OF SOME EDIBLE AMERICAN FUNGI. 



153 



Thus Pavy, quoting from Payen's analyses, announces that 

 in the dried state " mushrooms contain 52 per cent, morels 

 44 per cent, white truffles 36 per cent, black truffles 31 per 

 cent, nitrogenous matter."* In a number of species we have 

 determined not only the total nitrogen, but also the extractive 

 (non-proteid) nitrogen as well as the nitrogen in the residue 

 insoluble after artificial gastric and pancreatic digestion. The 

 " protein " nitrogen multiplied after deduction of the nitro- 

 gen in the undigested residue by the factor 6.25 will give 

 an approximation to the amount of proteid material available 

 through the digestive processes going on in the alimentary 

 canal, and thus throw some light on the true nutritive 

 value of the mushrooms. It is here assumed that the nitro- 

 genous bodies soluble in alcohol are likewise soluble in 

 the digestive fluids ; as to the possible presence of alcohol 

 soluble proteids like zein, gliadin, etc., definite information is 

 wanting at present. 



The first table following gives a summary of the nitrogen 

 content of various species; in the second table the amount 

 of available proteid has been calculated in the manner re- 

 ferred to. 



I. 



* Pavy, Food and Dietetics, 1881, p. 187. 



