 
 Origin of Tannips. By C. F. Cross and E. J. Bevan. 
 Jour. Chem. Soc., 41 , 106. 
 
 Ueber die Bestandtheile der Blatter von Fraxinus 
 excelsior L. Von Dr. Wilh. Gintl und Friedr. Reinitzer. 
 Monatshefte, 3 , 745. 
 
 Sur le titrage du tannin et de l’acide oenogallique 
 dans les vins. Par M. F. Jean. Compt.-Rend., 94 , 733 ; 
 Bull. Soc. Chim., 38 , 358. 
 
 1883. 
 
 Zur Geschichte der Eichenrindegerbsauren. Yon C. 
 Bottinger. Berichte, 16 , 2710. 
 
 Zur Untersuchung der Gerbstoffextracte. Yon F. 
 Simand. Der Gerber, 9 , 211; Dingier, 251 , 471 (1884). 
 
LITERATURE OF THE TANNINS. 
 
 151 
 
 Ucbersicht der technisch und pharmaceutisch ver- 
 wendeten Gallen. Yon C. Hartwieh. Archiv der 
 Pharm., 221 , 819 and 881. 
 
 Zur Gerbstoffbestimmung. Yon Edwin Johanson. 
 Phar. Zeit. Russ., 22 , 577 ; Zeit. anal. Chem., 23 , 428. 
 
 Tbe Estimation of Tannin. By M. Roques. Phar. 
 Jour. Trans. [3], 14 , 163. From L’Union Pharm., 24 , 
 359. 
 
 Zur Geschichte der Eichenrindegerbsaur-en. Yon C. 
 Etti. Monatshefte, 4 , 512. 
 
 1884. 
 
 Tannin Yalues in the Bark of various Trees of the 
 United States. By S. P. Sharpies. Tenth U. S. Census, 
 9 , 265. 
 
 Yergleichende Untersuchungen uber die Gerbstoffe 
 der Nymphcea alba und odora, Nuphar luteum und 
 advena, Ccesalpinia coriari, Terminalia Chebula und 
 Tunica granatum. Yon Alexander Fridolin. Phar. 
 Zeit. Russ., 1884, 393; Berichte, Ref. 17 , 487. 
 
 Werthbestimmung der Eichenrinde und der Gall- 
 apfel. Yon Franz Musset. Pharm.*Central., 25 , 179 
 and 191; Chem. News, 51 , 41. 
 
 Knoppern. Yon W. Eitner. Der Gerber, 10 , 269; 
 Dingier, 255 , 485 and 487. 
 
 Ueber verschiedene Gerberrinden. Yon C. Counclcr. 
 Gerberzeitung, 1884, 275 and 297 ; Dingier, 255 , 483. 
 
 Eichenholzextract. Yon W. Eitner. Der Gerber, 10 , 
 256. 
 
 Extractgehalt verschiedener Gerbmittel. Yon F. 
 Simand. Der Gerber, 10 , 54 and 173; Dingier, 255 , 
 487. 
 
 Yerhalten der Gerbstoffbriihen beim Kochen. Yon 
 M. Riegel. Der Gerber, 10 , 102; Dingier, 255 , 488. 
 
152 
 
 THE TANNINS. 
 
 Ueber den Gerbstoff der Castanea vesca. Yon Paul 
 Nass. Inaugural Dissertation, Dorpat, 1884. Abstract 
 in Zeit. anal. Chem., 25 , 134. 
 
 Dosage du tannin contenu dans les matieres vege- 
 tales, et principalement dans les ecorces de chene, bou- 
 leau, sapin, quebracho, quinquinas, dividivi, guttes, etc. 
 Par M. Perret. Bull. Soc. Chim., 41 , 22. 
 
 Note sur Faction de Fair sur les dissolutions de tan¬ 
 nin et sur le dosage des tannins. Par M. Antony 
 Guyard. Bull. Soc. Chim., 41 , 336; Chem. News, 50 , 
 26. 
 
 Tea Analysis. By J. P. Geisler. Analyst, 9 , 220 ; 
 from American Grocer. 
 
 Zur Kenntniss der Gerbsauren. Yon O. Nasse. Be- 
 richte, 17 , 1166. 
 
 Observations au sujet du dosage du tannin. Par P. 
 Carles. Jour. Phar. Chim. [5], 9 , 33. 
 
 Sur le tannin de l’ecorce d’aune. Par M. Lamasse. 
 Jour. Phar. Chim. [5], g, 485. 
 
 Estimation of Tannic Acid by Carbonate of Lead. 
 By Robert Jackson. Chem. News, 50 , 179. 
 
 Function of Tannin in Vegetable Cells. By W. 
 Gardiner. Phar. Jour. Trans. [3], 14 , 588; Jour. Chem. 
 Soc. Abstracts, 46 , 1209 ; from Proc. Cambridge Phil. 
 Soc. 
 
 Nuovo processo tannimetrico. Del Prof. Adolfo 
 Casali. Annali di Chimica, 79 , 65. 
 
 Ueber das Verhalten von Tannin und Eichenrinde- 
 gerbsaure gegen verschiedene Reagenzien. Yon C. 
 Etti. Berichte, 17 , 1820. 
 
 Zur Kenntniss der Hemlockgerbsaure. Yon C. Bot- 
 tinger. Berichte, 17 , 1041. 
 
 Ueber Rindengerbsauren. Yon C. Bottinger. Be¬ 
 richte, 17 , 1123. 
 
LITERATURE OF THE TANNINS. 
 
 153 
 
 Erfahrungen iiber die Acetylirung der Gallussaure, 
 des Tannins und deren Anwendung. Yon C. Bdttinger. 
 Berichte, 17 , 1503. 
 
 Eine mikroehemische Eeaktion auf Gerbstoff. Yon 
 J. W. Moll. Berichte, 18 , 84 (Ref.). “ Aus Maandbl. v. 
 Naturw.,” Nov., 1884. 
 
 Yerfahren zum Reinigen vom Gerbstofflosungen. 
 Yon J. Doutreleau und Comp. German Patent 32,632, 
 Oct., 1884. 
 
 Ueber das Yerhalten der Gerbsaure bei der Keimung 
 der Pflanzen. Yon Dr. Rulf. Inaugural-Dissertation, 
 Halle, 1884. 
 
 1885. 
 
 Yerhalten Fehling’scher Losung gegen Tannin. Yon 
 
 A. Sonnenschein, Dingier, 256 , 555; Berichte, 18 , 
 649 (Ref.). 
 
 Die TTntersuchung gebrauchter Lohe. Yon Franz 
 Musset. Phar. Central., 26 , 44. 
 
 Physiologische Bedeutung des Gerbstoffs in Pflanzen. 
 Yon M. Wester maier. Sitzber. der W. Akad. zu Berlin, 
 1885, 1115; Jour. Phar. Chim. [5], 18 , 15. 
 
 Catechu and its Uses for Dyeing and Printing. By 
 Dr. D. Jour. Soc. Dyers and Col., 1 , 94; from Cen- 
 tralblatt fur- die Text. Ind., 3 , 55. 
 
 Bestimmung der freien Sauren in Gerbebruhen. Yon 
 
 B. Kohnstein und F. Simand. Dingier, 256 , 38. 
 Commercial Tannin. By T. Mabern. Phar. Jour. 
 
 Trans. [3], 15 , 850. 
 
 The Gambier and Baros Camphor of Johore. By 
 Peter Macewan. Phar. Jour. Trans. [3], 15 , 793. 
 
 The Quantitative Determination of Tannin. By Dr. 
 F. Becker. Chem. News, 51 , 229. 
 
154 
 
 THE TANNINS. 
 
 Prep, und Anwendung des Catechus als Beize. Yon 
 E. Ziegler. Jahresbericbt, 1885, 2256; Patent—from 
 Moniteur Scientifique [3], 15 , 1250. 
 
 Verfahren zur Gewinnung von Gerbstoffex tract. 
 German Patent 32,693 ; Dingier, 258 , 180. 
 
 Extraction du tannin du bois de chene. Par M. 
 Henry. Revue Scientifique, 36 , 96. 
 
 Note sur un nouveau mode d’essai des matieres tanni- 
 feres. Par M. Ferdinand Jean. Bull. Soc. Chim., 44 ,183. 
 
 Hop Extract. By Wayne B. Bissell. Am. Jour. 
 Phar., 1885, 166. 
 
 Zur Gerbstoffbestimmung nach der Lowenthal’schen 
 Methode. Yon R. Ulbricht. Berichte, 18 , 1116. 
 
 Extractionsapparat fur Gerbmittel und Farbholzer. 
 Patent of F. A. W. Bense. Dingier, 256 , 275. 
 
 Note sur les tannates de mercure. Par M. Charles 
 Castbelaz. Jour. Phar. Chim. [5], 12 , 353. 
 
 Note sur un nouveau proeede de dosage volumetrique 
 du tannin. Par E. Durien. Jour. Phar. Chim. [5], 
 12 , 374. 
 
 Preliminary Note on the Synthesis of Tannin. By 
 Bertram Hunt. Chem. News, 52 , 49. 
 
 Bericht fiber die Yerhandlung der Commission zur 
 Feststellung einer einheitlichen Methode der Gerbstoff¬ 
 bestimmung; geffihrt am 10 Nov., 1883, zu Berlin. 
 Yerlag von Theodor Fischer, Cassel, 1885. Zeit. anal. 
 Chem., 25 , 121 (1886). 
 
 Ueber die Gerbholzextractfabrik in Zupanje. Der 
 Gerber, 11 , 205; Dingier, 259 , 571. 
 
 On the Estimation of Tannin. By Bertram Hunt. 
 Jour. Soc. Chem. Ind., 4 , 263. 
 
 Note on the Destruction of Tannin by Boiling Solu¬ 
 tions of Gambier. By Bertram Hunt. Jour. Soc. Chem. 
 Ind., 4 , 266. 
 
LITERATURE OF THE TANNINS. 
 
 155 
 
 1886. 
 
 Untersuchungen der Gerbsauren der Cortex adstrin- 
 gens Brasiliensis und Siliqua Bablah. Yon Y. Willus- 
 zewitcz. Phar. Zeit. Buss., 25 , 1, 17, and 33; Berichte, 
 19 , 349 (Ref.). 
 
 Heue Gerbstoff bestimmungsmethode. Von Hermann 
 Dieudonne. Cbem. Zeit., 70 , 1076; Berichte, ig, 715 
 (Ref.). 
 
 Unterscheidung des Kastanienholzextract vom Ei- 
 chenholzextract. Yon Wilhelm Eitner und Johannes 
 Meerkatz. Phar. Centralh., 27 , 25; Der Gerber, 11 , 
 193. 
 
 Gerbstoffbestimmung. Yon E. Breutel. Zeit. fur die 
 Chemische Industrie, 1 , 64. 
 
 New Test for Tannic Acid. By J. E. Saul. Phar. 
 Jour. Trans. [3], 17 , 387. 
 
 Houvelle reaction du tannin. Par. J. W. Moll. Jour. 
 Phar. Chim. [5], 14 , 559. 
 
 Hew Tanning Materials. Phar. Jour. Trans. [3], 17 , 
 85. 
 
 Zur Gerbstoffbestimmung, ein Vorschlag. Von E. B. 
 Zeit. anal. Chem., 25 , 527 ; Chem. Hews, 55 , 236. 
 
 Algarobilla, ein naturlicher gelber Earbstoff. Yon G. 
 H. Hurst. Dingier, 262 , 288 ; abstract from Romen’s 
 Jour., 1886, 205. 
 
 Ueber Untersuchung von Gerbstoffen. Yon F. 
 Hotzli. Dingier, 259 , 177, 228, and 272. 
 
 Zur Untersuchung von Gerbstoffextracten. Von F. 
 Simand und B. Weiss. Der Gerber, 12 , 1; Dingier, 
 260 , 564- 
 
 Recent Coutributions to the Estimation of Tannins. 
 By Henry R. Procter. Jour. Soc. Chem. Ind., 5 , 79 
 and 210 . 
 
156 
 
 THE TANNINS. 
 
 Darstellung eines Farbstoffes und eines Gerbmittels 
 aus Katechu. Yon E. Ziegler. Dingier, 262 , 35 ; Ger¬ 
 man Patent, No. 36,472. 
 
 1887. 
 
 Tannin: ils Present and Future Sources. By-Henry 
 Trimble. Jour. Franklin Institute [3], 93 , 442. 
 
 Animal Tannin. By M. Villon. Chem. News, 56 ,175. 
 
 On a Gravimetric Method of Estimating Tannins. 
 By Henry R. Procter. Jour. Soc. Chem. Ind., 6, 94. 
 
 Die Gerb- unci Farbstoff-Extracte. Yon Dr. Stanis¬ 
 laus Mierzinski. A. Hartleben’s Verlag, Wien, 1887. 
 
 Determination of Tannin in Sumach. By J. Ma- 
 cagno. Jour. Chem. Soc. Abstracts, 52 , 624; Chem. 
 Central., 1887, 125. 
 
 On the Estimation of Tannins, with critical Notes 
 on the Methods of Hammer and Lowenthal. B}" 
 Henry M. Rau. Jour. Am. Chem. Soc., 9 , 52. 
 
 Nouveau procede de dosage du tannin. Par M. 
 Villon. Bull. Soc. Chim., 47 , 97. 
 
 Sur un acide tannique contenu dans les baies de 
 sorbier. Par MM. Camill Vincent et Delachanal. Bull. 
 Soc. Chim., 47 , 492. 
 
 Note on Estimation of Tannin in Extracts of Su¬ 
 mac. By T. Chalkley Palmer. Jour. Soc. Dyers and 
 Col., 3 , 175. 
 
 Analysis of some Tannin Matters. By P. Kay and 
 E. Bastow. Jour. Soc. Dyers and Col., 3 , 132. 
 
 Ueber Hemlockextract. Von F. Simand. Der 
 Gerber, 13 , 102; Zeit. Chem. Industrie, 1 , 357. 
 
 Isomerie dell’ aeido tannico. Di Ugo Schiff. Gazz. 
 di Chim., 17 , 552; Berichte, 21 , 524 (Ref.). 
 
 Ueber die Gerbsaure des Eichenholzes. Von Dr. Carl 
 Bottinger. Annalen, 238 , 366. 
 
LITERATURE OF THE TANNINS. 1 57 
 
 Ueber Abkommlinge der Eicheni’indgei'bsaure. Yon 
 Dr. Carl Bottinger. Annalen, 240 , 330. 
 
 Gallusgerbsaures Iiydrochinin. Yon O. Hesse. An¬ 
 nalen, 241 , 273. 
 
 Zur Bestimmung der freien Saure in Gei’bbrxihen auf 
 titriraetrischem Wege. Yon R. Koch. Dingier, 264 , 
 395. 
 
 G-erbstoffbestimmnng. Yon Y. Schroder. Gerber- 
 zeitung, 1887, Nr. 33; Zeit. angw. Chem., 1888, 216. 
 
 1888. 
 
 Gewichtsanalytische Bestimmung der Sauren in 
 Gerbbi’tihen. Yon R. Koch. Dingier, 268 , 329. 
 
 Selbstthatiger Extractionsapparat fur Gerbmate- 
 rialien u. s. w. Yon Dr. R. Koch. Dingier, 267 , 513. 
 
 Zur Weiner gewichtsanalytischen Methode der Be¬ 
 stimmung des GerbstofFes in concentrirter Losung. 
 Yon Dr. R. Koch. Dingier, 268 , 329. 
 
 Zur Simand-Kohnstein’schen Methode der Saure- 
 bestimmxxng in Gerbbruhen. Yon Dr. R. Koch. Ding¬ 
 ier, 269 , 168. 
 
 Dosage du Tannin. Par MM. Ch. Colin et L. Benoist. 
 Moniteur Scientifique [4], 11 , 364; Dingier, 269 , 288; 
 Chem. News, 57 , 214. 
 
 Ueber Differenzen, welche bei Gerbstoff bestimmun- 
 gen entstehen konnen durch wechselnde Ausscheidun- 
 gen schwerloslichen Gerbstotfs. Yon Y. Schroder. 
 Dinglei’, 269 , 38. 
 
 Notes on Gambier. Phar. Jour. Ti’ans. [3], 18 , 863. 
 lleprint from “Tropical Agriculturist,” Feb. 1, 1888. 
 
 Catechxx and Gambier. By Henry Trimble. Proc. 
 Am. Phar. Assoc., 36, 99; Am. Joui*. Plxai\, 1888, 497. 
 
 Gerbstoffbestimmung. Yon F. Simand. Der Gerber, 
 14 , 65; Zeit. angw. Chem., 1888, 216. 
 
 14 
 
158 
 
 THE TANNINS. 
 
 Gerbstoffbestimmung. Yon C. Councler. Gerber- 
 zeitung, 1888, Nr. 14; Zeit. angw. Chem., 1888, 216. 
 
 Ueber das Yorkommen und die Yerteilung des Gerb- 
 stoffs bei den Crassulaceen. Yon E. Wagner. Chem. 
 Central. [3], 19 , 449 (abstract). 
 
 Ueber den Gerbsauregehalt des Sumachs des Kau- 
 kasus. Yon A. Lidovv. Jour. russ. phys.-chem. Gesell., 
 1888 (1), 607; Beriehte, 21 , 889 (Ref.). 
 
 Einwirkung von HC1 auf Tannin. Yon Wehmer und 
 Tollens. Annalen, 243 , 327. 
 
 Ueber Yerbindungen von Leim mit Gerbsaure. Von 
 Dr. Carl Bottinger. Annalen, 244 , 227. 
 
 Einiges liber Gallussaure und Tannin. Von Dr. Carl 
 Bottinger. Annalen, 246 , 124. 
 
 Zur Kritik der Koch’schen Saurebestimmungs-me- 
 thode in Gerbbriihen durch Johann Meerkatz. Yon 
 Dr. R. Koch. Dingier, 267 , 459. 
 
 Zur Chemie der Gerbsauren (1. Abhdlg.). Yon C. 
 Etti. Monatshefte, 10 , 647 and 805. 
 
 Bemerkungen zur Physiologie des Gerbstoffes. Yon 
 Friedrich Reinitzer. Ber. deut. botan. Gesell., 7 , 187; 
 Chem. Central. [4], 1 , 292; Jour. Chem. Soc. Abstracts, 
 58 , 186. 
 
 1S89. 
 
 Reserve Material, especially Tannin, contained in 
 Evergreen Deaves. By E. Schulze. Jour. Chem. Soc. 
 Abstracts, 57 , 540. 
 
 Tannin, its Solubilities, etc. By B. S. Proctor. Phar. 
 Jour. Trans. [3], 20 , 351. 
 
 Zur Bestimmung der Gerbenden Stolfe in sauren 
 Briihen. Yon J. Meerkatz. Der Gerber, 15 , 73. 
 
 Canaigre. By Henry Trimble. Am. Jour. Phar., 
 1889, 397. 
 
LITERATURE OF THE TANNINS. 159 
 
 Die Bestimmung des Gerbstoffs mit Chamaleon. Yon 
 F. Gantter. Zeit. angw. Chem., 1889, 577. 
 
 Ueber die Einwirkung von Luft und Warme auf den 
 Gerbstoff der Weidenrinde. Yon Dr. W. Sonne und 
 Fr. Kutscher. Zeit. angw. Chem., 1889, 508. 
 
 Ueber Benzoyltannin. Yon Dr. Carl Bdttinger. 
 Annalen, 254 , 369. 
 
 Grundlinien zu einer Physiologie des Gerbstoffs. Y on 
 Gregor Kraus. Leipzig, 1889. A monograph of 131 
 pages. 
 
 Acidum Tannicum. Drogisten-Zeitung, Wien, 1889, 
 496. 
 
 On the Tannin in Indian and Ceylon Teas. By David 
 Hooper. Chem. Hews, 60 , 311. 
 
 On some New Tests for Tannic and Gallic Acids. 
 By S. G. Rawson. Chem. News, 59 , 52. 
 
 Estimation of Tea Tannin. By John T. White. 
 Chem. News, 59 , 261. 
 
 Action du borax sur les phenols polyatomiques. 
 Note de M. Aug. Lambert. Compt.-Rend., 108 , 1017. 
 
 1890. 
 
 Les tannoides, introduction critique a l’histoire 
 pbysiologique des tannins et des princies immediate 
 vegetaux qui leur sont chimiquement allies. Par L. 
 Braemer. Lagarde et Sebille, Toulouse, 1890. 150 
 
 pages. 
 
 Distinction entre les tannins a Palcohol et les tan¬ 
 nins a l’eau. Par Adrian. Bull. Soc. Chim. [3], i, 595. 
 
 Etudes sur les bois tannants. Par S.-S. Arnaudon. 
 Moniteur Scientifique [4], 4 , 915. 
 
 Fabrication des tannins decolores. Par M. A. Yillon. 
 Bull. Soc. Chim. [3], 3 , 785. 
 
160 
 
 THE TANNINS. 
 
 Dosage volumetrique du tannin. Par E. Guenez. 
 Compt.-Rend., no, 532; Jour. Phar. Chim. [5], 21 , 
 618. 
 
 Dosage volumetrique du tannin dans les vins. Par 
 MM. L. Roos, Cusson et Giraud. Jour. Phar. Chim. 
 [5], 21 , 59. 
 
 On the Amount of Tannin in Certain Australian 
 Plants. By J. H. Maiden. Jour. Roy. Soc. New South 
 Wales, vol. 21 . 
 
 Function of Tannin in Plants. By M. Biisgen. Jour. 
 Chem. Soc. Abstracts, 58 , 819; Chem. Central., 1890, 
 397. 
 
 Gantter’s Method of Estimating Tannin. By H. R. 
 Procter. Jour. Soc. Chem. Ind., g, 260. 
 
 Bestimmung des Gerbstoffs in Rinden. Yon G. 
 Meyer. Phar. Zeit. Russ., 29 , 820. 
 
 Some American Galls. By Henry Trimble. Am. 
 Jour. Phar., 1890, 563. 
 
 Colorimetric Method for Estimating Tannin in Barks. 
 By Samuel J. Hinsdale. Am. Jour. Phar., 1890, 119 ; 
 Chem. News, 63 , 50. 
 
 Ueber eine neue Reaction des Tannins. Yon Dr. 
 Carl Bbttinger. Annalen, 256 , 341. 
 
 Die Darstellung der reiner Gallusgerbsaure. Yon R. 
 Gartenmeister. German Patent “ 51,326, vom 23. Juni, 
 1889, kl. 12Berichte, 23 , 368 (Ref.). 
 
 Sur un nouveau procede de dosage du tannin par 
 l’iode. Par M. A. Moullade. Jour. Phar. Chim. [5], 22 , 
 153. 
 
 Zur Bestimmung der Gerbstoff im Thee. Yon P. 
 Maltschewsky. Phar. Zeit. Russ., 29 , 427. 
 
 De l’emploi des tannins comme agents desincrustants 
 dans les chaudieres a vapeur. Par Leo Vignon. Bull. 
 Soc. Chim. [3], 3 , 410. 
 
LITERATURE OF THE TANNINS. 
 
 161 
 
 Untersuchung von Canaigre, einer gerbstofFhaltigen 
 Pflanze. Yon Dr. Sigmund KapfF. Farber-Zeitung, i, 
 313 and 335. 
 
 Priifung der Gantter’schen GerbstofFbestimmungs- 
 methode. Yon Prof. Dr. v. Schroder und Dr. J. 
 Passler. Dingier, 277 , 361. 
 
 Zur Klarung und Entfarbung von GerbstofFextracten. 
 Yon A. Folsing. German Patent 53,398; Zeit. angw. 
 Cliem., 1890, 559. 
 
 1891. 
 
 Ueber die GerbstofFe der Algarobilla und der Myro- 
 balanen. Yon. Dr. Georg ZolfFel. Arcbiv der Pharm., 
 229 , 123. 
 
 Canaigre, ein neues Gerbmaterial. Yon W. Eitner. 
 Der Gerber, 17 , 109. 
 
 Die Beziehungen des GerbstofFs zur Pflanzenchemie. 
 Yon Dr. Th. Waage. Phar. Centralb., 1891, 247. 
 
 Ueber Togotorinde. Yon P. Siedler und Th. Waage. 
 Berichte der Phar. Gesell., 1 , 77. 
 
 Was sind GerbstofFe? Yon Th. Waage. Berichte 
 der Phar. Gesell., 1 , 92. 
 
 Estimation of Tannin. By Henry R. Procter. Chem. 
 Hews, 64 , 10. 
 
 A Note on Lowenthal’s Method of Tannin Analysis. 
 By R. L. Whitely and J. T. Wood. Jour. Soc. Chem. 
 Ind., 10 , 523. 
 
 Beitrage zur Analyse des Zuckers und Tannins im 
 Wein. Yon Dr. J. H. Yogel. Zeit. angw. Chem., 1891, 
 44. 
 
 Ueber die Yeranderlichkeit des GerbstofFgebaltes in 
 einigen Gerbmaterialien. Yon Dr. Rudolf Jahoda. 
 Zeit. angw. Chem., 1891, 104. 
 
 14 * 
 
162 
 
 THE TANNINS. 
 
 Die Untersuchung Chinesischen Thees. Yon P. 
 Dvorkovitch. Berichte, 24 , 1945. 
 
 Anleitung zur Bestimmung des wirksamen Gerb- 
 stoffgehaltes in den Naturgerbstoffen. Yon Carl Scherk, 
 jun. A. Hartleben’s Yerlag. Wien, Pest, Leipzig, 1891. 
 
 Heuchera Americana. By Josiah C. Peacock. Am. 
 Jour. Phar., 1891, 172. 
 
 Geranium Maculatum. By Henry Trimble and 
 Josiah C. Peacock. Am. Jour. Phar., 1891, 265. 
 
 Uber die Canaigrewurzel, ein neues Gerbmaterial, 
 und iiber Gerbstoffbestimmung. Yon Dr. A. Klinger 
 und Dr. A. Bujard. Zeit. angw. Chem., 1891, 513. 
 
 Preliminary Note on the Technical Analysis of Gam- 
 bier. By H. R. Procter. Jour. Soc. Chem. Ind., 10 , 681. 
 
 Ueber die Gerbsaure des Eichenholzes. Yon Dr. 
 Carl Bottinger. Annalen, 263 , 109. 
 
 Ueber einige Abkommlinge des Tannins. Yon Dr. 
 Carl Bottinger. Archiv der Pharm., 229 , 439. 
 
 Ueber Myrobalanen. Yon W. Eitner. Der Gerber, 
 17 , 4. 
 
 Transformation de l’acide gallique et du tannin en 
 acide benzoique. Note de M. Ch. - Er. Guignet. 
 Compt.-Rend., 113 , 200. 
 
 Sur la fabrication du jus et des extraits tanniferes. 
 Par Ferdinand Jean. Moniteur Seientifique [ 4 ], 5 , 913. 
 
 Ueber Gallen. Yon C. Hartwich. Phar. Centralh., 
 32 , 588. 
 
 Chestnut-Wood Tannin. By Henry Trimble. Jour. 
 Franklin Institute [3], 102 , 303. 
 
LITERATURE OF THE TANNINS. 
 
 163 
 
 In addition to the foregoing list, the following works 
 contain noteworthy contributions to the subject of the 
 tannins: 
 
 1807. 
 
 Chemisches Worterbuch. Yon Martin Heinrich 
 Klaproth und Friedrich Wolff. Zweiter Band. 
 
 1827. 
 
 Lehrbuch der Chemie. Yon J. Jacob Berzelius. 
 Dritten Bandes, orste Abtheilung. Aus dem Swedischen 
 tibersetzt. Yon F. Wohler. 
 
 1848. 
 
 Ilandbuch der Chemie. Yon Justus Liebig. 
 Abtheilung. 
 
 1845. 
 
 Zweite 
 
 Chemie der organischen Yerbindungen. Yon Carl 
 Lowig. Erster Band. 
 
 1862. 
 
 Hand-Book of Chemistry. * By Leopold Gmelin. 
 Volume 15 . Translated by Henry Watts. 
 
 1S64. 
 
 A Dictionary of Chemistry. By Henry Watts. 
 
 1873. 
 
 Die Rohstoffe des Pflanzenreiches. Yon Julius 
 Wiesner. 
 
 1878. 
 
 The Organic Constituents of Plants and Vegetable 
 Substances. By G-. C. Wittstein. Translated from the 
 German by Baron Fred, von Mueller. 
 
164 
 
 THE TANNINS. 
 
 1882. 
 
 Die Pflanzenstoffe. Yon Aug. Husemann, A. Hilger 
 und Thood. Husemann. 
 
 Physiologische Chemie der Pflanzen. Yon Ernst 
 Ebermayer. 
 
 1884. 
 
 Plant Analysis. By G. Dragendorfif. Translated 
 from the German by Henry G. Greenish. 
 
 1885. 
 
 A Text-Book of Tanning. By Henry R. Procter. 
 
 1886. 
 
 The National Dispensatory. By Alfred Stille and 
 John M. Maisch. Fourth Edition. 
 
 1887. 
 
 Organic Analysis. By Albert B. Prescott. 
 Handworterbuch der Chemie. Yon A. Laden burg. 
 The Principles of Pharmacognosy. By Friedrich A. 
 Fluckiger and Alexander Tschirch. Translated from 
 the Second German Edition by Frederick B. Power. 
 
 1888. 
 
 The Dispensatory of the United States of America. 
 By H. C. Wood, Joseph P. Remington, and Samuel P. 
 Sadtler. Sixteenth Edition. 
 
 A Treatise on Chemistry. By H. E. Roscoe and C. 
 Schorlemmer. Yolume 3 , Part 4. 
 
 1889. 
 
 Commercial Organic Analysis. By Alfred H. Allen. 
 Yolume 3 , Part 1. 
 
LITERATURE OF THE TANNINS. 
 
 165 
 
 1890. 
 
 Handbuch der organischen Cheraie. Yon F. Beil- 
 stein. Zweite Auflage, Dritter Band. 
 
 1891. 
 
 Muspratt’s tbeoretische, praktische und analytische 
 Chemie. Yon F. Stohmann und Bruno Kerb Yierte 
 Auflage, Dritter Band. 
 
 A Hand-Book of Industrial Organic Chemistry. By 
 Samuel P. Sadtler. 
 
INDEX 
 
 Acide tannique, 17. 
 
 Acorn-galls, 61. 
 
 Acraspis erinacei, 63. 
 Alcohol-tannin, 81, 83. 
 
 Aleppo galls, 55, 58. 
 
 American galls, 63. 
 
 Aphis chinensis, 58. 
 
 Assay of tannin infusion, 48. 
 Bassorah galls, 60. 
 
 Bloom, 24. 
 
 Bone tissue, 41. 
 
 Boric acid and tannin, 91. 
 Burgundian galls, 62. 
 
 Burmah galls, 60. 
 
 Catechol, 24, 26. 
 
 Catechu, 25, 37. 
 
 Characters of the tannins, 17. 
 Chestnut, 25. 
 
 Chinese galls, 58. 
 
 Chinese pear galls, 60. 
 Commission of technical chem¬ 
 ists, 43. 
 
 Composition of tannic acid, 94. 
 Constitution of tannic acid, 94. 
 Crystal-tannin, 83. 
 
 Cynips gallte tinctoriae, 55. 
 Cynips isana, 60. 
 
 Cynips Quercus-calycis, 61. 
 Detection of the tannins, 31. 
 Digallic acid, 76, 77, 94, 96, 97, 
 98, 99. 
 
 Discovery of the tannins, 8. 
 Dividivi, 37. 
 
 Eichen-Gerbstolf, 67. 
 
 Ellagic acid, 24, 27, 56. 
 Estimation of the tannins, 31. 
 Ether-tannin, 81. 
 
 Extracts, 22. 
 
 Gallotannic acid, 39, 53. 
 
 Galls, 24, 55. 
 
 Galls, Aleppo, 55, 58. 
 American, 63. 
 
 Analyses of, 57, 58, 59, 60, 
 61. 
 
 Bassorah, 60. 
 
 Burgundian, 62. 
 
 Burmah, 60. 
 
 English, 58. 
 
 French, 62. 
 
 German, 61. 
 
 Greek, 62. 
 
 Hungarian, 62. 
 
 Istrian, 62. 
 
 Italian, 62. 
 
 Japanese, 58. 
 
 Levant, 55. 
 
 Mecca, 60. 
 
 Piedmontese, 61. 
 
 Pistacia, 62. 
 
 Tamarisk, 62. 
 
 Turkish, 55. 
 
 Gelatin methods, 32. 
 
 General characters, 17. 
 Geranium maculatum, 18. 
 Gerhsaure, 17. 
 
 Gerbstoff, 17. 
 
 German galls, 61. 
 
 Greek galls, 62. 
 
 167 
 
168 
 
 INDEX. 
 
 Heuchera Americana, 18. 
 
 Hide powder, 49. 
 
 Hide-powder methods, 32. 
 Holocarpis glohulus, 63. 
 Hungarian galls, 62. 
 
 Hungarian larch, 31. 
 
 Indigo solution, 49. 
 
 Infusion, preparation of the, 
 44. 
 
 Iron-bluing tannins, 20. 
 Iron-greening tannins, 20. 
 Istrian galls, 62. 
 
 Italian galls, 62. 
 
 Japanese galls, 58. 
 
 Ivnoppern, 61. 
 
 Levant galls, 55. 
 
 Mangrove, 25. 
 
 Mecca galls, 60. 
 
 Metallic salts, precipitation by, 
 32. 
 
 Miscellaneous methods, 32. 
 Nutgalls, 55. 
 
 Oak-bark, 37. 
 
 Pathological tannins, 21. 
 Pentacetyl-tannin, 87, 97. 
 Permanganate methods, 32. 
 Permanganate solution, 48. 
 Phlobaplienes, 24, 27. 
 Physiological tannins, 21. 
 Piedmontese galls, 61. 
 
 Pistacia galls, 62. 
 
 Preparation of tannic acid, 78. 
 Properties of tannic acid, 88. 
 Purification of tannic acid, 78, 
 84. 
 
 Pyrogallol, 24, 26. 
 
 Quercitannic acid, 29. 
 
 Quercus alba, 63. 
 
 Austriaca, 62. 
 cerris, 62. 
 ilex, 62. 
 lobata, 63. 
 lusitanica, 55. 
 palustris, 63. 
 pedunculata, 61. 
 robur, 61. 
 sessiliflora, 61. 
 tinctoria, 60. 
 virens, 63. 
 
 Keal’s press, 46. 
 
 Rhatany, 25. 
 
 Rhus glabra, 64. 
 
 Japonica, 58. 
 
 Javanica, 58. 
 
 Rufigallic acid, 23. 
 
 Sampling, 44. 
 
 Schaum-tannin, 81. 
 
 Sodom apple, 61. 
 
 Sumac, 25, 37. 
 
 Tamarisk galls, 62. 
 
 Tamarix articulata, 62. 
 
 Gallica, 62. 
 
 Orientalis, 62. 
 
 Tannates, 92. 
 
 Tannin, 17. 
 
 Tannin extracts, 22. 
 
 Tannin extracts, estimation of, 
 41. 
 
 Terebinthus, 62. 
 
 Turkish galls, 55. 
 
 Valonia, 37. 
 
 Water-tannin, 81.