xvi THE BEGINNINGS OF LIFE. 



found is that which I have named last — the neutral ammonia 

 tartrate. 



Several of these salts — the oxalate, the acetate, the carbo- 

 nate, and the tartrate of ammonia — contain within themselves 

 all the elements necessary for the building up of organic 

 substances. Nitrogen, carbon, hydrogen, and oxygen are 

 there, and they only require to fall or to be brought into 

 other modes of collocation in order to give birth to an 

 organizable compound. The crystals of the oxalate are very 

 small, those of the acetate are very deliquescent, and carbo- 

 nate of ammonia exists generally in the form of non-crystal- 

 line cakes i. The neutral tartrate, however, exists in the form 

 of tolerably large prismatic crystals, and it was within these 

 only that living matter and organisms were found. 



Before describing these organisms more particularly, it 

 will be well to glance for a moment at the origin or mode of 

 preparation of ammonic tartrate. The tartaric acid entering 

 into its composition is obtained from argol, the crude po- 

 tassic bitartrate derived from the grape. And although this 

 latter salt is derived from the tissues of a living plant, the 

 processes to which it is submitted, in order to obtain the 

 tartaric acid in an uncombined state, would most certainly 

 suffice to destroy all living ' germs ' which it might have con- 

 tained. After a solution of the potassic bitartrate has been 

 boiled for a time, calcic tartrate is gradually precipitated by 

 the addition of chalk and calcic chloride. The insoluble 

 calcic tartrate, after having been washed several times, is then 

 brought into contact with strong sulphuric acid, diluted with 

 only about four times its hulk of water, and this mixture is 

 boiled for half an hour ^. All this is necessary before a filtrate 



^ Obtained by a process of sublimation at high temperatures. 



^ The boiling point of such a solution would be several degrees above 

 ioo° C. Heat and acid combined, exercise a most powerfully destructive 

 influence upon organic matter, though even very dilute sulphuric acid, 



