234 NATURAL SCIENCE. ■ March, 1893. 



tively, the French are next with onl}^ -9 ; then the American with -6 ; 

 the Dane with -2 ; and other European nations with a rapidly- 

 decreasing amount down to the Itahan, who is presumably satisfied 

 with -ooi. 



The book is divided into three parts; the first, dealing with 

 " Botany and Culture," begins with a botanical description including 

 a good iigure of a shoot, and also sketches of the leaf and parts of the 

 flower. Chapter 11. tells of a few unproductive attempts at European 

 cultivation, and gives a very brief account of the culture and the three 

 yearly pickings in China. Then the preparation of green and black tea 

 is. described, the difference lying in the treatment of the leaves; the 

 author expresses his belief in the view that the black owes its colour to 

 the fermentation the leaves have undergone, to which is also due the 

 much greater percentage of ammonia salts than in the green, the pro- 

 portion being as 40 to 13. Anyhow, as we read in chapter IV., tea is a 

 delicious beverage, though liable to be spoilt in the making ; accordingly 

 we are told how they make it in China. Jide General Tcheng-Ki-Tong. In 

 Japan they do it a little differently, and in France differently again ; 

 the English method, which strikes us as infinitely superior to them all, is 

 not given. 



The physiological action includes not only the well-known effect 

 on the nervous system, but also that on the circulation and 

 respiration. 



The second part gives a useful account of its adulteration with 

 leaves from other plants. Rough figures of transverse sections 

 illustrate how by presence or absence of certain tissue elements and 

 arrangements we can distinguish the true from the false. 



Part 111. is chemical ; it tells us what tea contains, and how the 

 green and black varieties differ. The latter are usually much richer 

 in the characteristic alkaloid caffein or thein, which M. Bietrie decides 

 to consider as identical ; several of the methods of estimating the 

 alkaloid are described. The last part contains short diagnoses, so to 

 speak, of a large number of " teas," with hints for distinguishing 

 them by physical characters. 



We quite enjoyed reading the book, though it has the French 

 failing of falling to pieces as soon as opened. 



Messrs. Baillie re & Sons, of Paris, have just issued a new catalogue 

 of zoological works, referring especially to fishes (and fisheries), 

 reptiles, and batrachians ; also a useful catalogue of phanerogamic 

 botany. 



We gladly welcome the second volume of Mr. Blake's Annals of British 

 Geologv, containing abstracts of the books and papers published during 

 1 89 1. The editor's comments, which were not always gratefully 

 received, are now relegated to footnotes. The abstracts are generally 

 well done, but it seems a pity that so much space is occupied by lists 

 of names taken from British Museum catalogues. 



