CONDITIONS OF LIFE OF THE MOULD FUNGI. 503 



The mineral constituents in the case of the higher 

 fungi have the following average composition : 



50 per cent, potash, 1*5 per cent, soda, 1 per cent, 

 lime, 2 per cent, magnesia, 1 per cent, oxide of iron, 

 30 per cent, phosphoric acid, small quantities of silicic 

 acid and hydrochloric acid, and very varying quantities 

 of sulphuric acid. 



According to this analysis, potash and phosphoric acid 

 seem to be of most importance. 



Stutzer* has found that mould fungi washed in water, 

 and dried over sulphuric acid, showed a total of 3'776 

 per cent, of nitrogenous materials, consisting of 3 '026 

 per cent, of proteids, and 1'539 per cent, of nuclein. 



2. The Nutrient Materials of the Mould Fungi. Cor- Nutrient 

 responding to the chemical composition, a large amount m 

 of water is necessary for building up and maintaining 

 the constituents of the mould fungi; also organic sub- 

 stances containing carbon and nitrogen, and of the 

 mineral constituents, chiefly potash and phosphoric acid. 

 The chemical compounds which these nutrient materials 

 furnish, and the relative amount in which the latter must 

 be present, can however only be ascertained by special 

 experiments. 



A series of experiments in this direction were formerly jjaulin's 

 made by Pasteur, and have been carried out in a very thorough experiments, 

 manner by Baulin,f who proceeded as follows : He cultivated 

 Aspergillus niger in a nutrient solution which, as the result 

 of numerous experiments, he had reason to believe was par- 

 ticularly suitable for the nourishment of the fungus, and which 

 may be regarded as the normal solution. It was composed of 



1500 grms. of water. 

 70 Candy-sugar. 

 4 Tartaric Acid. 

 4 ,, ,, Nitrate of Ammonia. 

 0*6 ,, Phosphate of Ammonia. 

 0'6 Carbonate of Potash. 

 0'4 Carbonate of Magnesia. 

 O25 Sulphate of Ammonia. 

 0-07 each of Sulphate of Iron, Zinc Sul- 

 phate, and Silicate of Potash. 



* Zeitschr.f.physiol. Chem., vol. vi., 573. 

 t Eaulin, Compt. rend , T. 50, p. 229. 



