58 
POPULAR SCIENCE REVIEW. 
the effort to compare so fatiguing, that probably very few 
persons have made the attempt. That the juries themselves did 
not examine too closely seems likely, from the profusion ol 
medals, and “ honourable mentions,” distributed without much 
judgment, and often entirely without or against reason. 
While, however, we believe, that in the state presented to 
the public, the Exhibition in this department is not what it 
ought to have been, we are satisfied that an orderly grouping 
of similar objects from different countries, for the purposes of 
comparison, would be productive of great good. It is not easy 
to say how far this is practicable generally. It may not be 
desirable in manufactures, which of themselves are definite 
objects of interest. But in the case of raw material, there 
seems httle reason to doubt that order might be attained, and 
no doubt whatever that it is in every sense desirable and abso- 
lutely essential to ensure a proper use being made of the 
opportunity offered. 
No. III. 
CHEMICAL PRODUCTS.— THE APPLICATION OF 
WASTE. 
BY WILLIAM CROOKES, P.C.S., EDITOR OP THE “ CHEMICAL NEWS.” 
T HE progress of our great chemical manufactures during 
the last ten years, as exemplified in the International Ex- 
hibition of 1862, appears chiefly to have been directed towards 
the utilisation of waste substances. The casual visitor to the 
Exhibition, wandering through the.Eastern Annexe, and noticing 
the grand scale and great importance of some of the manufac- 
tures there illustrated ; the gorgeous colouring matters exhibited 
by Messrs. Perkin and Son; and Simpson, Maule, and Nicholson; 
the stupendous blocks of alum ; the beautiful yellow and red 
crystalline masses of ferro- and ferri-cyanide of potassium ; the 
enormous cakes of paraffin, a chemical curiosity in 1851, one of 
the largest chemical manufactures in the world in 1862; and, 
knowing the incalculable boons which science has bestowed 
upon our national wealth and the world’s civilisation by the 
introduction of the lucifer match, and development of the phos- 
phorus manufacture, artificial manure, paper, &c., — the visitor 
would be little prepared to hear that most, if not all, these im- 
