REVIEWS i7S 



products ; a revised edition was thus definitely wanted. The scope of the 

 work has been reduced by restricting attention to the products of present or 

 prospective importance in Indian commerce or industry. 



The arrangement of the contents is alphabetical ; vegetable products are placed 

 generally under the scientific name of the plant whence they are derived, whilst 

 animal and mineral products appear more commonly under their ordinary 

 designations. The convenience of the reader unacquainted with botanical nomen- 

 clature is studied, and by reference to the index or to collective articles, such 

 as Oils, he can usually find with ease the account of products in which he is 

 interested. This cross-referencing has not been carried out with absolute uni- 

 formity, and we have not been able to ascertain how any one quite ignorant of the 

 subject could find, for example, which were the chief tanning substances produced 

 in India. 



The general treatment is very full, and many of the more important articles are 

 practically monographs. The account of cotton (pp. 569-624) affords a good 

 example. A general introduction is followed by a discussion of the history of 

 cotton from very early times, not only in India but also in other countries. This 

 is very interesting, but in a commercial book of reference might well, perhaps, have 

 been abridged. Some fourteen pages are next devoted to the botany of the 

 cottons, in which the author summarises the views recently expounded in detail in 

 his Wild a?id Cultivated Cotton Plants of the World. Adulteration and deteriora- 

 tion and improvement of stock are followed by a very good account of cultivation — 

 area, seasons, yields, etc. — in the chief Indian districts. This part has been very 

 systematically compiled, and it is possible to work through it and ascertain for 

 example the relative importance of each district, times of sowing and picking, and 

 other important facts. Short sections on soils, manures, diseases and pests, 

 ginning and baling, cotton seed and the fibre follow, and the article concludes 

 with a lengthy section on Indian trade and manufactures, whilst copious references 

 to literature are given throughout. 



It is thus evident that the treatment is comprehensive and by no means 

 confined purely to Indian interests. The work might perhaps have been im- 

 proved in some ways had the scope been more restricted. Thus, wishing to 

 ascertain the chief commercial varieties of Indian cottons and their relative 

 values, we were unable to find any concise statement to this effect, and had to 

 obtain the information elsewhere. Yet this is precisely the book in which it 

 should have been given. 



Similar criticisms might be advanced regarding some of the other articles. 

 They do not, however, detract seriously from the great service which Sir George 

 Watt and his coadjutors have rendered in bringing together this mass of infor- 

 mation regarding the products of the Indian Empire. As we hare already 

 indicated, we are of opinion that its scope might in some instances have been still 

 further restricted ; but, on the other hand, this wider range will tend to enhance 

 the value of the book to planters and others interested in commercial products in 

 other parts of the world than India. 



W. G. Freeman. 



Recent Publications of Messrs. Zeiss & Co. 



MESSRS. Zeiss & Co. have recently issued a number of prospectuses describing 

 the apparatus necessary for the projection of various optical phenomena. Among 

 these are three describing (1) a collective-lens system of great light-gathering 

 power (Mikro 233), (2) apparatus for the projection of experiments on polarised 



