June] REVIEWS AND NOTICES OF BOOKS. 227 



general history of Disinfection, from which it would appear 

 that during past years mankind has been struggling against filth 

 and disease, with various retrogressions, and with but partial 

 success — with no rational conception of the evil to be avoided, or 

 of the nature of the remedy to be sought. 



From the East, however, he traces practices of public cleanli- 

 ness, which were strictly adopted by the Romans, such as the 

 use of drainage, of disinfectants applied to sewers, and of the 

 daily removal of all refuse or decomposing animal matter from 

 the roads. Pitch, and the substances derived from its distillation, 

 appears to have been highly prized, and to the same products 

 modern science turns with the greatest confidence. 



The idea that epidemic disease was produced or encouraged by 

 the decay of animal or vegetable matters, was deeply rooted in the 

 minds of the ancient Greeks and Romans ; and after a general 

 laxity of such belief and carelessness of such consequence, modern 

 science reverts to this idea, assisted by the researches of Dusch, 

 Schroeder, Liebig and Pasteur. On this subject our author 

 says : — 



"The two great theories may be called Liebig's and Pasteur's 



the first, (Liebig's), dealing with organic decomposing matter 

 ready to communicate its action by its own activity. That idea 

 has a sound scientific basis, and I am disposed to think it quite 

 undeniable at present. 



" The second, that of Pasteur's, leads to organized bodies or 

 germs, and although he also has not originated the idea, its 

 clearest proof and expression is due to him. He does not seem to 

 have retained firm hold of a part of the battle ground gained from 

 chemistry. There is probably a point where the ' organic ' and 

 ' organised ' touch so nearly as to be difficult to distinguish but 

 here the distinction between the two is very real, and the point 

 of Contact is still to be sought." 



Cases of disease our author says are caused : — 



"1st. By gases. 



" 2nd. By vapours. 



" 3rd. By putrid or decomposing substances. 



"4th. By organized bodies in various stages and ferments.'' 



To meet these, disinfectants are employed of various natures 

 viz. : — 



1st. To attack the gases and vapours - Oxygen, chlorine. 



