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while a smaller part of the carbon and hydrogen, with the greater 

 part of the oxygen of the starch, aided by additional oxygen ab- 

 sorbed 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 in- 

 organic world ; and as no such compound is formed from starch, 

 under the same circumstances in other respects, without the pre- 

 sence 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. 



The fact that the formation of fat in the animal body is so noto- 

 riously diminished or restrained by exercise, increasing the supply of 

 oxygen, and promoting, therefore, the excretion of carbonic acid and 

 water, he thinks very important, as indicating, along with other 

 facts, the principle that vital affinities do not supersede the usual 

 chemical relations of the elements that are liable to them, but are 

 merely added to these, and allow of a division of those elements be- 

 tween compounds formed by vital and by simply chemical powers. 



He next referred to the important question, now warmly disputed 

 among chemists, whether albumen can be formed in the animal 

 body, or only passes into it, directly or indirectly, fi'om vegetables, 

 where it is believed to be formed, by a vital action, from the 

 elements of starch, and those of ammonia (in whatever way this last 

 may be supplied), the elements of water and a little oxygen passing 

 off at the same time in the usual exhalations of the plant. He 

 pointed out that, by the addition of a full supply of oxygen, it is 

 quite possible that the elements of starch with ammonia in the ani- 

 mal body may divide th>?niselves into two portions — the one con- 

 taining the greater part of the carbon falling by vital affinity into 

 the proportions of the albumen, while the other, absorbing the 

 oxygen, passes off as carbonic acid and water, the constant excretions 

 of animals ; and he conjectured that the elements of ammonia, requi- 

 site for this action, may be supplied in animals by the air which is 

 continually taken into the stomach, in the water and in the saliva 

 which are habitually swallowed, and which will there be under con- 

 ditions very similar to those in which air and water are known to 

 form ammonia. He stated likewise that as it is certain that fat is 



