32 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
These figures show that the greater part of the fatty material present in the 
mucosa is in the form of neutral fat, but that the percentage of free fatty acid is 
much greater than that in the lymph collected from the mesenteric lacteals (see 
previous series of experiments), showing that the process of transformation in the 
cells is in progress and incomplete. 
The results can, however, only be taken as approximate, since it is impossible, 
even with the most careful washing, to be certain that all the adherent, unabsorbed 
and unchanged fat is washed out from between the villi. 
Experiments on the Action of Pancreatic, Lymphatic, and Intestinal 
Tissues and of Cell-free Extracts Prepared from these Tissues upon 
Solutions of Soap and Glycerine 
These experiments were commenced with the view of determining whether the 
synthesis of neutral fat, described by Ewald, was due to the action of an enzyme 
contained in the intestinal cells, which might be separable from them, or whether such 
a synthesis occurred only in presence of the surviving, though isolated, cell. 
Hence the first experiments were conducted only with filtered and centri- 
fugal ized extracts, but negative results having solely been obtained with such extracts 
(so far as such synthetic action was concerned), similar experiments were also 
instituted with extracts containing cells, and in addition, in order to obtain informa- 
tion as to the action of all types of cell involved in fat absorption upon soap and 
glycerine solutions, comparative experiments were carried out with cells and extracts 
of the pancreas and abdominal lymphatic glands. 
The tissues and extracts used were prepared from glands of the cat, dog, ox, 
or pig, and similar effects were in all cases obtained. 
In the case of the intestinal mucosa, the intestine taken from a freshly killed 
animal was cut open longitudinally from end to end, and then thoroughly 
washed either in a stream of running tap water or with 0*75 per cent, solution of sodium 
chloride. In the earlier experiments saline was employed, but in later experiments, 
in which water was subsequently to be used as an extractive agent, water was used 
for preliminary washing out, and as this was found not to cause any alterations in the 
property of the extracts, in the later experiments water was always used to wash the 
surface, even when saline was to be employed later as an extractive agent. It may 
be stated here that no difference was ever found throughout the series of experiments 
in the action of extracts made, on the one hand, with distilled water, and on the 
other hand with saline solutions containing 0*75 per cent, of sodium chloride. 
The mucous membrane, after thorough washing, was scraped off from the 
intestine in lengths of three to four inches at a time by laying it flat on a glass plate 
and scraping lengthwise with the back of a table knife. In this way a soft semifluid 
