322 Of the Progress of the spontaneous Mixture 



changed in appearance by the end of two or three 

 days ; from being transparent, they became semi-opaque 

 and of a whitish color ; they changed at the same time 

 with regard to their specific gravity as well, and became 

 a little lighter. These changes were evidently due to 

 the beginning of saponification. 



This accidental circumstance made it necessary for 

 me to renew each day the drop of oil which served as 

 the index, allowing the others to pursue their way to 

 the surface of the liquid without paying any further 

 attention to them. 



By using as indices little glass balloons of proper 

 size and thickness, instead of the drops of oil, the 

 inconveniences arising from the saponification of the 

 oil might be avoided. 



But without spending more time on the details of 

 these experiments, I hasten to return to their results. 

 They showed that the mixture went on continually, but 

 very slowly, between the various aqueous solutions 

 employed and the distilled water resting upon them. 



There is nothing in this result to excite the surprise 

 of any one, especially of chemists, unless it is the ex- 

 treme slowness of the progress of the mixture in ques- 

 tion. The fact, however, gives occasion for an inquiry 

 of the greatest importance, which is far from being easy 

 to solve. 



Does this mixture depend upon a peculiar force of 

 attraction different from the attraction of universal 

 gravitation, a force which has been designated by the 

 name of chemical affinity ? Or is it simply a result of 

 motions in the liquids in contact, caused by changes 

 in their temperatures ? Or is it, perhaps, the result of 

 a peculiar and continual motion common to all liquids, 



