148 COMPOSITION AND NUTRITIVE VALUE 



the results as pure protein. Indeed, as will be pointed out 

 later, this so-called protein nitrogen, in the present instance, 

 contains a large proportion of nitrogen in a form wholly 

 unavailable for the nutrition of the body. 



Soluble carbohydrates were determined in an approximate 

 manner by extracting the dry substance repeatedly with hot 

 water and then boiling the extract for ten hours with hydro- 

 chloric acid of 2 per cent resulting strength. The sugar was 

 determined as dextrose in the neutralized fluid, by the Allihn 

 gravimetric method. 



Experimental data. Coprinus comatus (Shaggy coprinus). The specimens 

 were freshly gathered and had not yet turned "inky." They varied very 

 widely in size, thirty-six mushrooms weighing 1485 grams, of which 980 grams 

 belonged to the caps (pilous) and 505 grams to the stems. The average 

 weight of a fresh specimen was thus : 



Pileus 27 grams 



Stem 14 " 



Total weight 41 " 



A specimen which had attained the average growth weighed : 



Pileus 43 grams 



Stem 26 " 



Total weight 68 " 



An analysis yielded the following results : 



Water 92.19 per cent 



Total solids 7.81 " 



The dry substance contained : 



Total nitrogen 5.79 per cent 



Extractive nitrogen 8.87 " " 



Protein nitrogen 1.92 " " 



Ether extract 3.3 " " 



Crude fiber 7.3 " " 



Ash 12.5 " " 



Material soluble in 85 per cent alcohol . . 66.3 " * 



Coprinus atramentarius (Inky coprinus). Two separate, freshly gathered 

 lots of this species were examined. The one (a) contained six young small 

 specimens weighing 5.5 grams, or 0.9 gram each ; the other (b) contained 

 eight mushrooms weighing 12 grams, or 1.5 grams each. An analysis gave : 



