INFUSORIA AND OTHEE ANIMALCULE. 241 



have been produced.* I myself have shown recently 

 how mineral matter can be converted by chemical 

 means into organic matter, and how this organic 

 matter, in the origin, must have been converted 

 into organized cells.f 



" In vain," says Bory de St. Vincent, and his 

 words coincide remarkably with our modern re- 

 searches, " in vain has matter been considered as 

 eminently brute [without life] . Many observations 

 prove that if it is not all active by its very nature, 

 a part of it is essentially so, and the presence of 

 this, operating according to certain laws, is able to 

 produce life in an agglomeration of the molecules ; 

 and since these laws will always be imperfectly 

 known, it will at least be rash to maintain that an 

 infinite intelligence did not impose them, since they 

 are manifested by their results." 



But we must quit these philosophical considera- 

 tions, as our work is purely of a practical nature. 

 Let us see then, first, what Infusoria are, and how 

 they are useful to man. 



The most simple and commonest form of in- 

 fusorial life is the Monad. .This animalcule, of 

 which there are several kinds, consists of a fine 

 pellucid membrane ; it forms a very minute sphere 



* Darwin " On the Origin of Species by Natural Selection," 

 London, 1860. 



t Phipson " Protoctista," etc., in the " Journ. de Medicine," 

 Bruxelles, Dec. 1861. 



E 



