64 REVIEWS REVIEWS. MATERIA MEDICA AND THERAPEUTICS, by J. MITCHELL BRUCE, M.A., LL.D., M.D., F.R.C.P., and WALTER J. DILLINO, M.B., CH.B. Cassell and Company, Ltd., London, 1915. Price 6s. 6d. net. This, the tenth edition of a well-known work, is practically a, new book, arid is a great improvement on previous editions. Pharmacology has made such remarkable progress during the last ten years that a volume of this character becomes useless unless it is completely recast by its authors from time to time.This has now been done, rendering it serviceable to medical and chemical practitioners as well as to students. In it the authors have been a t great pains to make reference to the more important of recent published researches in pharmacology and in the chemistry of medicinal substances.In this work an attempt is made to group drugs in accordance with their pharma- cological actions and therapeutic uses. Such an arrangement is, on the whole, admirable, being, no doubt, of assistance to students of medicine and pharmacy in rapidly appreciating and remembering facts which otherwise are difficult to retain. It also has the merit of making conspicuous by their absence, or by reason of their being classified as of remote activity, those drugs whose claim to therapeutic.value rests only on traditional use, although they are still retained in pharmacopaeias. The relation between chemical constitution and physiological act-ion being remote, and so little understood, it is a pity that the authors divide materia medica into two parts under the headings “ The Inorganic Materia Medica ” and ‘‘ The Vegetable and Animal Materia Medica and Synthetic Preparations,” making a division which is naturally difficult to maintain while at the =me time classifying materia medica in accordance with their therapeutic uses.Notwithstanding a good index, we find that the book suffers from this complex arrangement-for instance, sslvarsan, citric acid, iodoform, and zinc acetate axe dealt with among inorganic substances in Part I., while hydrocyanic acid, chloroform, and zinc valerianate are dealt with in Part 11.Reference is made to most or all of the important synthetic remedies of recent introduction, but the authors wisely omit reference to innumerable synthetic sub- stances of lesser importance which have been introduced, chiefly from Germany, during the last ten years.The introduction contains much which is b d l y expressed from a scientific standpoint, and it is to be hoped that in future editions such generalisations as the following, which are taken at random, will be worded afresh: “ Synthetic compounds are derived from various chemical substances of the carbon series,” ” the, radical glycery1, C3H5 ” ; “ Tabella-Tablets are small flat pieces of choco1at.e containing a minute quantity of an active substance ”; and “ Alkaloids are active nitrogenous principles formed within organic bodies, and may be regarded as compound ammonias.”11. VARIOUS OILSEEDS.REVIEWS 65 Nevertheless, the main part of the book is free from this weakness, a d if is, me think, one of the best of its kind and valuable to students.FRANCIS H. CARR. ELEMENTARY PRACTICAL CHEMISTRY. PART 11. : ANALYTICAL CHEMISTRY, QUALI- TATIVE AND QUANTITATIVE. By FRANK CLOWES, D.Sc., and J. B. COLEMAN, A.R.C.S. Eighth Edition. London: 5. and A. Churchill. 1916. Price 3s. 6d. net8. Amongst the numerous text -books on practical inorganic chcmist>ry, those of Professor Clowes and Mi.J. B. Coleman have secured well-merited recognition, and the issue of an eighth edition of their elementary book on qualitative and quan- titative analysis is a further tribute to the service these authors have rendered to laboratory instruction. In this edition some new matter has been introduced and some alterations in the sequence of subjects have been made.Otherwise it follows the order of pre- vious editions, and comprises qualitative analysis, volumetric and gra;virnetric analysis, inorganic prep&ations, and an appendix containing a number of useful numerical and other data. An ample number of exercises are provided in each of the sections, from which a judicious selection is available according to the varying requirements of students.The relative position of qualitative analysis in the chemistry curriculum of schools and colleges has been the subject of much discussion during recent years, and many teachers consider it preferable that it should be preceded by elementary volumetric work, for it must be recognised that the effective teaching of qualitative analysis both as a training in the methods of observation and as a necessary basis for the further practical study of chemistry necessitates considerable previous knowledge of the subject-matter concerned.It is, however, of course, quite open to teachers and students to vary the order of the curriculum provided in this volume. In the sections dealing with quantitative analysis there are several instances in which the methods described could be advantageously modified so as to bring them more into accord with those of actual practice.For example, under the heading of acidimetry and alkalim.etry, the preparation of normal sulphuric acid is described as the standard acid for me, normal hydrochloric acid being relegated t,o a secondary position, whereas the latter is generally employed and has several distinct advantages.Again, the standardisation of potassium permanganate solution by means of sodiunz oxalate is preferable to the use of metallic iron or of ferrous sulphate, and the volu- metric correlation of potassium dichromate and iodine solutions is also an exercise: of practical value which could be advantageously included. Similarly, in the gravi- metric exercises the use of the Gooch crucible for such estimations as tlhat of silver as silver chloride and of potassium as the chloroplatinate are well within t,he capacity of an elementary student, and are likely to lead to more accurate results than the methods described.The estimation of copper by precipitation with sodium or potas- sium hydroxide is a, further instance of a method that has little to recommend it, and which is but rarely employed.It is only with very great care that accurate results66 REVIEWS can be obtained, and certaidy in the hands of elementary students ignition in accord with precalculation is not an unknown means of arriving at data which will be passed by the censor. Similar criticism might be offered in regard to some of the other exercises de- scribed, but, apart from this point of view, the range and variety of the examples chosen are very good, and the description of the processes concise and clear, so that the book will, without doubt, cont4inue to enjoy the confidence of teachers. CHASES A.KEANE A HANDBOOK FOR CANE-SUGAR MANUFACTURERS AND THEIR CHEMISTS. GUILFORD L. SPENCER, D.Sc. Fifth Edition.93 illustrations. John Wiley and Sons, Inc., New York; Chapman and Hall, London. 1916. $3.50 net. In the fifth edition Dr. Spencer has considerably increased the value of his well- known handbook by amplification of matter and by bringing the subject's dealt with up to date. Treating in the first instance of the physiology and methods of cultivation and reaping of the sugar-cane, the author goes on to give an outline of the general method of manufacture of cane-sugar, dealing with the various stages of the process, including the important subjects of plantation white sugar and the treat- ment of massecuites, in subsequent chapters.The process of refining raw suga.r is then described. The greater part of the work, however, is devoted to the labora- t'ory side of the subject.The various bodies met with in the sugar-cane and its juice are set forth, together with the optical and chemical methods of analysis required for the necessary estimations. Further chapters are devoted to the chemical cpn- trol of the factory and details of sugar-house calculations, and the balance of the work comprises directions for the analysis of the various chemical agents used in sugar-making, with a description of special reagents required in the laboratory of a sugar fwtory, and 140 pages of tables likely t,o be of use to the sugar chemist.Dr. Spencer has compressed an enormous amount of valuable information within the confines of his book, imparted in concise and lucid language. As, however, might be expected from his immediate associations, Louisiana and Cuba loom very largely in his perspective, with the result that a good deal of what ia going on in the outside world has escaped recognition.Thus, he states that the mcst extensive use of seedling canes is in Java, no reference whatever being made to the great work done in this direction in British Guiana, the British West Indies, and Mauritius. The only types of filter-presses he illustrates are American, no mention being made of the almost universal Kroog press, or of the Philippe gravity press.He describes, among plantation white sugar processes, the " nonto " process as a recognised pro- cess, whereas its application to raw juices in the Brazils, Natal, and Java has not been a success. Again, under the heading of multiple evaporation, only the standard centre circulating tube type is referred to; nothing is said as to other and successful types.It is extremely doubtful whether levulose is present in the healthy cane, as Dr. Spencer avers, and his statement that dextran, the high rotating body produced during the growth of Leuconostoc mesenterioidea, is calculated to lead to false resultsREVIEWS 67 in the estimation of sucrose in cane-juice by polarisation does not agree with the experience of Dr.Prinsen Geerligs, the well-known Java expert, who states that dextran is precipitated by the basic acetate of lead used in preparing juice for the polariscope. It is a pity that Dr. Spencer has not had the courage of his opinions, and omitted all reference to the analysis of the sugar-cane as a basis of purchase.After pointing out the impossibility of obtaining a representative sample of cane from truck or cane- carrier, he describes how the cane may be sampled and analysed for this purpose. It is also a pity that such an able exponent of the art of sugar-making should lend his support to inferential methods of obtaining results and to the use of empirical formulze. Thus, he reproduces well-known formulae for calculating the “ available ” sugar from t,he relation of the ‘ b non-sugars ” to t,he sucrose.These non-sugars consist of bodies which not only individually vary in melassigenic properties, but also in the relation of their proportions to one another. Any calculation on the basis of these lumped-together non-sugars must be purely empirical. The true amount of sugar “ available ” for sugar-making purposes is the total quantity present in t.he cane-juice; and, however Utopian i t may seem, it is the entire recovery of this as merchantable sugar which should be the aim of the sugar chemist, not the recognition of a limit of recovery short of this. Again, why should attempts be made to express the composition of “ normal ” juice-that is, the juice without maceration water- by an equally t’ainted formula ? It is not the composition of the “ normal ,’ juice the sugar-maker wants the knowledge of, but of the juice that comes to his hand to be made into sugar. But the cane-sugar-making world is indebted to Dr.Spencer for an excellent and most useful book, the utility of which is aided by the pocket, form in which it is issued and the fine manner in which it is printed and edited.PREDERIC I. SCARD. THE GAS CHEMISTS’ SU:MMARY, 1915. By A. V. HENDRICKSON. London: Walter King. 1916. 3s. 6d. net. The gas industry, for long looked upon as a branch of engineering, is slowly taking its place as a chemical industry. Notwithstanding the great advances made in appliances for the carbonisation of coal and for the distribution of the principal product by engineers, it has been felt that carbonisation itself and the successful working up of products depend upon chemical changes of a by no means simple nature.The second of, it may be hoped, a long series, it presents readable abstracts of papers published in 1915 on subjects more or less directly connected with the industry.The chapter headings are : I. Carbonisation. 11. Condensation, Washing, Puri- fication, Naphthalene and Cyanogen Extraction. IV. Oil and Carburetted Water-Gas. V. Photometry and Calorimetry. VI. Gaseous Heating and Ventilation. VII. Gas Analysis. VIII. Tests. IX. Miscellaneous. There is also a bibliogra,phy. One is surprised to see that Professor Kendall, writing on the anthracite problem, refers t o lime as an exceedingly rare constituent of existing plants, although his view The little book under review is in itseif a symbol of that feeling.111. Tar and Ammonia.68 REVIEWS may be correct that the absence of potash in the ash of anthracite is due to its removal (by solution?) rather than to an original difference, as suggested by the Geological Survey.The work of Jones and Wheeler and of Pam on the carbonisation of the frmtiom of coal obtained by solvents receives full notice. A curious method of stating results of gas analysis in which olefines and ethylene are mentioned separately attracted attention. In the original paper by Jones and Wheeler no clue was found, although the same statement occurred.Earlier papers show that. (higher) olefines are absorbed by ordinary strong sulphuric acid, whereas ethylene is absorbed by bromine. A study by 0. Simmersbach of the effect of the tempera- ture of carbonisation on the fate of nitrogen in coal shows that with increasing temperature more nitrogen comes off as ammoniq, a8 cyanogen, in the tar, and as free nitrogen, much less remaining in the coke at the higher temperatures.Tar and ammonia and the recovery of benzene and toluene naturally receive even more attention than in “ piping times of peace.” One notes that by washing gas with tar the value of the latter can be increased by as much as a penny a gallon, owing to the increase of benzene, toluene, and solvent naphtha. The determination of benzene in gas by Burrell and Robertson’s cryoscopic method is described, but their similar method for petroleum vapour is not mentioned, although their combustion process, based on the convention that the vapour is pen- fane, is alluded to. The method of freezing out, pumping out the fixed gas, and then taking the tension at atmospheric temperature of the residual hydrocarbons, is distinctly good, and available wherever solid CO, or liquid air, as the case may be, is obtainable. J. T. Durn points out, as the writer has done, that the so-called net calorific value of gas is purely arbitrary, inasmuch &B aU products of combustion other than water are ignored. The book is interesting and full of matter, on the whole well selected, although the author is entirely uncritical in his abstracts. The misprints me few but striking. J. H. COSTE.