The graft theory of disease : being an application of Mr. Darwin's hypothesis of pangenesis to the explanation of the phenomena of the zymotic diseases / by James Ross.

Date:
1872
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Licence: Public Domain Mark

Credit: The graft theory of disease : being an application of Mr. Darwin's hypothesis of pangenesis to the explanation of the phenomena of the zymotic diseases / by James Ross. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    9 which arc more or less analogous to fermentation. It is founded upon the physical law enunciated by Laplace and Bertholet, that when a molecule is put in motion by any force, it is able to communicate its motion to another molecule with which it may come in contact. Liebig’s theory is stated in the following terms:—u Contact with a substance itself undergoing the process of decay is the chief condition of decay for all organic substances which do not possess the power of combining with oxygen at common temperatures.”* This theory embraced not only the process of decay or eremacausis, but also the processes of fermentation and putrefaction, and it was extended by Liebig and others to the explanation of the phenomena of epidemic diseases. According to this theory, the cause of epidemic diseases was a malaria, consisting of organic mattei in a state of motor-decay, which, when absorbed into the system, was supposed to be capable of communicating to the fluids of the body the motion it was itself undergoing. The latter doctrine lent itself to the humoral pathology, which regaids all the changes in disease as occurring primarily in the fluids ; and it also followed that the malaiia must be detected, and their effects upon the body investigated mainly by chemical means. So far as fermentation and putrefaction are concerned, this hypothesis is abandoned for the rival vital theory; and, with the gradual growth of solidism in patho- * “ Familiar Letters on Chemistry,” p. 237.