ON LARD, AND COMPOUNDS MADE WITH IT. I ^5 



water was so interposed, that it was difficult to separate the 

 whole of it. The water acquired a yellow colour, and a 

 slii^Htly bitter taste; was scarcely at all acid; aud did not 

 coutaiii an atom of mercviry. 



By wny of comparison some ointment only a day old was 

 treated with hot water as loni* as it would take up any thing. 

 This had nearly the same clinvacters as the water with which 

 the old ointment was washed, and scarcely exhibited any 

 traces of mercury on the addition of a hidrosulphuret. 



Henco ii was natural to conclude, that the acid nitrate of The acid con. 

 mercury had undergone a change; aud it might be P^^" curv to vdlow 

 8umed, that it had passed to the state of yellow nitrate, or nitrate. 

 nitrous turbith, which is little soluble in water. On keep- 

 ing the ointment a long time in fusion, liowever, no turbith 

 separated f o n it, so that it must be intimately united or 

 dissolved in the la^-d. To satisfy himself of the possibility Oxlgenized 

 of this solution, Mr. Vogel heated turbith with oxigenized la'dandydlow 

 Jard; and having decanted the clear fluid part, it perfectly form unguen- 

 resembled the unguentum citriuum, and contained a large turn citrmuro. 

 quantity of mercury. 



With respect to the virtues of this ointment, which some Some consider 



physiciansi assert are the same with those of lard simply oxi- the mercury as 

 . ... ... useless. 



genized by nitric acid, I do not pretend to decide : but it is 



probable, that a substance containing mercury in actual 



combination must produce different effects from one that 



does ijot. 



Instead of the acid nitmte employed above, Mr. Vogel Neutral nitrate 



next took neutral nitrate at a minimum, reduced it to a fine ^^'^"ffs^ from 



■ white to vel- 



powder, and projected it into heated lard. Bubliles were low by lard; 



immediately produced, and the white powder of the nitrate 



was soon changed to a yellow. The lard acquired a solid 



consistence, and contained mercury in solution. 



The neutral nitrate then is decomposed by lard : not that which takes up 

 the mercur>' parts with oxigen to it, for it is already at a mi- part of its acid. 

 nimufii ; but the nitric acid quits in part the oxide of mer- 

 cury, and attacks the lard, by which it is decomposed ; the 

 result of which is yellow nitrate of mercury, whjch in fact 

 contains but little nitric acid. 



With the njtrates of silver and lead, and the oximuriates Other mct»lli« 

 of platina and mercury, very little decompositioi^ takes place, **^^*' 



Yoi^-XVlU-OwT. I8O7. . I ' and 



