Regarding the chemical composition of mushrooms, we have in the past been limited largely to the work of European chemists. Recently, however, some very careful analyses of American mushrooms have been made. The results of these investigations, while in general accord with the work already done in Europe, have emphasized the fact that mushrooms are of very variable composition. That different species should vary greatly was of course to be expected, but we now know that different specimens of the same species grown under different conditions may be markedly different in chemical composition. The chief factors causing this variation are the composition, the moisture content, and the temperature of the soil in which they grow, together with the maturity of the plant. The temperature, humidity, and movement of the atmosphere and other local conditions have a further influence on the amount of water present. The following table, showing the amounts of the more important constituents in a number of edible American species, has been compiled chiefly from a paper by L. B. Mendel (Amer. Jour. Phy. =1=: 225--238). This article is one of the most recent and most valuable contributions to this important study, and anyone wishing to look into the methods of research, or desiring more detailed information than is here given, is referred to the original paper. TABLE I. ===================================================================+ | FRESH | IN WATER-FREE MATERIAL. | | MATERIAL.| | -------------------------------------------------------------------| | W | D M | T N| P N| E E| S I P A| F | A | | A | R A | O I| R I| T X| O N E L| I | S | | T | Y T | T T| O T| H T| L R C| B | H | | E | T | A R| T R| E R| U 8 O| R | | | R | E | L O| E O| R A| B 5 C H| E | | | | R | G| I G| C| L E O| | | | | | E| D E| T| E N L| | | | | | N| N| | T | | | -------------------------------------------------------------------| | % | % | % | % | % | % | % | % | Coprinus comatus |92.19| 7.81|5.79|1.92| 3.3| 56.3| 7.3|12.5| | | | | | | | | | Morchella esculenta |89.54| 0.46|4.66|3.49| 4.8| 29.3| 8.7|10.4| | | | | | | | | | Polyporus sulphureus |70.80| 9.20|3.29|2.23| 3.2| 27.8| 3.0| 7.3| | | | | | | | | | Pleurotus ostreatus |73.70| 6.30|2.40|1.13| 1.6| 31.5| 7.5| 6.1| | | | | | | | | |