These are thin discs of gelatine with some glycerine, each weighing about 1/50 th grain and containing a small quantity of an alkaloid. They are chiefly used for local application to the eye. They may sometimes be convenient for preparing solutions for hypodermic injection by dissolving them in a few drops of water.

Lamellae Atropinae (1/5000 th grain in each). ,, Cocainae (1/200 th grain in each). „ Physostigminae (1/1000 th grain in each).

Linimenta. Liniments or Embrocations.- These are preparations for rubbing or painting on a part of the body in order to produce local stimulation or relieve pain. The basis of most of those in the British Pharmacopoeia is olive oil, and of those in the United States Pharmacopoeia cotton-seed oil.1 Camphor is added to most of the liniments in the B.P. for its local stimulant action, and also that its strong smell may lessen the risk of the liniment being used internally. There are four exceptions in the B.P. - the liniments of ammonia, lime, croton oil, and iodide of potassium with soap. With the exception of the liniment of lime all these contain very strong smelling substances, namely, ammonia in the corresponding liniment, cajuput oil in the croton oil liniment, and oil of lemon in the iodide of potassium and soap liniment.

Camphor is not contained in the liniments of the U.S.P., with the exception of the liniments of belladonna, camphor, chloroform and soap.

Soap is used to give a lubricating quality to four liniments in the B.P., viz. opium, iodide of potassium with soap, soap and turpentine; and to two in the U.S.P., viz. chloroform and soap. In the compound mustard liniment, whose composition is nearly the same in the B.P. and the U.S.P., castor oil is used as a lubricant along with alcohol. In one, the turpentine liniment of the U.S.P., the lubricating substances are lard and yellow wax.

Three liniments in the B.P., aconite, belladonna, and iodine, and one in the U.S.P., belladonna, are really exceedingly strong solutions of active principles in spirit with camphor added for the purposes already mentioned.

The liniments last mentioned contain no fatty substances as lubricants, nor does the croton oil liniment of the B.P., compound camphor liniment (B.P.), nor the linimentum cantharidis (U.S.P.). Croton oil liniment (B.P.) is a solution of croton oil with cajuput oil in spirit. The compound camphor liniment is a mixture of strong solution of ammonia with rectified spirit, camphor, and oil of lavender.

1 I have been told that a great deal of what is sold as olive oil in Great Britain is really cotton-seed oil.

The linimentum cantharidis (U.S.P.) is a solution of the active principles of cantharides in turpentine. The difference in composition between the ordinary camphor liniment (B.P.), which is simply a mixture of camphor and olive oil, and the compound camphor liniment should be carefully borne in mind. The linimentum terebinthinae aceticum (B.P.) consists of oil of turpentine and acetic acid mixed with ordinary camphor liniment. But if anyone, thinking to increase its efficacy, should add to it compound camphor liniment, the acetic acid and ammonia would neutralise one another more or less completely, and the activity of both liniments would be to a great extent destroyed.

B.P. (16)

The proportion of ingredients is put after each constituent.

Linimentum

Basis

Solvent

Adjuvant

Vehicle

Aconiti . .

Aconite root (20)

Rectified spirit (30)

Camphor (1)

Ammonias .

Liquor Ammonias (1)

Olive oil (3)

Belladonnas .

Belladonna root (20)

Bectified spirit (30)

Camphor (1)

Calcis . .

Liquor Calcis (1)

Olive oil (1)

Camphorae .

Camphor (1) .

Olive oil (4)

Camphorae Compositum

Camphor (1) .

Rectified spirit (6)

Liquor ammonias fortior (2)

Chloroformi .

Chloroform (1)

Liniment of Camphor (1)

Crotonis. .

Croton oil (2) .

Rectified spirit (7)

Cajuput oil (7)

Hydrargyri .

Mercury ointment (1)

Liquor ammonias (1)

Liniment of Camphor (1)

Iodi . .

Iodine (5)

Iodide of Potassium (2)

Glycerine (1)

Rectified spirit (40)

Opii . .

Tincture of Opium (1)

Liniment of Soap (1)

Potassii Iodidi cum Sapone

Iodide of Potassium (12)

Glycerine (8) .

Curd Soap (16)

Water (80)

Oil of Lemon

(1)

Saponis . .

Hard Soap (16)

Water (32) .

Camphor (8)

Rectified spirit (128)

Oil of Rose-mary (3)

Sinapis Compositum

Oil of Mustard (1.4)

Castor oil (7) .

Ethereal extract of Me-zereon (1)

Camphor (3) .

Rectified spirit (44)

Camphor (1)

Terebinthinas.

Oil of turpentine (16)

Soft Soap

Water (2)

Terebinthinae Aceticum

Oil of turpentine (4)

Glacial Acetic Acid (1)

Liniment of Camphor (4)

u.s.p. (10).

Linimentum

Basis

Solvent

Adjuvant

Vehicle

Ammoniae

Liquor Ammonias (3)

Cotton-seed oil (7)

Belladonnae .

Fluid Extract of Belladonna (95)

Camphor (5)

Calcis . .

Lime water (1)

Cotton-seed oil (1)

Camphorae .

Camphor (1) .

Cotton-seed oil (4)

Cantharidis .

Cantharides (15)

Oil of Turpentine (85)

Chloroformi .

Chloroform (4)

Soap liniment (6)

Plumbi Sub-acetatis

Solution of Subacetate of Lead (4)

Cotton-seed oil (6)

Saponis .

Soap (10)

Water (20) .

Camphor (5) .

Alcohol (70)

Oil of Rosemary

Sinapis Com-positum

Volatile Oil of Mustard (3)

Castor oil (15)

Extract of Me-zereon (2)

Alcohol (74)

Camphor (6)

Terebinthinae.

Oil of Turpentine (35)

Resin Cerate (65)

Liquores. Solutions. - These are solutions of active substances in water, either alone or with the aid of other solvents.

b.p. (48).

Dose.

Liquor

Antimonii Chloridi ..........

"

Ammoniae........................

10-30 m.

"

" Foritor............

3-10 m.

"

Ammonii Acetatis............

2-6 fl. dr.

"

" " Fortior

25-75 m.

"

" Citratis..........

2-6 fl. dr.

"

" " Fortior

1/2-1 1/2 fl. dr.

"

Antimonii Chloridi ..........

"

Arsenicalis........................

2-8 m*

"

Arsenici Hydrochlorici..............................

2-8 m*

"

Arsenii et Hydrargyri

Iodidi.........................

"

Atropinae Sulphatis.........

1-4 m*

"

Bismuthi et Ammonii

Citratis...................

1/2-1 fl. dr.

"

Calcii Chloridi....................

"

Calis....................................

1-4 fl. oz.

"

Calcis Chlorinatae..............

"

" Saccharatus...........

15-60 m.

"

Chlori.....................

10-20 m.

"

Epispasticus.........................

"

Ferri Acetatis.......................

"

" " Fortior

"

" Dialysatus...............

"

Perchloridi...........................

10-30 m.

"

" " Fortior

u.s.p. (27)

Dose.

Liquor

Acidi Arseniosi.................

2-8 m.

"

Ammonii Acetatis..............

1/2-1 1/1 oz.

"

Arsenici et Hydrargyri

Iodidi.................

5-10 m.

"

Calcis...............................

2-4 fl. oz.

"

Ferri Acetais....................

2-10 m.

"

" Chloridi................

"

"

" Citratis...................

10 m.

"

" et Quininae Citratis..................

10-20 m.

"

" Nitratis...................

5-20 m.

"

" Subsulphatis ............

3-6 m.

"

" Tersulphatis.....

"

Gutta-perchae....................

"

Hydrargyri Nitratis.............

"

Hydrargyri Nitratis............

5 m.

"

Magnesii Citratis......

6-12 fl. oz.

"

Pepsini...............................

1/2-2 fl. oz.

"

Plumbi Subacetatis ...

"

" Subacetatis DiIutus.............

"

Potassii............................

10-60 m.

"

" Arsenitis..............

5 m.

"

" Citratis..................

1/2-2 fl. oz.

"

Sodae.................................

10-60 m.

"

" Chloratae..................

30-60 m.

"

Sodii Arseniatis.................

3-8 m.

B.P.

Dose.

Liquor

Ferri Pernitratis......

10-30 m.

"

" Persulphatis .............

"

Gutta Percha.......................

"

Hydrargyri Nitratis

Acidus...........................

"

Hydrargyri Perchloridi........................

1/2-2 fl.dr.

"

Iodi..................................

**

"

Lithiae Effervescens........

5-10 fl. oz.

"

Magnesii Carbonatis .......

1-2 fl. oz.

"

" Citratis..............

5-10 fl. oz.

"

Morphinae Acetatis ........

10-60 m *

"

"' Bimeconatis

"

" Hydrochloratis............................

"

"

Plumbi Subacetatis..........

"

" " Dilutus

"

Potassae.........................

"

" Effervescens.....

5-10 fl. oz.

"

Potassii Permanganatis.............................

1-4 fl. dr.*

"

Sodae................................

10-60 m.

"

" Effervescens...........

5-l0 fl.oz.

"

" Chloratae...............

10-20 m.

"

Sodii Arseniatis...............

5 10 m.*

"

" Ethylatis..................

"

Strychninae Hydrochloratis.......................

5-10 m.*

"

Zinci Chloridi.....................

U.S.P.

Dose.

Liquor Sodii Silicatis........................

" Zinci Chloridi......................

The strength of the liquors marked with an * in the preceding list has been changed from 4 grains to 1 fluid oz., or 1 in 109 (B.P. 1867) to 4 1/2 grains in 1 fluid oz., or 1 in 100 in the B.P. 1885. The strength of the one marked ** has been increased from 5 in 109 to 5 in 100.