with the Oxides of Lead and the Alkalis, 43 



natioa of the oil with the oxide of lead ? And upon the ex- 

 periments which these inquiries would produce, might we 

 i)ot establish the theory of one of the most important opera- 

 . tions of pharmacy, and the relations which its results must 

 have with the alkaline soaps ? 



Such are the considerations which led me to the follow- 

 mg experiments : 



I placed in a tubulated bell glass equal parts of olive oil,- 

 litharge, and water: I adapted to the orifice of the bell oj^ss 

 a tube inserted into lime water, with a bladder at the orifice 

 to prevent the access of the external air ; this bladder was 

 so disposed that I could move a spatula in the interior of the 

 bell glass, in order to keep the matter from sticking to the 

 bottom of the vessel. The mixture having been brought to 

 the boiling point, I saw the oxide of lead successively pass 

 from red to yellow, and from yellow to white. During the 

 time the experiment lasted carbonic acid was almost always 

 liberated. I allowed the apparatus to cool, in order to exa- 

 U)ine successively the results of this experiment. 



The water which had served as the intermedium had a 

 strong metallic taste. When placed in contact with yeast 

 at ihe necessary temperature, I was never able to produce 

 fermentation*. It precipitated evidently by the sulphuric 

 acid and the hydrogen-ited sulphurets f. I passed sulphu- 

 retted hydrogen into it, until no more precipitate was 

 formed; and I filtrated it in order to separate the sulphuret 

 of lead. 



The filtered liquor had also a very strong saccharine taste; 

 it was evaporated to the consistence of a syrup -, the acetate 

 of lead at this moment did not demonstrate the presence of 

 sulphuretted hydrogen. My attempts to ferment it were 

 equally fruitless as before the separation of the oxide of lead ; 

 exposed to the air, it strongly attracts its humidity ; when 



f \ was for a moment led into an errqr, because I had inadvertently used 

 yeast, which still contained some alcohol, not having been properly washed. 



•f 1 was convinced by various experiments that it was of no importance 

 whether in tha solution of the oxide of lead the fats or oils were rancid or 

 not, although Scheele thinks they should be rancid. In fact, it v/ill be seen 

 in the course of this paper that this circumstance is completely foreign ro 

 the sqlutioii. 



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