557 



in this field." He must have overlooked some of the excellent 

 and inexpensive works on chemistry ; for example, " Modern 

 Chemistry," published in England (London 19U0), by William 

 Kamsay, D.Sc, Is. Such a book gives, in a very few pages, 

 almost all that is contained in Part I. of this work. 



The second part contains a general review of diffusion and 

 osmotic pressure in plants in their biological aspect, and will prove 

 a valuable addition to the library of the student of this subject. 

 The bibliography is full, and appears as footnotes to the various 

 pages. The raison cVetre of this portion is, to quote the author^ 

 " the presentation of the promising and unpromising points for 

 further research " ; and this is kept well in view, for the diffi- 

 culties are not passed over as though they were non-existent. 

 A concise account is given of what has been done, and of the 

 difficulties that still remain to be overcome. 



One naturally turns to the question of the ascent of the trans- 

 piration current in tall trees, the solution of which has baffled 

 so many investigators, and finds the author concluding that 

 "just how the sap is raised in trees is not known." The chapters 

 of this part are : Turgidity ; Absorption and Transmission of 

 Water ; Absorption and Transmission of Solutes ; and, The 

 Influence of the Osmotic Pressure of the Surrounding Medium 

 upon Organisms. 



The type is clear, and the binding good. A few uncorrected 

 errors, pp. 52, 72, and 93, suggest haste as the work passed 

 through the press. R. P- 



The Microscopical Examination of Foods and Drugs. By 



H. G. Greenish, F.I.O., F.L.S. 9| x G in., xxiv. + 321 



pages, 168 figures in the text. London, 1903 : J. & A. 

 Churchill. Price 10s. M. net. 



The appearance of this work by Professor Greenish will be very 

 welcome to analysts and others in this country who may be 

 called upon to examine powdered drugs and similar pharmaceutical 

 preparations, for, although much has been already written on the 

 subject, the information is so scattered through the pages of 

 scientific and technical journals that it is rarely available when 

 wanted. 



