OBSERVATIONS ON MURIATIC ACID. 



233 



CALOMEL. 

 The oxide of mercury in calo- 

 mel is compofed of, 

 Mercury - - 89,3 



Oxigen - - ^10,7 



100,0. 

 And calomel is compofed of, 



Mercury79 C oxide of 1 „„ , 

 Oxigen 9,5 \ mercury j * 

 Muriatic acid - 1 1 ,5 



100,0. 



CORROSIVE SUBLIMATE. Comparative 

 The oxide of mercury incorro- ft^ement. 



five fublimate is compofed of, 

 Mercury - * 85 



Oxigen - - - 15 



100. 

 And corrofive fublimate is com- 

 pofed of, 

 Mercury69,7 j" oxide of") g2 

 Oxigen 12,3 \ mercury j 



Muriatic acid - 1 8 



100. 



Thefe proportions are different from thofe given by Lemerv, 

 GeofFroy, Bergman, &c. But, without calling in queftion 

 the accuracy and ikill of thefe chemiits, it is fair to aifei t, 

 that the pure materials ufed by modern chemifts, are more 

 likely to lead to fure refults, than the impure re-agents of the 

 ancients. 



In thefe falts we find another inftance, that, in proportion as The moftoxig. 



metallic oxides contain a greater quantity of oxigen, thev re - °* 1( j esfaturate 

 • . & . . l • • • i theJar g ei * quart- 



quire a greater quantity of acid to enter into combination with tity of acid. 



them. • 



The method I have followed, to afcertain.the proportions obfervations t» 

 juft Hated, may appear, at firft view, not to be the fhorteft that * hcw ** the 

 I might have adopted. But I have tried others, and I have a ^cs were found 

 found none fo accurate. It is impoffible, fynthetically, to -he ™<>ft »ccu- 

 convert a given quantity of mercury into calomel, in fuch a rae an C0nci e * 

 manner as to be certain that none of it is in a different ftate 

 from that required. And, if we would attack calomel analy- 

 tically, the action of the alkalies, without which we cannot 

 proceed, is fuch as to alter the nature of the oxides. I have 

 alfo made many comparative experiments, by dhTolving calo- 

 mel in nitro-muriatic acid, {which converted it into corrofive 

 fublimate,) and then precipitating by ammonia ; but I have 

 not found thefe trials fo fuccefsful as thofe I have defcribed. 

 The nature of the precipitate from corrofive fublimate by am- 

 monia, certainly differs, according to the excefs of a©id that 

 may be prefent; and mercury feems to have the power of ex- 

 iting in many degrees of combination with oxigen. The only 

 3 precaution 



