Fy On ihe Forination of Fat 
Experiment 2. Considerable extrications of gas took place, but 
there was no appearance of fat. 
From these experiments, we learn that the contents of the ce- 
cum, being confined there for some days, are in a state readily 
to be converted into fat by nitric acid, while the contents of the 
rectum are not, probably from being too putrid. 
While engaged in this inquiry, I received from Sir Joseph 
Banks the carcase of a wild swan, which the Hon. Mr. Pelham 
had shot in the neighbourhood of the Humber. On examining 
the ceca, their contents were found to be of a bright green co- 
lour. This led me to propose to Mr. Brande to ascertain by ex- 
periment, whether an admixture of bile had any effect upon the 
process of converting animal substance into fat. The following 
experiments were made by Mr. Brande upon this subject : 
_ Exp. 1. He took two portions of human muscle of the same 
size, and digested one of them in human bile, the other in wa- 
ter, both placed in the temperature of 100°.—In the first day 
the muscle in the wile underwent no change. On the second 
day it became soft in its texture, and had a slightly fetid smell. 
On the third day it became more fetid and, yellow. On the 
fourth it had the smell of excrement, was flabby, very offensive, 
and fatty upon the surface. The portion of muscle, digested in 
water, had undergone no other change in the four days, but be- 
coming slightly putrid, and there was no appearance of fat what- 
ever. 
Exp. 2. A similar experiment to that with the human bile, 
was made with a small portion of beef, and ox’s bile, and the 
results were exactly similar. : 
Exp. 3, The last experiment was repeated in the tempera- 
ture of 60°, In four days the beef became slightly fetid, and of 
a yellow colour; in six days it became more fetid, but there was 
no appearance of fatty matter. 
Exp. 4. A portion of beef cut into pieces was digested in 
ox’s bile, at the temperature of 100°. At the end of the fourth. 
day the putrefaction was more advanced than in Experiment 2 ; 
the beef was washed and heated upon paper, but no greasy stain 
was produced. 
From these experiments we learn, that the bile has a power of 
onverting animal substance into fat; and that the temperature 
of 100°, or nearly so, is necessary for that process. We learn 
also, that this change is produced just as putrefaction is be- 
ginning to take place; and if the substance goes rapidly into 
putrefaction, no fat is formed ; and, what is deserving of observa- 
tion, the peculiar smell belonging to faeces, so different from that 
of putrid matter, is produced at the time that fat is procured. 
Having succeeded in changing animal matter into fat, by 
adding. 
