1 62 Tannic Acid Fermentation 



Solution A. Solotion B. 



KNO3 10 gram. MgSOi 0-5 gram. 



KaP04 0.5 gram. K^HPO, 0.1 gram. 



MgS04 0.25 gram. KCl 0.5 gram. 



DistilledHjO -....lOO cc. NaNO, 2.0 gram. 



Distilled HsO 1000 cc. 



The source of carbon was cane sugar, tannic acid or gallic acid, 

 either alone or supplementing each other, depending upon the 

 experiment. A 10 per cent concentration of sugar was employed, 

 as experience has shown that the better growth is secured Avith 

 this concentration than with the lower concentration. This fact 

 is developed in a subsequent table. 



Methods of inoculation. In all of the fermentation experiments 

 the method of inoculation employed was that proposed by Hasse- 

 Ibring.i' 



Methods of analysis. The volumetric method of Dreaper'* 

 was used for some experiments, but for most of the work the volu- 

 metric method proposed by Jean^' was used. Both methods have 

 imperfections, but they are approximately accurate. In all cases 

 analyses were checked by duplicate determinations and usually by 

 more. 



Method of washing and weighing the fungus felt. For the experi- 

 ments, the results of which are included in tables I and II, the 

 method used in washing the felt free from gallic and tannic acid 

 was as follows : 



The felt was removed by means of a bent needle and floated on distilled 

 water, the water being renewed until it gave no further coloration. In order 

 to secure the submersed growth, the solution was poured into a cylinder and 

 the submersed growth, which now usually floated on the surface, was then 

 removed by needles. All of tne mycelium was then placed in a crucible, 

 which had been brought to constant weight at 105°, heated for five hours at 

 the same temperature and then weighed. This method, as well as the use 

 of filter paper, possesses obvious disadvantages as well as being inaccurate. 

 For most of the work, therefore, the following method was used : The Gooch 



" H. H. Hasselbring: Carbon Assimilation of Penicillium, Bot. Gazette. 

 xlv, pp. 176-193, 1908. 



" W. P. Dreaper: Estimation of Tannic and Gallic Acid, Chem. News, 

 xc, pp. 111-112, 1904. 



"F. Jean: Die Bestinmiung des Tannins und der Gallussaure, Chem. 

 CentralbL, 1900, pp. 1107-08. 



