177 



Sulphuric, then Hydrochloric and Sulphurous acids in order, 

 the action of the two latter being much more distinctly 

 marked than the action of the former. 



In making observations on the amount of free acid 

 required to prevent origination of life it is found that the 

 order of acid is the same as above, but that the line is much 

 more sharply drawn. 



TABLE IV. 



Experiments on the amourd of Free Acid contained in Water in loTiich Animal 



Life can originate. 



SULPHURIC ACID ADDED. 



TABLE V. 



HYDROCHLORIC ACID ADDED. 



Water acidified with 0-0025 grms. Sulphurous acid per 

 litre was allowed to stand exactly under the same conditions 

 as the former to see if life could originate in water contain- 

 ing that amount of acidity, but after standing twenty-one 

 days no life Avas visible. 



