54 Mr. A. W. Blyth. Observations on the [May 15, 



The fatty acids wore extracted from the faecal soaps by acidifying 

 with hydrochloric acid a portion of the excreta already freed from 

 fat by ether, and then extracting with the same solvent. Combustions 

 \ver.; made for nitrogen, carbon, and hydrogen. 



Undigested starchy matters were determined by conversion into 

 sugar by boiling with a dilute acid and then titrating with Pavy's 

 aminoniacal copper solution. The whole analysis is as follows : 



The solid excreta 



(five days). 



grms. 



Water 1695 '29 



Albuminoids 309 "23 



Starchy matters 47 '96 



Fat 776 



Fatty acids 36 77 



Cholesterin 33 '35 



Cellulose and insoluble matters . . . . 66 '69 

 Ash . 8678 



2283 -83 



Summary of Results. 



A good idea of the amount of food actually consumed, or used by 

 the muscular mechanism, may be obtained by giving a sort of balance 

 sheet between the food equivalents and the excreta, thus : 



Ingesta during 



the five Egesta. Difference, 



corresponding days. 



grins. grins. tirni*. 



Water 18,947 -8 .... 11,296 "09 -76517 



Fat 323-15 .... 77 '88 .... - 245 "3 



Carbohydrates.. 3,999*8 114 "65 -3885 "2 



The albuminoids in the food during the five days in which the total 

 cgesta were collected, amounted to 11 79 '2 grms., representing 186*2 

 grms. of nitrogen ; the total nitrogen eliminated through the kidneys 

 during the same period was 117'5 grms., and through the bowels 

 48'8 grms. ; this subtracted from the nitrogen of the food gives a 

 difference of 19'9 grms. ; hence although all the nitrogen excreted 

 is accounted for as derived from the food, some seems to have 

 been retained, and the nitrogenous equilibrium was not quite 

 perfect. 



K. Vierordt (" Grundriss der Physiologic des Menschen," 1877) 

 calculated on the assumption that 1 grm. of carbon completely burnt 

 is equal to 8080 heat-units, and 1 grm. of hydrogen to 34,460 heat- 



