~ 1822.] Philosophical Transactions for 1822, Part Il. 465 
Dr. Davy believes “ that changes very similar take place when 
corrosive sublimate is heated with other oils, both-volatile and 
fixed;” and states the experiments on which that belief is 
founded. 
He then says, “ In a paper published in the Philosophical 
Transactions for 1812, I have noticed the affinity of muriatic 
acid for corrosive sublimate. This solution may be considered 
as composed of 11 proportions of water, 1 muriatic acid,* and 
1salt. In the act of forming, heat is evolved. At 74° this 
solution is of specific gravity 2-412. When its temperature is 
lowered a few degrees, it suddenly becomes solid, and forms a 
mass of delicate needle crystals, which rapidly melt, when the 
containing vessel is held in the warm hand.” 
. Dr. Davy next adverts to the common statement in systema- 
tic works, that corrosive sublimate is soluble in the sulphuric and 
nitric acids, as well as in the muriatic acid. He shows from 
experiment that this 1s not the case ; and then proceeds to relate 
in the following terms some experiments which tend to corrobo- 
rate an opinion long ago entertained, that muriate of ammonia 
and corrosive sublimate are capable of uniting and of furming a 
double salt. , 
“In the dry way, there appears to be an affinity exercised 
between corrosive sublimate and muriate of ammonia. A mix- 
ture of the two, in the proportions of 34 of the former and 6°75 
by weight of the latter, heated, forms a compound more fusible 
and less volatile than either ingredient separate ; it may be kept 
liquid without volatilising by the gentle heat of a spirit lamp ; on 
cooling, it exhibits a very light-grey translucent mass of a faint 
pearly lustre; strongly heated, it sublimes, and appears to be 
partially decomposed, as traces of calomel and free muriatic acid. 
are found mixed with the sublimate. This compound, formed of 
one proportion of each ingredient, has more the character of a 
chemical compound, than any other mixture of the two ingre- 
dients that I have tried.” 
- “In the moist way, the affinities of corrosive sublimate and 
muriate of ammonia are better marked, and some of the combi- 
nations of the two have tolerably well-defined qualities. ‘The 
following have the best claim to be considered distinct combina- 
tions of any which I have yet made: 
No. Water. Muriate of ammonia. Corrosive sublimate. 
MA Maaig poy pie LU Saniaiece-cieree) O70 i 'eo\a wh ROL 
2, SSS, CE SI SRE Ae 7 Pea ee yl e' 
< Pe 10) ES aS 5 | A 
Ts ae nh 0 sserblnioty, LOSLEA chciclehde soe 
“ No. 1 is liquid at 140°; on cooling, it forms a solid mass of 
needle crystals. No. 2is liquid at 85°, and solid at 55°. Inthe 
* New System of Chem. Phil. by John Dalton, vol. ii, p. 295. 
New Series, vou. tv. 2H 
