678 POISONS : THEIR EFFECTS AND DETECTION. [§ 866. 
Blue Pill (Pilula hydrargyri). —Mercury in a finely divided state, 
mixed with confection of roses and liquorice root ; the mercury should 
be in the proportion of 33-33 per cent. 1 
Mercury Plaster (Emplastrum hydrargyri).— Made with mercury, 
olive oil, sulphur, and lead plaster ; it should contain Hg 33 per cent., 
sulphur 18 per cent. 
Mercurial Ointment (Unguentum hydrargyri). —Mercury mixed with 
lard and suet ; the strength should be 30 per cent, mercury. 
Compound Mercury Ointment (Unguentum hydrargyri composi- 
turn). —Made with ointment of mercury, yellow wax, olive oil, and 
camphor ; it should contain 12 per cent. Hg. 
Liniment of Mercury (Linimentum hydrargyri) is made of mercurial 
ointment, solution of ammonia, and liniment of camphor ; it contains 
about 9 per cent, of mercury. 
Solution of Arsenious and Mercuric Iodides. —This solution contains 
the equivalent of 1 grm. of arsenious iodide and 1 grm. of red mercuric 
iodide in 100 millilitres. 
Mercuric Ethyl Chloride (Hydrargyrum sethylo-chloratum) is used 
as a medicine on the Continent. It occurs in white, glittering, crystal¬ 
line scales, which take on pressure a metallic appearance, and possess a 
peculiar ethereal odour ; it is but little soluble in water and ether, with 
difficulty in cold alcohol, but copiously soluble on boiling, and depositing 
crystals on cooling. It sublimes at about 40° without residue ; on 
quick heating it burns with a weak flame, developing a vapour of metallic 
taste and unpleasant odour. It gives no precipitate with silver nitrate 
nor with albumen. 
Corrosive Sublimate (Mercuric chloride), HgCl 2 = 271; Hg, 73-8 
per cent. ; Cl, 26-2 per cent.—In commerce this salt occurs in trans¬ 
parent, heavy, colourless masses, which have a crystalline fracture ; if 
placed in the subliming cell described at p. 262, it sublimes at about 
1 The chemical composition of blue pill varies according to its age. Harold 
Senier has made a careful series of analyses, with the following result ( Pharm . Journ., 
Feb. 5, 1876) 
Age 
Metallic 
Mercury. 
Mercuric 
Oxide. 
Mercurous 
Oxide. 
Ash. 
Organic 
Matter. 
1 
18 hours 
3249 
None. 
A trace 
1-20 
66-31 
2 
3 weeks 
32-26 
•09 
•25 
1-20 
66-20 
3 
3 months . 
31-60 
•24 
•62 
1-18 
66-36 
4 
3 . 
31-15 
44 
1-60 
112 
65-69 
5 
6 „ . . 
3244 
•50 
•80 
1-70 
64-56 
6 
14 „ . 
29-86 
•98 
2-60 
1-20 
65-36 
7 
19 „ . 
31-59 
•50 
2-50 
100 
6441 
8 
2 years 
28-40 
1-80 
4-22 
2-10 
6348 
0 
(?) • 
30-23 
1-06 
3-24 
103 
6444 
