THE LIFE OF MATTER. 425 



reproduce itself. There is, then, in this tin entirely new condition 

 peculiiir to the organized being-^ a property well adapted, it would 

 seem — and this time without any possible doubt — for separating liv- 

 ing matter from brute matter. It is not so. 



It would not be impossible to imagine a system of chemical bodies 

 organized like the animal or vegetable economy, so that a destruction 

 would be compensated for by a growth. What is imi)ossible is to 

 realize the supposition of M. le Dantec, a desti'uction that would at 

 the same time be an analysis. And an additional perplexity occurs 

 when he supposes that in the successive acts that have taken place 

 exchanges of material may occur. 



There is no necessity for making this impossible chemistry a char- 

 acteristic of the living being. The chemistry of the living being is 

 general chemistry. Berthelot repeated this after Lavoisier. These 

 teachings of the masters should not l)e lost sight of by us. 



Let us return to generation, properly so called, and tind there the 

 characteristics of brute bodies — of crystals. 



Tlie Hoiving of 'micro-organisms. — When a micro-biologist wishes to 

 ])ropagate a species of micro-organisms he charges a culture medium 

 with a siuall number of individuals (one is all that is actually neces- 

 sary) and soon o})sei'ves their rapid multiplication. Usually, if only 

 ordinary microbes that exist in atmospheric dust are wanted, the oper- 

 ator is not o))ligcd to take the trouble of charging the culture; it' the 

 cultui'e tul)e remains open and the medium is suitably choscMi, some 

 germ of a common species will fall in and the licjuid will become col- 

 onized. This has the appearance of a spontaneous generation. 



The sowing of cnjxUtls. — Concentrated solutions of various sub- 

 stances, supersaturated solutions of sulphate of soda, sulphate of 

 magnesia, and chlorate of soda are also wonderful culture media for 

 certain mineral organic units — certain crystalline germs. Ch. Dufour, 

 expin'imenting with water cooled below ' C, its point of solidihca- 

 tion, Ostwald, with salol kept below 39.5^, its point of fusion, Tam- 

 mann. with betol, which melts at IHi , and, before them, (xernez, with 

 melted phosphorus and sulphur — all these pli3\sicists have shown that 

 liquids in surfusion are also media specially appropriate for the cul- 

 ture and propagation of certain kinds of crystalline individuals. 



Some of these facts have become classic. Lowitz showed in 1785 

 that a scjiution of sulphate of soda could be concentrated by evapora- 

 tion so as to contain more salt than was conformable with the temper- 

 ature, yet without depositing the excess. If, however, a solid 

 fragment, a crystal of salt, Avas thrown into the liquor, that excess 

 would soon pass into the state of a crystallized mass. The first crys- 

 tal engendered a second similar to itself; the latter engendered a 

 third, and so on from one to the other. If we compare this phenom- 

 enon with that of the rapid multiplication of a speci(\s of microbes in 



