The simpler natural bases / by George Barger.

  • George Barger
Date:
1914
Catalogue details

Licence: Public Domain Mark

Credit: The simpler natural bases / by George Barger. Source: Wellcome Collection.

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    are devoted entirely to animal bases, Chapter V dealing with creatine, creatinine, and other guanidine derivatives, and Chapter VI with adrenaline, one of the most interesting of simple bases. Twenty years ago it could hardly have been imagined that the suprarenal gland constantly secretes into the blood minute quantities of a base having an intense physiological action, and that this base has a simple chemical constitution and can be synthesised. At first adrenaline stood entirely by itself; later some of the putrefactive amines of Chapter I were found to have considerable physiological activity, and one of them, p-hydroxy-phenyl-ethylamine, which resembles adrenaline chemically, was found to have an essentially similar, although weaker, action on the animal organism. There are moreover indications that other internal secretions owe their activity to bases of comparatively small molecular weight. This appears to be the case with the highly active principle of the pituitary body which is possibly a histidine derivative, and shows some analogies to /3- iminazolyl-ethylamine described in Chapter I. Unfortunately hardly anything is known with regard to the chemistry of the pituitary active principle, so that it is only included in Chapter VII (bases of unknown constitution) on account of its physiological importance. Secretine, the substance which when introduced into the blood stream, causes secretion of pancreatic juice, is probably also a base—and like the active principles of the adrenal gland and of the pituitary body, it is moder¬ ately stable in boiling aqueous solution. The case of the bacterial toxins and antitoxins, which are rapidly destroyed below the temperature of boiling water, is very different. After working on the products of putrefactive bacteria, Brieger in¬ vestigated the bases produced in cultures of pathogenic organisms, such as the typhoid and the tetanus bacillus, but the simple bases which he obtained could not be regarded as the principal cause of disease, and his further work on tetanus toxin showed this substance to be extremely active and apparently also extremely complex. We may say “ apparently ” for the following reason. When a minute quantity of an active principle accompanies large quantities of proteins and other colloids it may remain adsorbed on these in such a way as to make a separation impossible, even when the active principle has a comparatively small molecular weight. The difficulties are particularly great when the active principle is very soluble in water but hardly at all in alcohol, as is often the case with bases of the animal body. A good deal of optimism is required for the belief that our present methods will ever suffice for the isolation of bacterial toxins in a state
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