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THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [November 23,1872. 
physicians have employed it in the treatment of strych¬ 
nia-poisoning and of tetanus. 
The other vegetable alkaloids examined, all possess, 
though in varying degrees, the same peculiar spinal- 
stimulant action as strychnia. Brucia and thebaia 
exert this action with great energy; codeia and mor¬ 
phia with somewhat less power; and nicotia, atropia, 
and methyl-conia, in a still slighter degree, though 
quite obviously. The result of the combination of each 
of them with a salt of methyl is, as in the case of 
strychnia, to change their chemical constitution from 
that of nitrile bases with triatomic nitrogen, to stable 
ammonium bases with pentatomic nitrogen ; and 
the change of physiological action following this change 
of chemical constitution has been found to consist of a 
removal of spinal-stimulant action, and addition of 
paralysing action restricted to the terminations of the 
motor nerves. The important general fact indicated is, 
that a change of chemical constitution, even when 
it is of a simple kind, may produce a very essential 
change in physiological action; and, although perhaps 
evidence is as yet insufficient to warrant any positive 
assertion, it is extremely probable that all the stable 
ammonium bases have a curara-like action. 
It is necessary, however, to guard against the impres¬ 
sion that the compounds of pentad nitrogen act simply 
as nerve-paralysers ; their action is not necessarily re¬ 
stricted to these structures. In several cases it is, no 
doubt, so restricted; and notable examples of this are 
found in the salts of methyl-strychnium, methyl- 
brucium, and methyl-thebaium, whose nitrile bases have 
probably no other decided action than a spinal-stimulant 
one. In those cases, however, in which the salts of 
ammonium bases are derived from alkaloids that produce 
complicated effects, a restriction of action to the ter¬ 
minations of the motor-nerves does not occur. The 
original actions of the alkaloid, excepting the spinal- 
stimulant one, are retained by the salts of its ammonium 
base; and thus the salts of methyl-atropium not only 
act like curara, but they likewise paralyse the cardiac 
inhibitory fibres of the vagi and dilate the pupils, while 
the salts of dimethyl-conium retain the paralysing ac¬ 
tion on the vagi that is possessed by conia itself. 
In considering how these various facts bear upon the 
connection between chemical constitution and physio¬ 
logical action, it is no doubt essential to remember that 
a change of composition as well as of constitution has 
been produced by the conversion of the nitrile into the 
ammonium bases. In the substances examined by Dr. 
Brown and Dr. Fraser, the composition of the original 
alkaloids was changed by adding to them a salt of 
methyl. Are, then, the subsequent changes of physio¬ 
logical effects produced by the action of the added salt 
of methyl P This hypothesis Dr. Fraser thinks so im¬ 
probable as scarcely to deserve consideration, being op¬ 
posed to the result of various experiments. 
It might also be asked, if the processes by which 
these ammonium bases are prepared do not so profoundly 
modify the chemical nature of the alkaloids from which 
they are derived, that no actual relationship exists be¬ 
tween the new substances and their original sources; 
that, for example, sulphate of methyl-strychnium, though 
derived from strychnia, is in no special manner related 
to sulphate of strychnia—the elements of the latter sub¬ 
stance having been so disarranged in its conversion into 
the former, that the strychnia has been altogether de¬ 
stroyed. As an answer to this conjecture Dr. Fraser 
points out that the ordinary colour reactions of the 
alkaloids are retained by their methyl derivatives. 
These various facts confirm the opinion that chemical 
composition bears some relation to the physiological 
action of active substances, and they also prove that 
this relationship is to an important extent due to the 
arrangement of the atoms in the substance. They ap¬ 
pear, likewise, to point to the conclusion that physio- 
ogical action is often, if not always, the result of a che¬ 
mical reaction between the foreign body and certain of 
the constituents of the vital structures whose action is 
modified by it. The results of investigation with such 
substances as carbonic oxide show, indeed, that physio¬ 
logical action may be chiefly the result of chemical re¬ 
actions. The effects of other substances have not been 
connected with chemical action in so direct a manner, 
but this is to a great extent explainable by the difficul¬ 
ties attending the demonstration of a connection of this 
kind. Although experimental research, in many cases, 
has discovered the exact histological elements which are 
acted upon, the chemical characters of these elements 
have not yet been sufficiently ascertained. We have no 
means of determining their normal conditions with the 
delicacy that is required, and we are, therefore, unable 
to investigate the chemical reactions that almost cer¬ 
tainly accompany modifications of their normal physio¬ 
logical condition during the operation of active sub¬ 
stances. Thus, although we know that the normal 
physiological condition of the terminations of motor 
nerves are modified by the salts of the ammonium 
bases derived from strychnia, brucia, thebaia, etc., and 
that this modification is produced by substances that 
have definite chemical properties, we cannot discover 
what chemical change is produced so long as we are 
ignorant of the special chemical properties possessed by 
these structures. The trustworthy observations of 
Iviihne have shown that a recognizable change occurs in 
the physical characters of the nerve terminations—a 
change which renders their outlines more distinct; but 
we are unable to connect this change with any definite 
chemical reaction. In the course of time, reactions of 
a more delicate kind than any we yet possess will, no 
doubt, be discovered, not only for these structures, but 
likewise for each of the special structures on which the 
physiological action of active substances is localized. 
PREPARATION OF THE BROMIDES OF QUINIA, 
MORPHIA, STRYCHNIA AND CALCIUM.* 
BY GEORGE MACDONALD. 
The bromides of the alkaloids may be readily pre¬ 
pared in small quantities by precipitating a solution 
of their neutral sulphates with bromide of barium. 
Bromide of barium is not met with in commerce, but 
it can be made by saturating solution of hydrobromic 
acid with freshly precipitated carbonate of baryta. 
The following is a good method:— 
Put 1 oz. by weight of bromine and 8 fluid ounces of 
water into a pint jar. Attach a sulphuretted hydrogen 
apparatus, being careful to so place the end of the 
delivery tube that it will touch the surface of the bro¬ 
mine, and pass a stream of sulphuretted hydrogen slowly 
through until the bromine is entirely converted into 
hydrobromic acid. Filter the hydrobromic acid solu¬ 
tion into a capsule, and warm gently until it has lost 
all sulphurous odour. 
To make the carbonate of baryta, to a boiling solution 
of 2 oz. of chloride of barium in a pint of water, add 
solution of carbonate of ammonia (to which a little 
ammonia has been added) in excess, wash the precipi¬ 
tate three or four times by decantation, and afterwards 
transfer it to a filter, and continue the washing until 
the filtrate ceases to produce any turbidity on the addi¬ 
tion of a solution of nitrate of silver, to which a few 
drops of nitric acid have been added. Then remove 
the precipitate from the filter, and mix it with sufficient 
water to bring it to the consistence of thick milk. 
To make the bromide of barium, add to the hydrobro¬ 
mic acid solution small portions at a time of the mixture 
of carbonate of baryta and water, until rather more than 
three-fourths of the mixture has been added. When 
this quantity has been added, apply a gentle heat and 
shake vigorously. Then filter a small portion and test 
* From the ‘ American Journal of Pharmacy.’ 
