Dr. ]\Iarcet on the Action of Bile upon Fats. 145 



of the blood is induced, and if enough have been employed, a 

 strongly marked diabetic condition of urine is established. 



Sacrificing an animal and maintaining the circulation by perform- 

 ing artificial respiration, occasions a well-marked diabetes. With 

 the destruction of life, the transformation of hepatine into sugar 

 takes place, and this, being carried away by the blood, is eliminated 

 by the kidneys, and thus renders the urine strongly saccharine. 



Many phenomena which were before obscurely explained, receive 

 a lucid interpretation from the new facts which have now been 

 brought to light. 



" On the Action of Bile upon Fats ; with Additional Observations 

 on Excretine." By W. Marcet, M.D., F.R.S. 



Having formerly observed and communicated to the Societe de 

 Biologic of Paris, that by heating a solution of neutral tribasic 

 phosphate of soda (2NaO . HO . PO5) mixed with animal fatty acids, 

 an emulsion was obtained attended with the formation of a small 

 quantity of soap, while no such action occurred if neutral fats were 

 used instead of fatty acids, I was induced to inquire into the nature 

 of the action of bile on neutral fats and fatty acids (sheep's bile being 

 used), with the final object of throwing, if possible, some additional 

 light on the digestion of fats. These investigations led to the fol- 

 lowing results : — 



1 . A mixture of bile and neutral fats (stearine, oleine and marga- 

 rine), heated to a temperature above the fusing-point of the fat, un- 

 dergoes no change, and no chemical action takes place. 



2. A mixture of bile and fatty acids (stearic, oleic, and margaric 

 acids), heated to a temperature above the fusing-point of the fatty 

 acids, is transformed into a solution, a very few and minute globules 

 only of fat remaining unacted upon from the presence of oleic acid. 

 This solution becomes a perfect emulsion on cooling, and is attended 

 with a chemical decomposition of the bile ; and further, if the emul- 

 sion of bile and fatty acids be filtered when quite cold, and the 

 residue on the filter thoroughly washed with distilled water, the fil- 

 trate and washings mixed together again possess the property of 

 forming an emulsion with another quantity of fatty acids, being also 

 at the same time partly decomposed, although in the previous 

 operation the bile appeared to have exhausted its power on the 

 fatty acids. The filtrate and washings from this second operation 

 again act upon a fresh quantity of fatty acids, and so on ; only in 

 every subsequent operation the proportion of emulsion obtained 

 appears to diminish, and the induced chemical decomposition to be 

 lessened. 



3. Pure oleic acid, when agitated with bile, cold or hot, produces 

 no emulsion or chemical action whatever. 



4. The stomach during digestion has the power of decomposing 

 the fats contained in the food into fatty acids, fats acquiring thereby 

 the property of being acted upon chemically by the bile, and of being 

 transformed into an emulsion. 



Phil. May. S. 4. Vol. 17. No. 112. Feb. 1859. L 



