26 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
undoubtedly effected in the intestinal cells (vide infra). In the second place, the 
reaction has an importance as an indication of how the organism is protected from 
the entry into the systemic circulation of absorbed soaps, which, as was first demon- 
strated by Munk,' act as virulent poisons when injected into the circulation, although 
perfectly innocuous when administered by the mouth. 
This protective action of the cells, or of some product contained by them, 
is similar in function to the action of the intestinal cells upon albumoses. 
This action upon soaps has been obtained with extracts of intestinal mucosa, 
abdominal lymphatic glands, and pancreas, and is most powerfully exhibited by 
pancreatic extracts. When a water-clear solution is prepared by dissolving two per 
cent, of sodium oleate in an extract of i in 10 of fresh pancreas, and the solution 
kept at body temperature, within a few minutes the fluid becomes turbid, and when 
examined under the microscope is seen to be full of minute highly refractile globules. 
On standing for some hours, a thick oily layer appears on the top, which, when 
separated by ether and titrated with decinormal alkali, is found to correspond with 
oleic acid. The separation is not due to acidity, for the pancreatic extracts employed 
were alkaline to phenol-phthalein and remained so. The alkali separated from the 
soap does not become free in the solution, for the alkalinity of this does not increase 
during the reaction, but it appears to become stably combined with some substance 
present in the extract. This is further shown by the fact that the extracts containing 
free fatty acid in suspension, or as a creamy or oily layer on the surface, can be 
evaporated down to dryness without recombination occurring, as must be the case 
if tree alkali were present. 
In the earlier experiments, a fear of such a recombination occurring led to 
the adoption of the method of extracting the fatty products, after a certain 
period of digestion, directly with ether, without previously evaporating to dryness. 
It was found, however, that although the first extractions with ether by this 
method gave higher yields of fatty acid than the later ones, yet no definite end result 
could be obtained, since the extractions even after the sixth still yielded appreciable 
amounts of fatty acid. 
This result is obviously due to the considerable solubility of ether in water, 
leading to an increase in the hydrolysis of the sodium oleate solution, and hence 
increasing the amount of oleic acid, which dissolved in the ethereal fraction. 2 
Accordingly, this method was subsequently abandoned, and the method of 
evaporating to dryness and then extracting with dry ether substituted, as was 
previously done by Hamburger. 
The experiments by the first method have, however, a distinct qualitative 
value as a confirmation of the results obtained by the second method, for, although 
1. Arch.f. Anat. u. Physiol., Physiol. Abth. Suppt., 1890, S. 116. 
2. This was shown by the control experiment that ether extracts small quantities of oleic acid when shaken up with 
solutions of sodium oleate in distilled water. 
