June 23, 1910] 



NATURE 



48: 



\\>\\. and this no doubt detracts somewhat from its 

 value to the English manufacturer. On the other 

 hand, the latter will probably find some compensation 

 in seeing how his problems are regarded by other 

 eyes. 



After a short historical description, the first eight 

 I'n.tpters deal with the standard forms of equipment 

 d in extracting oil from seed bv the pressure pro- 

 L ■^s. Such matters as the location and planning of 

 the mill, the selection of the best type of apparatus, 

 the handling of the seed, the treatment of the oil, 

 and the moulding of the oil-cake are discussed in 

 ample detail. Economical production is kept in view- 

 throughout. 



In the second and some later chapters we come 

 across pages of algebraical formulae which at first 

 si;_:ht look like extracts from a mathematical text- 

 ' ' 'k. They are the author's method of analysing in 

 leral terms various problems of manufacture, in 

 i ) der to show definitely the effect of adopting certain 

 processes or courses of treatment. For example, the 

 question is discussed algebraically whether in given 

 cu cumstances it pays best to separate the " screen- 

 ings" from the seed and sell them, or to pass them 

 through the mill with the seed, or, thirdly, to separate 

 them and grind them up with "cake." When all 

 the factors have been combined into a formula, the 

 man with an eye for an equation can readily see 

 what effect an alteration in any factor will tend to 

 produce. The man not endowed with such an eye 

 can readily puzzle the matter out, and be all the 

 better for the exercise. In such a way an intelligent 

 control over the operations can be maintained. 

 . In the subsequent chapters the method of extract- 

 ing oil from seeds by percolation with a volatile 

 solvent is described and discussed. Only about lo 

 per cent., however, of the oil produced in the United 

 States is obtained in this manner. 

 . Questions of output, shrinkage, and cost of pro- 

 duction are dealt with at some length ; and there are 

 chapters on refining, on boiled oil, and on miscel- 

 laneous seed oils. The author contrasts the great 

 development of the cottonseed oil industry in the 

 United States with the comparative neglect shown in 

 regard to other oils — linseed excepted. Rapeseed oil 

 is the most conspicuous failure ; but more olive oil 

 should be produced, he thinks, in California, more 

 cocoa-nut oil on the Pacific coast, and more pea-nut 

 oil in the eastern States. 



A section on the chemical characteristics of linseed 

 oil gives briefly the chief items which the oil-works 

 chemist requires to know. Information on various 

 technical points, collected from scattered trade 

 journals, has also been included, and certain official 

 rules and regulations, such as those of the New York 

 Produce Exchange and the Minnesota Grain Com- 

 mission, have been laid under contribution in respect 

 of the commercial aspects of the industry. 



Many illustrations of apparatus are given, and the 

 treatment is throughout of eminently practical char- 

 acter. Probably there are few intelligent oil manu- 

 facturers who would not be able to get at least some 

 useful hints from the book. C. S. 



NO. 2 12 I, VOL. 83] 



ZOOLOGY OF THE INDIAN OCEAN. 

 An Account of the Alcyonarians collected by the Royal 

 Indian Marine Survey Ship "' Investigator " in the 

 Indian Ocean. By Prof. J. Arthur Thomson and 

 J. J. Simpson. Part ii.. The Alcyonarians of the 

 Littoral Area. With a Report on the Species of 

 Dendronephthya by Dr. W. D. Henderson. Pp. 

 xviii + 319 + ix plates. (Calcutta: Indian Museum, 

 1909.) 



THE first part of the memoir of the Alcyonarians of 

 the Indian Ocean was published in 1906, and re- 

 viewed in Nature of May 2, 1907. The second part 

 deals with the shallow-water species, and fully main- 

 tains the high standard set by the first in wealth of 

 detail and sumptuous illustration. 



The authors of this volume have set themselves a 

 task which is far more difBcult than that of naming 

 and describing the deep-sea species, and they have 

 faced it boldly and, on the whole, satisfactorily. In 

 the order Alcyonaria there are certain genera of 

 wide distribution in tropical shallow waters which 

 exhibit an infinite variety of form, of mode of branch- 

 ing, of colour, and of detail in skeletal characters, and 

 the zoologist to whom the task is assigned of naming 

 the spirit specimens sent to him by the collectors has 

 to form an opinion as best he can on the vexed ques- 

 tion of what characters or groups of characters in 

 combination are sufficiently important to constitute a 

 specific difference. In the absence of any knowledge 

 of the development of the colonies, or of the relation 

 of the different forms of growth to their surroundings 

 on the reef, or of the transmission by heredity of the 

 different characters he uses for purposes of classifica- 

 tion, his opinion is rarely one of very great scientific 

 value. Nevertheless, if his task is conscientiously per- 

 formed, his descriptions accurate, and his illustrations 

 adequate, our science is enriched by a number of 

 recorded facts which may be of considerable value 

 when the solution of the underlying biological 

 problems is seriously taken in hand. 



No better illustration of this difficulty could be 

 found than that of the genus Spongodes, so excel- 

 lentlv treated in this volume by Dr. W. D. Henderson. 

 Following the example of Prof. Kiikenthal, in whose 

 laboratorv he worked for some months, Dr. Hender- 

 son has distributed the specimens in the collection 

 among no fewer than sixty-one species, of which fifty- 

 three are described as new to science. But the 

 question must occur to anyone who has seen 

 Spongodes in abundance in its natural surroundings 

 whether these numerous species could be maintained, 

 even by the author himself, if another consignment 

 of the same or greater dimensions were sent to him 

 from the same locality. There is an advantage and 

 a disadvantage in creating a large number of specific 

 names for a common genus like Spongodes. If 

 enlarges our knowledge by giving us detailed descrip- 

 tions and illustrations, and in so far as it does that 

 it is a gain ; but, on the other hand, it tends to 

 underestimate the importance of what may be a very 

 definite character of all these common shallow-water 

 genera, the power of adaptability to their immediate 



