4 
CALABAR BEAN IN OPHTHALMIC MEDICINE. 
25 
four ounces; proof-spirit, two pints: digest for fourteen days, express, and filter. 
Or the tincture may be made in the ordinary way by percolation. 
There are no recognised formulas for the above in the United States Pharma¬ 
copoeia, but as it is important that some definite preparations should be employed 
in this country to avoid mistakes and confusion, we give these formulas as likely 
to answer the purposes for which they may be required. 
Doses .—The dose of Geranium rhizome in powder is from twenty to forty 
grams; that of Geranin, from one to five grains; that of the decoction, from one 
to two fluid ounces ; that of the infusion, from one to three fluid ounces; and that 
of the tincture, from one to two drachms. 
ON THE BEST METHODS OE APPLYING THE CALABAIl BEAN 
IN OPHTHALMIC MEDICINE. 
BY DANIEL HANBURY, F.L.S. 
In the last number of the Pharmaceutical Journal I stated that certain 
difficulties occur in forming a preparation of the Calabar Bean which can be 
conveniently applied to the eye. These difficulties arise from the fact that the 
alcoholic extract which contains the whole of the poisonous principle of the 
bean'* can only be imperfectly dissolved in water, and that its alcoholic solution is 
inadmissible. There is also another difficulty which occurs with all liquids that 
are required to be dropped into the eye, and that is, that the flow of tears which 
instantly follows such an application greatly reduces the amount placed in con¬ 
tact with the membrane,—or at any rate renders it very uncertain. 
These considerations have suggested other expedients for applying the remedy, 
one of which is to use the extract by itself; another is to employ it diffused 
through paper, after the manner recommended by Mr. J. F. Streatfeild for the 
application of atropinef ; and a third is to use a solution of the extract in gly¬ 
cerine. Each of these methods lias certain advantages. The extract, which is 
prepared by exhausting the finely powdered bean with alcohol sp. gr. -838 and 
evaporating the solution, is not a homogeneous body, but contains a small 
amount of greenish fatty oil which separates as the solution is concentrated. 
Its action upon the eye is rapid and powerful. The best means of using it is 
to moisten a camel’s hair pencil with water and then with its tip to rub off a 
minute quantity of extract and apply it to the palpebral con j unctiva of the lower 
lid :—so applied, its specific action ensues in the course of a few minutes. This 
method of the direct application of the extract would probably be hardly advi¬ 
sable in any other than professional hands. 
The method of applying atropine to the eye by soaking a piece of thin bibulous 
paper of definite size in a known quantity of solution of atropine and then al¬ 
lowing it to dry, has been recommended in this country by Mr. Streatfeild and 
in France by Mr. LeperdrielJ. Such paper should be cut into small pieces from 
i to ^ of an inch square, the proportion of atropine being so regulated that a 
single square shall represent a clroj) of the ordinary solution of two grains to the 
ounce. Paper prepared on this principle with a solution of Calabar Bean 
answers extremely well, and promises to afford the most definite method of regu¬ 
lating the quantity of the remedy to be applied. The following is the process 
which I have adopted. One ounce Troy of the bean, reduced to fine powder, is 
to be thoroughly exhausted by hot rectified spirit (-838) ; the solution so ob- 
* Since publishing my former paper, I have ascertained that the finely powdered bean 
deprived of everything that alcohol would remove, is no longer poisonous to rats. 
t Ophthalmic Hospital Report, Jan. 1862, p. 310; also Pharm. Journ., Jan. 1863, p.329. 
+ Bulletin de la Societe de Fharmacie de Bruxelles, Mars, 1863, p. 93. 
