ACTION UPON FATS. 345 



at the commencement of the small intestine, as in other 

 animals, but are first seen from twelve to twenty inches 

 below the pylorus. The anatomical peculiarity in these ani- 

 mals is that the pancreatic duct, instead of opening into the 

 intestine with the bile-duct at the upper part of the small 

 intestine, has its opening from twelve or twenty inches be- 

 low ; just at the point where the chyliferous vessels are ob- 

 served. This fact, which we have frequently confirmed, points 

 directly to the pancreatic juice as the agent principally, if not 

 exclusively, concerned in emulsifying the fats ; while it shows 

 that the bile possesses little or no immediate efficiency in this 

 regard. 



Following out this line of inquiry, and operating with 

 fresh, coagulable pancreatic juice and the liquid fats, or 

 those capable of being liquefied by gentle heat, it was 

 found that slight agitation of this fluid with the fats pro- 

 duced a very fine and permanent emulsion, similar in every 

 respect to the milky fluid found in the lacteals during di- 

 gestion. In fact, comparative analyses of the lymph and 

 chyle have shown that the lattei* liquid is nothing more than 

 lymph, with the addition of fatty emulsion. As soon as the 

 absorption of fat is completed, the lacteal vessels lose their 

 opaque white contents, and carry nothing but colorless lymph. 

 This is one of the great experimental facts upon which is 

 based the view that the pancreatic juice has the property 

 of digesting the fats. Concerning the accuracy of this obser- 

 vation there can be no doubt. The fact has been so fre- 

 quently confirmed, that it must now be considered as estab- 

 lished beyond question ; and we can add our testimony to its 

 accuracy from personal observation. It is true that some of 

 the German physiologists have been unable to confirm these 

 experiments ; l but by carefully following out the process in- 

 dicated by Bernard, which is detailed with great care, we 

 have invariably found his observations to be correct. It 



1 LEHMANN, Physiological Chemistry, Philadelphia, 1855, vol. i., p. 500 

 et seq. 



