
THE PRINCIPLE OF VITAL AFFINITY. 309 
formed from starch, or by which its elements are held together, does not super- 
sede its natural chemical relations, but only adds a new chemical power to 
those which can operate on it, and allows of a division of the starch between 
the result of a vital and a simply chemical affinity; and, 2. That the vital 
action by which fat is formed or maintained, is of no great strength, as com- 
pared with the simply chemical affinities to which the same matter is liable; 
being superseded simply by an imcreased supply of oxygen. And we cannot 
doubt that, in this as in other vital chemical processes, the oxygen, although 
not taken into the organic compound formed, aids its formation materially, by pro- 
moting, on the principle of divellent affinity, the other parts of the metamorphoses 
whereby itis produced. We shall see afterwards the importance of having it esta- 
blished by this simple example, that the oxygen of the air, when taken in full quan- 
tity into the blood, is capable of combining, somewhere in the course of the circula- 
tion with a part of that carbon and hydrogen, recently absorbed into the blood, 
which, under a smaller supply of oxygen, would form a living texture ; and that 
the combination of these portions of the ingesta with oxygen, are one source of 
the excretions. 
There are other facts which lead to the same conclusion, as to the affinity by 
which fat is formed, being more nearly akin than most vital actions to simply 
chemical affinities; particularly,— 
1. The formation of Adipocere, not from starch, but’ from albumen, after 
vitality is over, when undergoing decomposition under ground, where there is a 
full supply of water and but little air, so that the supply of oxygen is less than 
in ordinary putrefaction, which may be understood thus :— 
C N H O 
48 6 36 14= Albumen 
Add 12 12 Water 
1 Oxygen 
48 6 48 27 
Subtract 36 30 3 Fat 
iY, 6 18 24= Carbonic Acid and Ammonia 


which escape, and the attraction of which for each other, no doubt in part deter- 
mines the result. 
2. Again, in the living body, but in a feeble constitution, along with great 
emaciation, and a deficient supply of oxygen, a morbid deposition of fat some- 
times takes place, in circumstances where it could not have been anticipated, but 
only in particular parts. Some distinct cases of this kind have lately attracted 
attention, one in the kidneys, in one form of Briaut’s disease, another in the 
liver, as in many phthisical cases, and a third in the atheromatous exudations 
VOL. XVI. PART III. 41 
