34S 



Mary Davies Swartz, 



The coefficients of digestibility of the pentosan preparations, as 

 determined in the usual way from the preceding experiments, are set 

 forth in the following table: 



SERIES A. 

 EXPERIMENT NO. 



PENTOSAN. 



COEFFICIENT OF DIGESTIBILITY. 



For the Dog. 



For Man. 



It is evident from these figures, that pentosans in soluble form dis- 

 appear from the alimentary tract of dogs to a very considerable extent 

 (average 73 per cent) , and that small quantities, ingested by man, do 

 not reappear in the faeces. The insoluble limu preparations appear 

 much more indigestible, an average of 28 per cent being digested by 

 dogs, and 51 per cent by man. 



It must be borne in mind, in interpreting the results of these metabo- 

 lism experiments, that they are at best only approximate. The dif- 

 ficulty of strict separation of the faeces, the fact that the human sub- 

 jects were not kept on a uniform weighed diet, and the errors unavoid- 

 ably introduced by determining many different kinds of sugar as dex- 

 trose, make all of the figures given as "coefficients of digestibiUty," 

 in this and succeeding sections, comparative rather than absolute. 



The Digestibility of Galactans. 



In these experiments, preparations of the water extracts of Irish 

 moss, Limu Manauea, Limu Huna and Limu Akiaki have been fed, 

 without any disagreeable symptoms. The results are given in the 

 tables which follow: 



