9 6 



SCIENCE. 



BOOKS RECEIVED. 



A Manual of Zoology for the use of students, with 

 a general introduction on the principles of Zoology — by 

 Henry Alleyne Nicholson, M. D., D. Sc., Ph. D., 

 etc., Professor of Natural History in the University of St. 

 Andrews. Sixth edition, revised and enlarged,. William 

 Blackwood and Sons — Edinburgh and London, 1880. 



This Manual of Zoology has become so fully recognized 

 as one of the most complete and reliable guides to a 

 knowledge of this subject, that but few words are neces- 

 sary in giving notice of the issue of a new edition. 



The study of Zoology is constantly bringing new and 

 interesting facts to the surface, hence the necessity for fre- 

 quent editions of manuals treating on the subject, to keep 

 pace with discoveries. Professor Nicholson has availed 

 himself of the present opportunity to thoroughly revise his 

 work, and bring forward arrears of facts which have ac- 

 cumulated during the past two years, and in accordance 

 with the views of many distinguished naturalists he has 

 raised the order of Echinodermata to the rank of a sub- 

 kingdom. This alteration necessitates the abandonment 

 of the Annuloicta as a sub-kingdom, and the reference of 

 tne Scoiecida to the Annulosa. 



Professor Nicholson forestalls criticism for such action 

 by candidly admitting that this arrangement is far from 

 being wholly satisfactory, but asks that it may be provis- 

 ionally adopted as the best under the circumstances, tak- 

 ing into account our present knowledge. 



A number of excellent illustrations have been intro- 

 duced in the present edition, and the student will now 

 have the benefit of over 450 wood-cuts. 



The general plan of this book is admirable, and follow- 

 ing each chapter is a list of the best works and memoirs 

 relating to the animals belonging to each sub-kingdom. 



There is one feature of this work which in our opinion 

 gives it a special value to students, and that is an excel- 

 lent glossary of about 1000 words. The index is also 

 ample and carefully arranged. 



The present work of Professor Nicholson is the latest 

 and best Manual of Zoology, and we recomend it strongly 

 to those interested in such studies. 



Life on the Seashore, or Animals of our Coasts 

 and Bays, with illustrations and descriptions. By 

 James H. Emerton, author of Structure and 

 Habits of Spiders. Naturalists' Handy Series No. 1. 

 George A. Bates, Salem, Mass., 1880. 



This charming little work is the first of a series of 

 handy books suitable for amateur naturalists, a class 

 now happily on the increase. 



The author has provided a pleasant companion which 

 should be in the hands of ail visitors to our coasts, en- 

 suring a never failing fund of amusement, leading insensi- 

 bly to one of the most delightful of scientific stud es. 



Mr. Emerton states " I have tried to give such ex- 

 planations of some of our common animals of the New 

 England coast as have been otten asked for by persons 

 little acquainted with zoology, and to give such directions 

 about collecting and observing them as have been found 

 useful to students who come to the shore for a short 

 time in the summer to study animals that they before 

 knew only from pictures." 



The book is divided into four parts, treating separately 

 animals which are found " between the tides," " near low 

 water mark," " surface animals," "bottom animals." The 

 reader will find this an excellent arrangement. We 

 find above one hundred and fifty excellent wood cuts, 

 which faithfully represent the objects described in the 

 body of the book ; the sensational and misleading illus- 

 trations to be found in a somewhat similar work find no 

 place in this volume. We can therefore recommend Mr. 

 Emerton's work as not only a reliable guide, but one 

 which will create a healthful desire for knowledge in 

 those who are so fortunate as to possess it. 



CHEMICAL NOTES. 

 Contribution to a Knowledge of Saponification of 

 Fats. — The name fat is generally applied to a mixture of 

 the tri glycerides of palmitic, stearic, and oleic acids. As 

 regards the animal fats this assumption has been in all 

 cases verified, but the vegetable fats display certain not un 

 important deviations. J. Konig, J. Kiesow, and B. Aron- 

 heim, in saponifying vegetable fats, obtained invariably 

 less glycerine than is required for forming the glycerine- 

 ethers of the fatty acids — a fact pointing to the conclusion 

 that free fatty acids must be present, since the quantity of 

 cholesterine occurring in the plants is too small to com- 

 bine with the fatty acids. For saponification, potassium 

 and sodium hydrate were used along with the other basic 

 oxides, the latter substances being considered equal in 

 value to the former, the only difference being that the pro- 

 ducts in the one case are termed " soaps," and in the other 

 " plasters." It was assumed hitherto that the tri-glycerides, 

 like other ethers, were completely decomposed by the 

 above named ethers into salts of the fatty acids and glyce- 

 rine, and that equal quantities of glycerine were obtained 

 in all cases. For the sapor ification of fats and the separa- 

 tion of the products, J. Konig had proposed a process 

 which consists essentially in treating the fat operated upon 

 with an excess of lead oxide in presence of water at 90 to 

 ioo°. Dr. von der Becke, when attempting at his request 

 to saponify cacao-butter in this manner — in order to dis- 

 cover a process for detecting the sophistications of this pro- 

 duct — found that it could not be saponified with lead oxide, 

 at least not in this manner. It was found on further expe- 

 rimentation that the quantity of glycerine obtained on sa 

 ponification with potassium hydrate was in all cases con- 

 siderably the highest. In the easily saponifiable fats, but- 

 ter, lard, and olive oil, the difference was found less 

 manifest, but it was much more distinct in those which are 

 hard to saponify. Cacao-butter and tallow, if saponified 

 with lead oxide, yield scarcely traces of glycerine. A mix- 

 ture of an easily saponifiable fat like butter with cacao- 

 butter gave the same quantity of glycerine as if butter alone 

 were employed. It is possible that the reaction when once 

 set up may extend itself. Hence it appears that in the 

 case of some fats the method of saponification with oxide 

 is not trustworthy, and that when the accurate determina- 

 tion of the proportion of glycerine in a fat is required, the 

 saponification must be effected with potassium hydrate. 



Contributions to the Characteristics of the Alka- 

 line Earths and of Zinc Oxide. — The alkaline earths and 

 zinc oxide if their hydrates, carbonates, and nitrates are 

 heated to complete decomposition, are obtained in the fol- 

 lowing specific gravities. Lime is obtained amorphous 

 from the hydrate and carbonate, but in regular cubic crys- 

 tals from the nitrate ; in either case of the sp. gr. 3.25. 

 Strontia is obtained from the hydrate and carbonate amor- 

 phous, and of sp. gr. 4.5, but from the nitrate in regular 

 crystals and of sp. gr. 4.75. Baryta is obtained from the 

 1 ydrate in optically one- or two-axial crystals, of sp. gr. 

 5.32 : but from the nitrate in regularly cubic crystals of sp. 

 gr. 5.72. Magnesia is always obtained in the amorphous 

 form of sp. gr. 3.42. Zinc oxide is obtained amorphous 

 from the hydrate and carbonate of sp. gr. 3.47, but from 

 the nitrate in hexagonal pyramids of sp. gr. 5.78. 



Prof. Pritchett, of the Morrison Observatory, Glasgow, 

 Mo., has made arrangements to drop a Time-Ball at 

 Kansas City. 



Determination of Silicon in Iron and Steel. — One 

 grm. iron or steel is placed in a porcelain crucible with 

 25 c.c. nitric acid of 1.2 sp. gr. When the reaction is over 

 25 to 30 c.c. dilute sulphuric acid — I part acid and 3 water 

 are added, and the solution is heated till the nitric acid is 

 entirely or nearly expelled. When the residue is suffi- 

 ciently cool water is cautiously added, and the contents of 

 the capsule are heated till the crystals are perfectly dis- 

 solved. The solution is then filtered as hot as possible, 

 and the residue washed first with hot water, then with 25 to 

 30 c.c. hydrochloric acid of sp. gr. 1.20, and finally again 

 with hot water. After drying and ignition the silica is ob- 

 tained snow-white and granular. — T. M. Brown. 



