30 THE BEGINNINGS OF LIFE. 



for physiology, viz., the formation of albuminates in 

 plants, respecting which we are in possession of scarcely 

 anything beyond conjecture; hitherto this has been 

 regarded as one of the greatest mysteries of organic 



nature If yeast cells, placed in a mixture of 



ammonia, tartaric acid, sugar, and phosphate, could 

 propagate and multiply, it is evident that an albuminate 

 must have been formed from the elements of this 

 mixture, since one of the chief constituents of the yeast 

 fungus is an albumenoid substance ^.' 



All that is here said by Liebig becomes even still 

 more striking after my own observations, as to the 

 freedom with which Bacteria and Torule multiply not 

 only in solutions of ammonic tartrate to which a 

 phosphate has been added, but also in solutions of 

 tartrate of ammonia alone. The fact that this occurs 

 shows that these simple saline substances not only con- 

 tain the elements necessary for the formation of living 

 matter, but that the passage must be comparatively easy 

 from the saline mode of collocation of the elements 



^ Although quite willing to believe that this may take place, Liebig 

 contends that Pasteur has not proved that it does occur. Some of 

 Liebig's objections are, however, we think, based upon possible mis- 

 conceptions. Actual beer-yeast contains sulphur as a constituent, an 

 element which was not known to exist in Pasteur's mixture. It seems 

 quite possible, however, that TorulcB closely resembling beer-yeast in 

 appearance may exist, into whose composition sulphur does not enter. 

 The freedom with vhich Bacteria and Torulce develop in a simple 

 solution of tartrate of ammonia in distilled water make it doubtful 

 whether the presence even of phosphorus is absolutely necessary for the 

 formation of the simplest kinds of protoplasm. 



