On the therapeutics of aloin / by William Craig.

  • Craig, William.
Date:
[1877]
Catalogue details

Licence: Public Domain Mark

Credit: On the therapeutics of aloin / by William Craig. Source: Wellcome Collection.

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    upon rabbits, with the view of ascertaining the action of the resin of aloes, and afterwards confirmed my conclusions by experiments on the human subject; and the conclusion to which I came is thus expressed in the Edinburgh Medical Journal for June 1875:— “ The resin of aloes, when thoroughly exhausted of aloin, possesses no purgative properties/' I still adhere to that opinion. In one of the best manuals of materia medica in this country, and one of the most recent, I mean the very excellent edition of Eoyle’s Materia Medica by Dr Harley of London, reference is made to my paper on this subject, and Dr Harley states that his observations do not support my statement, inasmuch as he found that two grains of resin mixed with three grains of soap purged him freely. It might be a fair question for discussion, what effect the soap had in producing this purgation. In experimenting with cathartic substances we should never use soap, which is itself laxative. Gentian would be a far better substance to use in such cases. I have already mentioned that it is extremely difficult entirely to exhaust the resin of aloin, and I have the authority of Mr Smith to say that the resin of aloes with which Dr Harley experimented, and which was supplied by the Messrs Smith, did contain aloin. In my first experiments with the resin of aloin I obtained similar results, and on communicating these results to Mr Smith, he immediately examined the resin, and found that it contained a small amount of aloin, and afterwards prepared some which he believed to be as nearly exhausted of aloin as resin can well be; and when I experimented with this resin, I found it perfectly inert, even in doses of twelve grains. The Messrs Smith have since supplied Dr Harley with this carefully prepared resin, but what is the result of Dr Harley’s experiments with this resin I am not aware. Dr Farre of London gave to patients doses of three grains of resin of aloes, and says that he found it almost inert, and that it seldom produced any evacuation. I believe that any little purgative effect which he observed might have been due to the aloin it contained. I come now to speak more at length regarding aloin. This I believe to be the active principle of aloes. Aloin exists in all kinds of aloes. Good Barbadoes aloes contains about 25 per cent, of aloin. Aloin occurs in long yellow acicular crystals, trans¬ parent and doubly refracting. It is sparingly soluble in cold water, but freely in ether and chloroform. It is an oxidized hydrocarbon, having the formula C16H1807, according to some chemists, differ¬ ing, however, in different species of aloes in the amount of water it contains. According to Dr Tilden, the aloin obtained from Barbadoes aloes contains three atoms of water ; that from Socotrine aloes, one atom of water; whilst that from Natal aloes is an¬ hydrous. These various kinds of aloes differ also in their solubility and form of their crystals, but are believed to have the same physiological actions. They are generally distinguished as Bar-