270 Mr. R. Phillips on. the [Ocr. 
carbonaceous matter, and subjected it to a red heat; when cool, 
I found that it was readily dissolved by muriatic acid without 
the assistance of heat, and that Water threw down a copious 
white precipitate, which was evidently subtiuriate of protoxide 
of antimony. After filtration, I added ammonia to'the solution, 
but it occasioned the precipitation of a little peroxide of:iron 
only. It appears then the residuum was merely oxide of anti- 
mony in the highest state of oxidation ; for if it had contained 
any phosphate of lime in combination, it would have been dis- 
solved with the protoxide of antimony, and precipitated by 
ammonia after the separation of the oxide by water. 
For the purpose of determining the quantities of the peroxide 
of antimony and phosphate of lime contained in the pulvis anti- 
monialis from Apothecaries’ Hall, 200 grains were boiled for a 
long time in about three ounces of strong muriatic acid: 70 grs. 
of peroxide of antimony were left undissolved, and consequently 
the powder consists of 
Peroxide of antimony ........ Ss crjee ys, OO 
Phosphate of lime . .....-++5... PPE 
100 
Inow procured some antimonial powder from another source, 
but of respectability equal to that above-mentioned ; I could dis- 
cover no difference in their appearance, but it was heavier than 
that from the Hall in the proportion of about 100 to 85. With 
this powder, I repeated experiments similar to those just detailed, 
and with similar results: it was a mere mixture of peroxide of 
antimony and phosphate of lime, containing, however, rather 
more of the oxide. It consisted of 
Peroxide of antimony. ........+....+++ 38 
Phosphate of lime. .....-eeseeeeesee- 62 
100 
The experiments now detailed will, I think, sufficiently account 
for the imertness of the pulvis antimonialis; it can only be 
regarded as a mixture of phosphate of lime with the old diapho- 
retic antimony, a preparation of antimony now quite out of use on 
account of its deficiency of power, and which is not likely to 
be increased by admixture with phosphate of lime. 
That the antimony should be thus converted into peroxide 
will be readily conceived, when it is remembered how slowly 
metallic sulphurets part with the last portions of sulphur, and 
animal matter with all the carbon it contains. 
M. Chenevix has proposed to precipitate together protoxide 
of antimony and phosphate of lime ; and provided a mixture of 
protoxide of antimony and phosphate of lime possessed any effi- 
