MINUTE DIVISION OF MERCURY. 
243 
new one in favour of hydrarg. cum creta. Pil. Hydrargyri. 
(Phillips's Pharmacopoeia, 1837.^ — "The mercury in this 
preparation is probably in a state of minute division only." 
Unguentum Hydrargyri. During the trituration with 
the fatty matter, the mercury is probably reduced to the same 
state as that in which it exists in the pilula hydrargyri." 
Hyd. cum Creta. — "I have found that a small portion of 
the mercury is, by the long trituration required, converted 
into peroxide ; and this being the case, the effects derived 
from the use of this medicine are readily accounted for." 
Mr. Phillips does not inform us how he accounts for the 
efficacy of blue pill and mercurial ointment. Dr, Collier re- 
marks — 
Pil. Hydrargyri. {Dr. Collier's Pharmacopoeia, 1837.) 
— " I see no good reason for doubting that the mercury in 
this pill, as in the hydrargyrum cum creta and unguentum 
hydrargyri, is partially oxidized. I have known considera- 
ble quantities of metallic mercury — a pound or more— remain 
for many hours in the alimentary canal, without any other 
effect than what was purely mechanical. 
" If any faith is to be placed on analyses, the exact propor- 
tion of oxidized and minutely divided mercury was stated by 
Professor Brande twenty years ago, although the College 
authority tells us that blue pill is probably nothing but 
metallic mercury minutely divided." 
To complete the explanation, Dr. Collier observes, with 
reference to hydrarg. cum creta, that 
" The name (to be consistent) ought to have been hydrar- 
gyri protoxydum cum creta." 
Adding in a note, 
" It is scarcely possible to render the globules invisible by 
any trituration, however diligent." 
Unguentum Oxidi Hydrarg. Cinerei. {Dr. A. T. 
Thomson's Dispensatory, 1837.) — 4C As the whole of the 
mercury in this ointment is oxidized, it might, a priori, be 
supposed that it would answer all the purposes of the mercu- 
rial ointment ; but it cannot be so easily introduced by fric- 
VOL. viii. — no. in. 31 
