4 o THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
was obtained in each case. In other words, the figures merely show that any amount 
of neutral fat which may be formed under such conditions falls within the limit of 
experimental error. 
In each experiment of this series, a division of the extract into four portions 
was employed. Portion No. I had 2 per cent, of sodium oleate, and i per cent, of 
glycerine added ; No. 2 had 2 per cent, of sodium oleate alone ; No, 3 had 2 per 
cent, of sodium oleate added after previous boiling ; and No. 4 had nothing added, 
and was not boiled. 
A comparison of the results after digestion will hence show the effect, if any, 
of presence of glycerine as between Nos. 1 and 2 ; the effect of boiling upon the 
production of oleic acid, as between Nos. 2 and 3 ; while No. 4 gives the amount 
of fatty extractives and action thereon in the tissues or extracts alone. 
The four portions, after the above preparation, were in all cases subjected to 
digestion for an equal, but variable, period, which is recorded under each experiment. 
The four portions were next evaporated to dryness on a steam bath, and each 
dry residue was then treated by the following method. 
The residue was extracted four times with ether ; the ether was separated off* 
and evaporation to dryness gave the total ethereal extractive, which was weighed. 
The ethereal residue was dissolved in warm alcohol, and titrated with deci- 
normal sodic hydrate, using phenol-phthalein as indicator, titrating rapidly and taking 
the first appearance of a pink tinge to indicate neutrality, so as to avoid saponification 
of any trace of neutral fat which might be present. 
After neutralizing the free fatty acid, the bulk of the alcohol used as a solvent 
for the titration was evaporated off to prevent dilution of the standard alcoholic 
potash, now to be used for saponification. 
The alcoholic potash employed for saponification was made up approximately 
of — strength. As it very slowly changes in strength on standing it was titrated 
against standard — hydrochloric acid, immediately before using for each experiment, 
and the result so obtained used for that experiment. 
In each case 10 c.c. of the alcoholic potash was added and the mixture boiled 
in a flask, fitted with a reflux tube, for twenty minutes. The mixture was then titrated 
back to neutrality with standard — hydrochloric acid. Thus if 10 ex. of the alcoholic 
potash used required c/6 c.c. of - acid, and after boiling with the previously neutralized 
ethereal extract required 9*45 c.c, the amount of alkali used in saponifying any neutral 
fat present would be equivalent to 0*15 c.c. of - hydrochloric acid. 
Experiment 1. Intestinal cells (pig) in distilled water; period of digestion, 
seventeen hours. In each portion 10 grammes of intestinal mucosa, 30 c.c. of distilled 
water ; to No. 1, added o - 8 gramme of sodium oleate and 0*4 gramme of glycerine ; 
to No. 2, o - 8 gramme of sodium oleate only ; to No. 3, o - 8 gramme of sodium oleate, 
after previous boiling ; to No. 4, nothing added and not boiled previous to digestion. 
