SYNTHESIS OF FATS ACCOMPANYING INTESTINAL ABSORPTION 29 
time be spent in this procedure, the whole ot the lacteals may soon become emptied. 
It is also necessary to disturb and expose as little of the intestine as is possible at any 
one time, and then when the flow of lymph from one loop has been exhausted to 
replace that and pull out a fresh loop. 
The flow of lymph may be much augmented by gently kneading the portion 
of the intestine from which the lacteal arises. 
Even employing all these precautions, the interval after opening the intestine 
during which the lymph can be collected is a short one, amounting to about fifteen 
minutes. 
The vessels are too small for the insertion of a cannula, and hence the lymph 
was collected by free incision of the vessel, taking care not to injure the accompanying 
small blood vessels, and allowing the lymph to collect upon the mesentery. This it 
does in large drops, which are collected by small glass tubes made capillary at both 
ends by drawing out a glass tube in the blow-pipe flame. The lymph runs readily 
into these tubes when they are held horizontally, with one of the capillary ends in the 
drop of lymph. In this way from one to two dozen small tubes can be charged with 
lymph. Another method which was employed for collection was to suck the lymph 
up by means of a glass tube drawn out fine at one end, and then blow out into a 
porcelain capsule. 
The subsequent process of analysis consists in weighing the tubes and then 
placing them in a test tube containing ether. In a short time the contents of the 
small tubes become transparent from the solution of the fatty constituents, and soon 
after the lymph flows out and the watery portion collects at the bottom, while the 
fatty constituents are dissolved by the ether. The tubes are taken out and washed 
twice with ether, the washings being added to the first portion of ether used for 
extraction. The tubes are then dried and weighed, the difference between this weight 
and the previous one then obviously gives the weight of lymph collected in the tubes. 
The amount which can be thus collected is small, but fortunately deter- 
minations of fatty acid and fat can be made so closely, and the results lie so pre- 
ponderatingly on the side of neutral fat, that no doubt is left that practically all the 
fat in the lacteals of the mesentery is present as neutral fat, and only a small fraction 
as fatty acid. The determination of free fatty acid was made by evaporating the 
ethereal extract to dryness, dissolving in hot alcohol, and titrating with deci-normal 
sodic hydrate solution, using phenol-phthalein as an indicator. 
The neutral alcoholic solution thus obtained was next evaporated almost to 
dryness, a measured volume of standard alcoholic potash (approximately ~) was then 
added, and the mixture boiled for twenty to thirty minutes ; the flask in which the 
boiling took place being fitted with a reflux tube. The contents were then neutralized 
with semi-normal hydrochloric acid, and the difference between the amount of acid 
required and that necessary to neutralize the volume of alcoholic potash originally 
