Juke 17, 1910] 



SCIENCE 



951 



in Nature suggested that there might be some 

 difficulty in understanding how a certain rate 

 of cliange of momentum could produce unit 

 change of momentum per second. It was also 

 suggested that, while we might measure the 

 hunger of a man under various circumstances, 

 by determining the number of pounds of beef 

 he would consume, we should hardly be war- 

 ranted in saying that hunger " is " a certain 

 number of pounds of beef. 



We shall probably continue to measure 

 forces with spring balances. We shall al- 

 ways find that the force applied to a loaded 

 wagon is greater than the change per second 

 in its momentum. Tait's definition might 

 give a zero value when the spring balance 

 might show that the horse was behaving in a 

 very creditable way. 



Francis E. JSTipher 



SCIENTIFIC BOOKS 

 The Wonders of Animal Ingenuity. By H. 

 CouPiN, D.Sc, and John Lea, M.A., au- 

 thor of " The Romance of Bird Life." 

 Philadelphia, J. B. Lippincott Company. 

 1910. Pp. 163. 



This is an American reprint of an English 

 book of popular natural history for young 

 people, dealing with the " wonders " of the 

 nest-building instinct in spiders, insects, 

 fishes, birds and mammals. The facts are 

 gathered largely from such authorities as 

 Huber, Moggridge, Fabre and Brehm. They 

 are treated entirely from the traditional point 

 of view with regard to instinct, and despite a 

 w^arning in the preface against attributing 

 ■" human motives and reason where they have 

 no existence," the " little architects " are 

 more or less humanized throughout. It 

 ■would seem that a no less popularly interest- 

 ing book could now be written from the more 

 modern point of view, dwelling on the fail- 

 ures and variability of instinct. However, 

 for young English readers the book would no 

 doubt accomplish the purpose set forth in the 

 preface, of aiding " towards a greater love of 

 animals and a desire to observe and under- 

 ■stand their ways." But for the American 

 ^Nature, XVI., 182, 227. 



reader its value is lessened by the fact that 

 so few of the species whose behavior is de- 

 scribed are natives of this country. This is 

 especially true in the case of the birds : for 

 instance, when the ovenbird is mentioned it 

 is the South American Furnarius rufus that 

 is meant, instead of our owa little warbler, 

 the discovery of whose nest is a pleasant 

 achievement for any amateur naturalist. 



Margaret Floy Washburn 



Linseed Oil and other Seed Oils. An Indus-; 

 trial Manual. By William D. Ennis, M.E., 

 Professor of Mechanical Engineering in the 

 Polytechnic Institute of Brooklyn. 8vo, 

 cloth, pp. 316. Price $4.00 net. New York, 

 D. Van Nostrand Co. 1909. 

 This deals minutely with the production of 

 linseed and other expressed oils, particularly 

 cottonseed, sunflower, peanut and rape. A 

 glance at the table of contents shows the wide 

 scope of the book : this is as follows : Intro- 

 ductory, The Handling of Seed and the Dis- 

 position of Its Impurities; Grinding; Tem- 

 pering the Ground Seed and Molding the 

 Press Cake; Pressing and Trimming the 

 Cakes; Hydraulic Operative Equipment; The 

 Treatment of the Oil from the Press to the 

 Consumer; Preparation of the Cake for the 

 Market; Oil Yield and Output; Shrinkage in 

 Production; Cost of Production; Operation 

 and Equipment of Typical Mills ; Other Meth- 

 ods of Manufacturing; The Seed Crop; The 

 Seed Trade; Chemical Characteristics of Lin- 

 seed Oil; Boiled Oil; Refined and Special 

 Oils; The Linseed Oil Market; The Feeding 

 of Oil Cake; Miscellaneous Seed Oils;' The 

 Cottonseed Industry. 



The chapters on boiled and refined and 

 special oils and the oil market are particu- 

 larly instructive and valuable. Another 

 chapter deals with the chemical testing of the 

 oil, many of the methods being taken from the 

 bulletins of the U. S. Department of Agri- 

 culture, Division of Chemistry. The method 

 for the execution of the Maumene test can not 

 be recommended. It is an open question as to 

 whether chemical tests should be included in 

 a manual of this kind. 



