58 GRAHAM LUSK 



enzymes, that yeast can act only on sugar and produces only alcohol and 

 carbonic acid, emnlsin acts only on amygdalin, converting it into hydro- 

 cyanic acid, henzyaldchyd and sugar; the same principle follows as re- 

 gards the digestive enzymes. The determination of the characteristic 

 metabolism, including the respiratory exchange, the analysis of urine and 

 feces and record of the body temperature upon a single animal, each ob- 

 servation continuing over several weeks, required such unremitting at- 

 tention by a single observer that even one provided with a. powerful 

 constitution found it almost beyond his power of accomplishment. 



Bidder, who had become interested in the lymph flow as a possible 

 measure of the intermediary metabolism, united his work to that of 

 Schmidt and they decided to work together, Bidder edited the part 

 about the digestive juices and Schmidt that about the metabolism and, 

 "as the result of mutual exchange of ideas and intellectual metabolism, we 

 are in entire agreement." 



The intermediary metabolism is practically terra incognita. To in- 

 vestigate this the authors seek especially to determine the bile excretion 

 in relation to the total ingesta and excreta of the body. 



They ask, "Is bile au excrement or not?' 7 Schwann first described 

 bile fistula?. In at least six of his dogs the cause of their death could 

 have been attributed only to the removal of the bile (1844). 



Blondlot disputed as to this being the cause of death (1S4G). 

 They note that the bile solids eliminated daily constitute a three-hun- 

 dredth part of the solids of the body and they inquire into the question 

 of the quantity of bile reabsorbed by the intestine, as follows: "We in- 

 vestigated the content of bile in the feces of a dog weighing 8 kg. during 

 a five-day period. In order to obtain exactly the quantity of feces be- 

 longing to this period the animal was given only meat during the experi- 

 mental period, and before and after the experiment he received a diet 

 of "Schwartzbrod,'' which yields an extraordinarily voluminous feces, 

 greatly resembling the bread itself and therefore easily recognizable. The 

 fecal material between these two portions must have been derived from 

 the meat diet or from the residues of the bile excreted into the intestine." 

 The feces following meat ingestion weighed 07.3 gin. and contained 

 40.9 gm. of dry solids. "Since this fecal matter contained only traces of 

 bile constituents, and since the quantity of bile solids flowing into the 

 intestine must have aggregated 39.52 gm. or nearly the quantity of the 

 entire feces, it necessarily follows that the larger part of the bile must 

 have been reabsorbed. Still more convincing is the fact that 39.5 gm. of 

 bile solids must have contained 2.37 gm. of sulphur, whereas the entire 

 sulphur content of the feces was only 0.384 gm., more than half of which 

 must have been derived from hair, for, excluding the hair in the feces, 

 only 0.154 gm. of sulphur were found. Almost all the biliary sulphur 

 must have been absorbed into the blood and we are therefore convinced 



