1903.] Fats accompanying Absorption from the Intestine. 145 



also determined by Kottstorfer's saponification method (Me supra), 

 and this amount was always found so low as to lie well within the 

 limits of experimental error.* 



To save repetition it may be stated that in each experiment of the 

 series the extract, which in some cases was cell-free and in others con- 

 tained the fresh tissue cells, was divided into four portions. Portion 

 No. 1 had 2 per cent, of sodium oleate and 1 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 four sets of results after digestion will accord- 

 ingly show the effects, if any, of presence of glycerine, as between 

 No. 1 and No. 2; the effect of boiling upon the production of free 

 oleic acid, as between Nos. 2 and 3 ; while No. 4 gives the amount 

 of fatty extractives and action of digestion thereon in the tissues or 

 extracts themselves. 



The four portions were subjected to digestion for a stated period, 

 which varied in the different experiments, and were next evaporated 

 to dryness on a steam bath, after which each dry residue was treated 

 in the following manner : 



Four extractions were made with ether, and the amount of residue 

 on evaporation of the united ethereal extracts gave the total ethereal 

 extractive. 



The ethereal residue was dissolved in hot alcohol and titrated with 

 decinormal sodic hydrate, using phenol-phthalein as indicator, titrating 

 rapidly and taking the first appearance of a pink tinge as the end of 

 the reaction, so as to avoid saponification of any trace of neutral fat 

 which might be present. This gave a figure for the calculation of the 

 amount of free oleic acid present. 



After neutralisation, the alcoholic solution had a measured amount 

 of a standardised approximately JN solution of alcoholic potash added, 

 and was boiled in a flask fitted with a reflux tube for 20 minutes to 

 half an hour. The solution was then titrated back to neutrality with 

 standard JN hydrochloric acid, and the difference gave the amount of 

 caustic potash used in saponifying and hence a figure for the deter- 

 mination of the amount of neutral olein present. 



Expt. 1. Intestinal mucosa cells (pig) in distilled water ; period of digestion, 

 17 hours. In each portion were placed 10 grammes of intestinal mucosa and 

 30 c.c. of distilled water. No. 1 had added 0'8 gramme of sodium oleate and 



* The figures given in the various experiments are intended merely to illustrate 

 this point and not to form determinations of small actual amounts of neutral fat, 

 the amount of alkali apparently required in saponification never exceeding 

 0'25 c.c. of standard alkali. The small amount used is also the only reason for the 

 coincidences in value in the tables. 



