PANCREAS. 



107 



But these views, so neat and complete in 

 themselves, and so nicely put forth by Ber- 

 nard, have of late been vigorously assailed by 

 the German school, and their fidelity and 

 conclusiveness altogether impugned. Frerichs, 

 and Bidder and Schmidt, have, by a repetition 

 of Bernard's experiments, as well as by many 

 ingenious and well-devised ones of their own, 

 failed to verify any of his results, but have been 

 led by them to conclusions with which they are 

 altogether discrepant. These experimenters 

 state that they carefully followed all Bernard's 

 directions they tied" the pancreatic duct, 

 and, having previously kept the animals on 

 short food from twelve to twenty-four hours 

 so that there might be no remains of the se- 

 cretion in the intestine, fed them with fatty 

 aliment, and killed them in from four to eight 

 hours. They always found the lacteals 

 "most beautifully injected, and the recep- 

 taculum chyli distended with milky chyle." 



Frerichs found on tying the small intes- 

 tine some distance below the opening of 

 the pancreatic and bile ducts in cats and 

 puppies, and injecting into the bowel below the 

 ligature olive oil and milk, that after two or 

 three hours the lacteals were filled with white 

 chyle. He, however, believes that he has 

 found the extreme comminution of fat, and 

 hence in some measure its resorption, pro- 

 moted by the bile and pancreatic juice; for 

 when in cats that had long fasted, he cut 

 through the small intestine near the middle, 

 injected olive oil into both halves, and tied 

 the two cut extremities, he found the lacteals 

 springing from the upper part of the intestine 

 always far more injected than those proceed- 

 ing from the lower, which he attributes to the 

 bile and pancreatic juice having access to the 

 fat in the upper portion. 



With regard to the permanence of the 

 emulsion produced by the mixture of pan- 

 creatic juice and fat out of the body, Fre- 

 richs and Bernard are quite at issue ; for 

 while Bernard states, that on being examined 

 fifteen or eighteen hours afterwards, it was 

 found to be perfectly maintained, Frerichs 

 affirms that the particles of oil soon separate 

 again on the surface. 



There certainly are some circumstances 

 which detract from the conclusiveness of Ber- 

 nard' s experiments : one is, that the chyle 

 contains far less fatty acids than the ordinary 

 neutral fats ; another, that other animal 

 fluids, as soon as they begin to putrefy, cause 

 a similar decomposition of the neutral fats ; 

 another, that Bernard's experiments merely 

 had reference to the production of this change 

 out of the body. This last deficiency has been 

 filled up by Lenz.* He fed healthy cats with 

 fresh butter, or, if necessary, injected it into 

 their stomachs, and killed them in from six 

 to fourteen hours afterwards. Although all 

 the lacteals and the thoracic duct were dis- 

 tended with milky chyle, no trace of butyric 

 acid could be detected in the stomach and 

 intestinal canal, or in the thoracic duct, the 



* De Adipis Coucoctione et Absorptione. Inaug. 

 Diss. Dorp. Liv. 1850. 



portal vein, or gall-bladder. By further ex- 

 perimental investigation, he found that the 

 metamorphic action was hindered by the acid 

 gastric juice in proportion to the amount of 

 free acid present, that a similar action might 

 be artificially induced by other acids, as di- 

 luted lactic, tartaric, and acetic acid, and that 

 it might be overcome by neutralising the free 

 acid by bile, or by an alkali. Hence he con- 

 cluded, that it is only in exceptional cases that 

 the pancreatic fluid decomposes the neutral 

 fats into acids and bases in the living body. 



The argument derived from the experiment 

 on rabbits has been thus explained away by Bid- 

 der and Schmidt. They say that if the rabbit is 

 killed two hours after the fat has been given 

 it the lacteals given off between the pylorus 

 and the mouth of the pancreatic duct, are fully 

 distended with white chyle very rich in fat ; 

 if not till four hours after the injection, the 

 lacteals situated about three or four inches 

 above the mouth of the duct are still filled ; 

 if at six hours, those only below the duct con- 

 tain white chyle ; and if not till eight or ten 

 hours after, the first lacteals well injected with 

 milky chyle are found to be situated ten or 

 twelve inches below the duct. Hence it must 

 have been by always killing the animals six or 

 eight hours after feeding them with fat, that 

 Bernard was able apparently to maintain his 

 view. The facts of the case, say they, were 

 simply these. The chyle had already passed on- 

 wards from the lymphatics proceeding from the 

 first portion of the duodenum, and there was no 

 more fat to be absorbed in that portion of the 

 intestine when Bernard began the investiga- 

 tion. I cannot admit the correctness of this 

 explanation given by Schmidt and Bidder, 

 because some of the rabbits on which I re- 

 peated Bernard's experiments and verified his 

 results were killed within four, or even three 

 hours after the injection of the lard. 



It was formally maintained by MM. Ber- 

 nard and Barreswill, that the pancreatic juice 

 when acidified had an equally solvent power 

 on the precipitated protein compounds with 

 the gastric juice, and that its acidity or alka- 

 linity alone determined whether it should act 

 on albuminous or amylaceous matters. This 

 opinion has also been refuted by Frerichs. 



Lastly, this physiologist ascribes to the pan- 

 creatic fluid a peculiar power of hastening the 

 conversion of the bile into insoluble products, 

 and so favouring its more perfect elimination. 

 This view has been completely overthrown by 

 the experiments of Bidder and Schmidt, who 

 have shown, first, that the greater part of the 

 bile is not thrown oft' with the faeces, as 

 Frerichs believes ; and, secondly, that the 

 lime, to which Frerichs especially ascribes 

 this power, only exists in very subordinate 

 quantity in the pancreatic fluid.* 



In taking a review of all that has been done 

 with regard to the functions of the pancreatic 

 secretion, we must admit that the only one 

 that has been established beyond dispute is its 

 sugar- making action on amylaceous matters. 



* British anil Foreign Med. Chir. Review. Oil tho 

 " Chemistry of Digestion," by Dr. Day. 



