EXPEEIMENTS. 221 



Fahr.) ; after a short time, flakes of albumen ; no fermentation 

 up to the eighteenth day ; still neutral after six days. 



II. Ditto, with addition of cane-sugar, at 30 35 C. (8695 

 Fahr.) ; quite as in I ; acid in forty-eight hours, no fermentation. 



III. A solution of sugar with clean aphthae-fungi ; neutral at 

 12 15 C. (53 59 Fahr.); after thirty-six hours, acid; no 

 fermentation ; no addition of aphthae-fungi. 



IV and V. Ditto, but at 3035 C. (8695 Fahr.) ; during 

 the first few hours, slight evolution of gas around the parts of the 

 fungi ; in twenty hours, distinctly acid ; no fermentation ; no 

 addition of aphthae-fungi. 



VI. A minimum of clean aphthae-fungi with water and 

 albumen. Neutral ; at 16 C. (60 Fahr.) ; in sixty-five hours, 

 acid ; no fermentation. 



VII. Ditto, with addition of cane-sugar. Neutral at 30 35 

 C. (8695 Fahr.) 



VIII XII. Ditto, only with variation of the quantities of 

 albumen. After some minutes, a fine flocculent deposit (albumen) 

 round the parts of the fungi, which was soluble in potassa ; 

 a slight evolution of gas for several hours ; gradually a heavier 

 precipitate rising to the surface; on the tenth day, slight fer- 

 mentation ; after from eight to twelve hours, distinctly acid ; 

 increase of fungous sporidia as long as gas continued to be 

 evolved. 



Experiments by Berg on the power of the aphthae-fungus to form 

 acids, and on its increased growth by forming acids in pre- 

 sence of a nitrogenous body. 



Two grains of the scabs of aphthae were put into a solution of 

 sugar at a temperature of 30 35 C. (86 95 Fahr.) After 

 twelve hours, evolution of gas, acid reaction; after thirty-six 

 hours, small fungous flakes ; after sixty hours, a mouldy mem- 

 brane on the surface. The whole mass was then shaken and left 

 to itself; the precipitate was washed until it no longer gave an 

 acid reaction. The deposit was again mixed with albumen and 

 solution of cane-sugar at 30 35 C, (8695 Fahr.); after 

 twelve hours a slight, and after twenty hours strongly acid reac- 

 tion was observed, and evolution of gas, which caused the spores 

 to rise to the surface ; after forty-eight hours many fresh aphthae- 

 fungi appeared. The whole mass was shaken up after four days. 

 One half was put into a glass tube, arid potassa added until it 



