2. On Vital Affinity. Parts II. and III..

• Published in: Proceedings of the Royal Society of Edinburgh
• Main Author: Alison
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1851
• Subjects: General Engineering; Carbonic acid
• Online Access: http://dx.doi.org/10.1017/s0370164600035884; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0370164600035884

In continuation of his former paper, Dr Alison proceeded to review the chief facts known in regard to the formation of the oils and the albuminous compounds in organized bodies, with the view of illustrating the modification given by vitality to chemical affinities. The formation of fat or oil in vegetables appears to be effected simply by the separation of oxygen from some of the varieties of starch; but in animals, where no oxygen is evolved, and where, nevertheless, oily compounds may certainly be formed from starch (as shewn by Liebig, Chevreul, and Milne-Edwards), this appears to be effected by an affinity of the greater part of the carbon and hydrogen of the starch, for a small part of the oxygen, to form fat, while a smaller part of the carbon and hydrogen, with the greater part of the oxygen of the starchy aided by additional oxygen absorbed from the air, passes off as carbonic acid and water. In both cases, the essential characters of that affinity, which appears to be peculiar to the state of life, lies apparently in the attraction of carbon for hydrogen, with a much smaller proportion of oxygen than exists in the compounds of these elements existing in the inorganic world; and as no such compound is formed from starch, under the same circumstances in other respects, without the presence of living cells, he regards the formation of oil in living bodies as an effect of vital affinity; although admitting that in the course of the decomposition of animal compounds, by various chemical agents, oily matters may be formed by simple chemical action, as in the well-known example of the formation of adipocere from fibrin.