REVIEWS 227 REVIEWS. SCIENTIFIC AND APPLIED PHARMACOGNOSY. By H. KRAEMER. Philadelphia : H Kraemer, 1915. Price $ 5 . No American pharmacognosist is so well known in Great Britain as Professor Henry Kraemer, and no American is so well qualified as he is to give to the world a work on a subject which he has made his own. Professor Kraemer’s “ Scientific and Applied Pharmacognosy ” represents the best in this field of knowledge that America has yet produced, while his “ Applied and Economic Botany, ” published a short time since, may be regarded as a preliminary study of the fundamental principles and facts upon which pharmacognosy is founded.The book consists of an introduction of eighteen pages, in which the scope, problems, and general principles are set forth, followed by some 836 pages which are devoted to the subject matter.This the author has arranged according to natural orders, a strictly botanical arrangement, but one which his long experience as a teacher has convinced him is the best and most stimulating. The leading char- acters of each natural order are first described, and these are followed by a more or less detailed description of each drug derived from a plant included in the order.These descriptions constitute naturally the most important part’ of the work, and demand careful consideration. Taking an important drug such as belladonna leaves as an example, the botanical and geographical sources are first mentioned; then a detailed description of the leaf, flower, and fruit follows ; next the inner structure of the leaf and stem is described, after which the powder receives careful attention; then the constituents are dealt with, and here not only are the various alkaloids present enumerated and the proportion in various parts of the plant stated, but the constitution of the alkaloids as revealed by hydrolysis is explained; finally the adul- terants (Phytolacca and Scopola leaves) are alluded to.The monograph is accom- panied by numerous illustrations of the leaf, the structure, powder, and so on. The number of drugs dealt with by the author is very large, but it is only the228 REVIEWS more important that are discussed so fully; the less important are more briefly but sufficiently described. Professor Kraemer ’s work is very comprehensive, and will undoubtedly prove an important contribution to the literature of pharmacognosy.Its value would be still further enhanced by careful editing when the second edition is being prepared. For example, on p. 360 the cyanogenetic glucoside of cherry-laurel leaves is called prulaurasin, which is the term now generally employed, while on the opposite page it is called laurocerasin, no mention being made of prulaurasin; on p.686 Vitali’s test for atropine is given in such a manner that the test would probably fail. Numerous similar instances could be cited, and they constitute a blemish which could, and doubtless will, be removed by careful editing. FOOD ANALYSIS. TYPICAL METHODS AND INTERPRETATION OF RESULTS. H. G. GREENISH. By A. G. WOODMAN. First Edition.New York : McGraw-Hill Book Company. 1915. Price 12s. 6d. net. The preface of this book indicates that it has been written to supply a sound course in the analysis of food-stuffs for the use of students, and intended to explain rather more fully than usual the principal standard methods employed in such work. A perusal of the book immediately leads to the conclusion that the author has produced a series of analytical studies which, if carefully and conscientiously worked through under the teacher’s supervision, would start the young food analyst on his iourney with a reliable and sound stock-in-trade of good methods, proper technique, and, further and more important still, of ideas as to how his analytical findings are to be interpreted. I n actual fact there are points in the book which might often be welcome to the more advanced traveller on this road.The methods and style are distinctly American, and frankly a compilation, but the compilation is by one who evident’ly knows what to take and what to leave, and in not a few places the touch of the actual investigator is clearly seen. Very full use has been made of Leach’s standard work, and in every case refer- ences are made to such good text-books of quite cosmopolitan character as will serve to further aid the student when he desires to go deeper into any of his subjects.It is with a sense of gratification that one notices the value that is a;ttached to the Fourth Edition of Allen’s “ Organic Analysis. ” The chapters on General Methods, and especially on the use of the Microscope, are good, and it is pleasant to find the latter instrument introduced to hhe student at the very beginning.Whether the selection of only two such fats as olive oil and butterfat would give a student a proper insight into the methods of tackling such difficult problems as arise in oil and fat analysis may be open to question, but a t least they serve as an introduction t’o most of the more important methods used.The chapter on Milk and Cream may not be quite familiar to English readers, but the methods detailed are sound, and the deductions made from them are quite logically argued, though the student will soon find in practicle that Nature is not always as logical as she theoretically is supposed to be. The same may also be said for the other chapters on Carbohydrate Foods, CocoaREVIEWS 229 and Chocolate, Alcoholic Foods, etc.All contain good standard methods, well and thoroughly described, and the inferences to be made are clearly argued. The book concludes with several pages of very useful (not diagrammatic) photo- micrographs of starches, spices, etc. Errors there are, but they are almost certainly due to oversight in proof-reading, and some of the cross references are misleading, but these do not detract from the general value of the work.It is well printed on good paper, and the illustra- tions are clear and properly reproduced. Altogether it is much above the usual type of work placed in the hands of students. INKS: THEIR COMPOSITION AND MANUFACTURE. By C. A.MITCHELL and T. C. HEPWORTH. Second Edition. Pp. xvi + 266. Sixty illustrations, including four plates. Price 7s. 6d. net. The student of MSS., the jurist, the chemist, the manufacturer, the printer, are all concerned. I n the revised edition of this work Mr. Mitchell has collected much information that must be of great value to each of the above-mentioned. I n a brief but interesting introduction an excellent account is given of the pro- gress of writing and the development of ink manufacture. The descriptions of the oldest types of inks-that is, those containing carbon as the essential constituent-are particularly interesting, and the interest is enhanced by the excellent illustrations showing Chinese methods of manufacture. The date when carbonaceous inks gave place, for ordinary use, to the gall inks is not fixed, as the writer states, but it is reasonable to suppose that the discoveries uf the alchemists had much to do with the change.Indeed, the recipes given in this book for " home-made " inks are strongly suggestive of alchemy. I n dealing with the modern side of the subject Mr. Mitchell has been at pains to collect a large number of interesting and important results, and amongst these must be included those of his own researches.These latter, moreover, are by no means the least important. The sections of the work dealing with the tannins and the determination of their amount in inks is very complete. So, too, are those dealing with printing, copying, and marking inks. Of great interest is the chapter dealing with the examination of writing inks both as fluids and as writing on paper.From the legal point of view the nature of the ink on documents is sometimes of great importance, and to this subject Mr. Mitchell pays considerable attention, without unnecessary detail. The whole book is most readable, and will well repay study by all who are con- cerned with the subject. SAMPLING AND ANALYSING FLUE GASES.By €I. KREISINGER and F. K. OVITZ. 1916. The introduction to this Bulletin states that if is written for the benefit of those in charge of boiler plants and all other persons interested in detailed information con- cerning methods of sampling and analysingflue gases and in the utlillisation of the analy- ses in promoting boiler-house economy. With a view to its being understood by persons CECIL REVIS.London: C. Griffin and Co., Ltd., 1916. The study of inks is important from many points of view. J. P. MILLINGTON. (U.S. Bureau of Mines, Bull. 97, pp. 64.)230 REVIEWS who have not had any instruction in chemistry and phpics, an endeavour has been made to make it complete in itself by a liberal use of illustrations of apparatus, by the provision of worked examples, and by the explanation qf technical terms wherever these are necessarily introduced.So far as any book an accomplish. the difficult purpose the authors had in view, this one must be pr nounced a success. Were it more bulky, there is little doubt that the majority of the class for which it is written would abandon the attempt to master its contents, even if they had the courage to begin.On the other hand, where everything must be explained from the beginning, it would be difficult to shorten the text without risk of making it more difficult to follow, for the book is singularly free from the redundant matter which mars so many elementary treatises of this type and makes them tiresome to read. It may, of course, be questioned whether there is any considerable number of persons with no previous chemical and physical knowledge who could attain much success in the sampling and analysis of flue gases, even if provided with so excellent a little book as this.There are some such persons, no doubt, and the type may be more common in America than in Great Britain, but there may be a larger number who would get erroneous results with a risk of seriously misleading those who put confidence in them.This, however, does not detract from the merit of the book. It is only the range of persons to whom it may be of real service that is in question. There must be, especially just now in this country, many persons who have had some practical instruction from a chemist in routine gas-sampling and analysis, and who now find they have to carry on alone without the periodical guidance of the chemist.To such persons the book should be very useful. and they may find in it many explanations that the chemist may not have thought it necessary to give. I n a book of this type, misprints are of much more importance than in a book written for chemists, who will recognise nine out of ten misprints as such, and not be misled.The writer has only noticed one misprint, on p. 43, where, under a diagram, for “ CO, in flue gases, per cent.,” “ CO, etc.,” should be read. Though written mainly for those with no previous knowledge of the subject, there is matter here of interest to the expert. Thus, experiments are described w,hich support the authors’ opinion that whilst the gases from the uptake of a water-tube boiler form a fairly homogeneous mixture (p. 54), those from a fire-tube boiler can rarely be sampled so satisfactorily that the percentage of carbon dioxide found is certainly within 0.5 per cent. of the true average, even when resort is had to elaborate sampling devices, an error of 1 per cent. being only too common (p. 55). They therefore express the view that it is useless to make analyses closer than to the nearest 0.5 per cent. of carbon dioxide, particularly if no determ nation of the com- bustible gases is made. The very small improvement effected by elaborate sampling devices for collecting gas from many points in the cross-sections of a flue is worthy of note. The difficulty of keeping such devices clean and in working order is well known, and the authors’ experiments suggest that, in some cases at least, they serve no useful purpose. G . C. JONES.