THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
97 
July SO, 1870.] 
some thoughts on prescribing and compounding, as sug¬ 
gested by this case. 
Muriate of strychnia is not officinal in the United 
States nor British Pharmacopoeias, and is rarely pre¬ 
scribed. It is much less soluble than the sulphate, 
requiring 50 parts of water, at 71° F., for solution 
(Gmelin’s ‘Handbook’). The solubility of iodide of 
strychnia is not found in any authority which I have 
consulted. It is spoken of as very insoluble. My own 
determinations make its solubility 0*54 parts in 100 parts 
of water, at 60° F.* 
When a drop of syrup of iodide of iron is added to a 
cold saturated solution of muriate of strychnia, the in¬ 
soluble iodide of the alkaloid is immediately formed. 
I have before me the prescription alluded to in this 
communication, put up in two ways. In both the mu¬ 
riate of strychnia was previously dissolved in 5iss of 
water. In No. 1 the strychnia solution was mixed with 
the iodide of iron, and the ginger syrup immediately 
added and well shaken. In No. 2 the strychnia solution 
was first added to the syrup of ginger, well shaken, and 
the iodide of iron added. In No. 1 the bottom of the 
bottle is covered with crystals of iodide of strychnia, and 
many floating crystals suspended in the mixture. In 
No. 2 no decomposition is discernible, and after standing- 
four days no deposit has taken place. 
On p. 1418 of the U. S. Dispensatory, 13th edition 
(1870), after quoting from this Journal the experiments 
of Bouchardat and Gobley, on the insolubility of iodine 
combinations with strychnia, the authors add: “ But 
though this fact establishes the impropriety of combining 
solutions of iodine and strychnia in prescriptions , yet it by 
no means justifies the inference drawn from it, that 
iodine might serve as an antidote to strychnia. Indeed, 
the contrary has been proved by the experiments of Mr. 
S. Darby, who found the precipitated iodide of strychnia 
was highly poisonous to the lower animals,” etc. 
We have, in the above quotation, information given 
regarding the insolubility of iodide of strychnia, and the 
impropriety of prescribing iodine and strychnia solutions 
in combination. 
It is clearly the duty of the pharmaceutist to see that 
when potent remedies are presciibed in solution that the 
solution is complete. He ought, also, if allowed to dis¬ 
pense such articles, to be informed regarding decomposi¬ 
tions liable to occur, and, if possible, guard against mis¬ 
chief likely to result therefrom, or else return the pre¬ 
scription to the writer, with his objections clearly stated. 
He should also notice when such a prescription is returned 
for renewal, whether any deposit has taken place in the 
bottle, and remove it by washing, should such be the 
case. The question whether it is Iris duty to mark the 
bottle “Shake wrnll,” when the recipe gives no such 
direction, is one admitting of different opinions; but we 
think, when so marked, the error, if any, is on the side 
of prudence. 
We would suggest to physicians, when prescribing a 
remedy like strychnia in solution to its usual full dose , to 
prescribe it alone, and to give separately whatever else 
may be deemed advisable. We have, in our experience, 
been made aware of changes unforeseen and unknown to 
us until the event developed the facts.— American Journal 
of Pharmacy. 
[*** Inasmuch as the amount of liquid was three ounces, 
equal to over thirteen hundred grains, and the hydriodate of 
strychnine about four grains, it is plain that there was suffi¬ 
cient liquid to keep all of the strychnine in solution.— Ed. 
* Hydrochloric and even acetic acid much increase the 
solubility of the iodide, without apparent decomposition, 
when the acids are very dilute. 
(Sjpjjtm! for Sfaitab. 
LIGHT — continued. 
35Y WILLIAM A. TLLDEN, B.SC. BOND. 
DEMONSTRATOR OF PRACTICAL CHEMISTRY TO THE 
PHARMACEUTICAL SOCIETY. 
7. When light falls upon the surface of a trans¬ 
parent substance, such as a sheet of glass, it is. 
partly reflected from the surface, and the remainder 
enters the glass. Of the latter portion a certain 
part, proportionate to the transparency of the glass, 
is allowed to pass on, is, in other rvords, transmitted; 
the remainder is destroyed, it ceases to be light, and 
is transformed into something else. What becomes 
of this lost light is not known with certainty. 
The light which is transmitted is usually deflected 
on entering the transparent surface ; there is, in 
fact, only one position which the incident ray can 
occupy in which it will not be turned aside from 
following its course. If C 
were the ray of light falling 
upon A B, the surface of glass 
or water, it would proceed 
straight onwards in the direc¬ 
tion CD. But if I, or any 
line inclined to A B, be the 
path of the incident ray, it will 
not go on through i, but will V/ 
be bent in the direction of R. 
The ray thus turned aside is said to be ref racted. 
8. When the substance (e. g. glass) into which 
the incident ray passes is denser than that (e.g. air) 
from which it passes, the ray is refracted, as in the 
figure, downwards towards the hue C D, which is 
perpendicular or at right angles to the refracting 
surface. 
If R were the incident ray passing from the 
denser medium glass into the less dense medium 
air, it would, on the contrary, be bent away from 
this perpendicular in the direction of I. 
This is also shown in the next diagram, in which 
A B and a h are the two par¬ 
allel surfaces of a sheet of 
glass or other transparent 
body. The ray I, passing, 
we suppose, through air, falls 
upon the surface A B, is bent 
downwards so as to become 
more nearly perpendicular; ct 
but on emerging again it as¬ 
sumes the direction R, which 
forms with a h an angle equal 
to that which I forms with 
AB. The refracted ray R, 
after emergence, is therefore parallel to the original 
incident ray I. 
9. Now suppose that we have 
to deal with a wedge-shaped 
piece of glass, instead of a sheet 
with parallel surfaces. We shall 
find that, following the same 
rules, the course taken by the 
ray of light will be that shown 
in the accompanying figure. I 
is the ray incident upon A B ; 
on entering the glass it is turned 
down towards the dotted perpen¬ 
dicular ; on coming to A C, and emerging from the 
