March 26 1903] 



NA TURE 



48 = 



why they should be so singled out is not stated. There 

 is a considerable collection of development formulae in 

 addition to the above, but only one here and there has 

 the name of its author attached. It would have been 

 better if the author's name had been given in every 

 case, with a reference to the source whence the formula 

 was obtained. Various fixing solutions are given, 

 neutral and acid, one including "acetone-sulphite," 

 but alkaline fixing baths are not represented. Among 

 " stain removers," too, weak alkaline solutions do not 

 appear to be mentioned, though they are the best 

 solvents of the coloured oxidation products of develop- 

 ing reagents. 



In a lew cases the compiler has ventured to state that 

 one or the other formula is " the best," without quoting 

 any authority or giving any reason for the preference. 

 Among " hypo, eliminators," for example, " the best 

 is plain water," but potassium percarbonate " is the 

 best chemical destroyer of hypo." A soluble hypo- 

 chlorite was the first " hypo, eliminator " suggested, 

 now many years ago, and it remains unsurpassed, if 

 equalled. It is, however, not mentioned here, and its 

 omission is not due to the ease with which, if carelessly 

 used, it attacks the silver image itself, because sodium 

 hypochlorite is given as a stain remover. 



Kach of the thirty-three chapters is on a different 

 subject, ranging from " The Studio " and " The Work- 

 room," and the various operations that are generally 

 understood as practical photography, to the " Facts of 

 Copyright" and "Toilet and Hygiene." This last 

 section treats of stained finger-nails; eyes affected bv 

 the coloured light of the dark room ; skin irritation 

 caused bv developers, potassium bichromate, &c. ; and 

 similar subjects. The volume is full of information, 

 and cannot fail to prove useful to the photographer who 

 keeps it at hand. 



U. S. Department of Agriculture. Field Operations of 

 the Bureau of Soils, 1901. Third Report. Pp. 

 647 + case containing thirty-one maps. (Washington : 

 Government Printing Office, 1902.) 



The book under notice constitutes the third of the series 

 of reports on the work of the Division of Soils, which 

 is engaged in mapping the distribution and describing 

 the agricultural characteristics of the various soil types 

 met with in selected areas of the United States. The 

 general scope of this remarkable undertaking has 

 already been discussed in these columns when reviewing 

 the Report of 1900 (Nature, November 6, 1902) ; the 

 present volume shows that the work of the Division 

 has so far been appreciated by Congress that its pro- 

 gress has been assisted by increased appropriations, 

 enabling it to enlarge its working staff and cover a 

 greater area in its annual survey. The reports now 

 presented deal with the most diversified types of land, 

 and speak of the variety in the conditions under which 

 farming is carried out in the United States. On the 

 one hand, we read of intensive systems of agriculture, 

 analogous to our own, as in New Jersey and Pennsyl- 

 vania, old settled districts in touch with large centres 

 of population, farming high, and either purchasing 

 fertilisers or keeping stock to make manure ; then we 

 pass, as a 'contrast, to parts of Virginia and Georgia, 

 which were ruined by the war and left without capital 

 or energy, where it is still the custom to crop out the 

 soil by continuously growing corn or wheat, and then 

 clear a fresh farm, leaving the old land to fall back to 

 scrub until it accumulates sufficient decayed vegetable 

 matter to be worth breaking up again. 



In the western States the contrasts are just as great 

 between the arid regions, which are still " dry farmed," 

 and can only produce a crop of barley or wheat everv 

 other season, the land being fallowed in the intervening 



NO. 1743, VOL. 67] 



years to gather two years' rainfall for the needs of one 

 crop, and the rich irrigated land of California, famous- 

 for oranges, apricots, and other valuable fruits. 



Two 01 the most interesting crops which come in for 

 notice in this book are tobacco and sugar beet ; in both 

 cases the industry is being very rapidly developed in the 

 United States; indeed, the production of beet sugar is 

 an affair of the last two or three years only, and the 

 expansion has been largely brought about by the energy 

 and advice of the Division of boils. Anyone seeking 

 a striking example of the way a State can utilise scien- 

 tific research for the fostering of a national industry 

 cannot do better than study the work on tobacco of 

 the United States Department of Agriculture. • 



Interesting as these volumes are to the agriculturist 

 from the variety of the crops and the farming conditions 

 described, they are equally valuable to many students 

 of pure science ; to the botanist they form a treatise on 

 what might be called applied ecology, to the chemist 

 and physicist the " alkali land " problems will appeal; 

 the geographer will find illustrations, often accom- 

 panied by excellent photographs, of the most varied 

 types of land surface and the changes to which they are 

 subject ; while the economist, as noted above, may ob- 

 tain abundant material for his special study. An ac- 

 companying report sets the whole cost of the Division 

 of Soils as a little under 8000/. for the year 1901 ; of 

 this, the Soil Survey, exclusive of laboratory work, 

 required a little less than half, 3-53 dollars per square 

 mile for the 5596 square miles covered in the year, or 

 almost exactly a farthing per acre, not an excessive 

 charge on the capital value of the land ! A. D. H. 



Theoretical Organic Chemistry. By J. B. Cohen, Ph.D. 

 Pp. xv + 57S. (London : Macmillan and Co., Ltd., 

 1902.) Price 6s. 



The author commences his preface with an apology for 

 bringing out a new book on organic chemistry. We 

 are not, however, prepared to agree with Dr. Cohen 

 that an apology is necessary. There are not very many 

 good and complete text-books on organic chemistry in 

 this country, therefore a new book — provided that it 

 is good — would not be at all out of place. At another 

 place in his preface the author says, " The production 

 and uses of common materials, which come under our 

 daily observation, are frequently relegated in some 

 text-books of organic chemistry to a background of 

 small print; in others entirely omitted." Dr. Cohen 

 particularises such substances as lanoline, linseed oil. 

 gelatine, the tannins, turpentine, &c. Our interest is. 

 at once aroused and we turn up turpentine, and this is. 

 what we find : 



" Turpentine oil is used as a solvent in the prepara- 

 tion of varnishes, for mixing with pigments, as an 

 embrocation, &c. It absorbs oxygen, when heated 

 in presence of water, and the oxygenated water is em- 

 ployed as a disinfectant and deodoriser." 



There is very little here about the production of tur- 

 pentine. We then turn to linseed oil ; here we are 

 more fortunate, because there are seventeen lines de- 

 voted to telling us that the oil may be used for preparing 

 linoleum, oil-cloth, and. that it is employed in making 

 varnishes and paints — but not a word as to its pro- 

 duction. Again, the treatment of gelatine, tannin and 

 lanoline can scarcely be called exhaustive. We are 

 not at all sure that it is desirable in a text-book, the 

 size of the one before us, to describe such substances 

 in detail, but when the author lays claim to treat them 

 more fully than they are treated in other text-books, 

 one is rather surprised to find them dismissed with 

 such scanty notices. 



Of course, details of this kind do not condemn a- 

 book, and. in many respects, the book is very good. 



