EXPERIMENTS. 219 



benefited, it can only be done by submitting the fungi, which 

 form a mouldy layer on albuminous substances, to the remedies 

 employed in the experiment, and by placing fungous elements 

 for some time in the solutions of such remedies, watching 

 whether they continue to grow when brought together with fresh 

 albumen. 



Experiments on the question whether the scabs of aphthae have 

 the power of converting milk-sugar into lactic acid, and thus 

 acting as a kind of ferment, and simultaneously producing an 

 evolution of carbonic acid and the generation of acetic acid ; 



1. A glass tube was filled with cane-sugar dissolved in eight 

 parts of water. Reaction neutral ; after seven days, still clear 

 arid neutral. 



2. A glass tube was filled with milk-sugar. Reaction neutral ; 

 after seven days, like No. 1. 



3. Ditto, with a thin mucilage of arrow-root starch. Reaction 

 neutral; after seven days, still neutral; a deposit of starch- 

 envelopes. 



4. A tube was filled with human milk. Reaction slightly 

 alkaline ; after twelve hours it was sour, and coagulated slightly 

 after twenty-four hours. 



5. Ditto, with cow's milk. Reaction slightly acid ; after ten 

 hours, found to have almost completely coagulated. 



6. Ditto, cane-sugar, with two grains of scabs of aphthaB. 

 Reaction neutral ; after twelve hours, acid reaction ; after thirty- 

 six hours, acid, and a cloud of fresh spores of aphtha?. 



7. Ditto, with two grains of yeast-fungi. Reaction neutral ; 

 after one hour, fermentation and acid reaction. 



8. Ditto, with two grains of acid stomach of a child. Reaction 

 neutral ; after nine hours, acid ; after thirty-six hours, strongly 

 acid, the stomach breaking up on shaking; three or four days 

 later, the liquid opalized, and exhibited some sporidia resembling 

 the aphthae- fungi, some fine fibres like the tooth-alga. 



9. A tube contained milk-sugar with two grains of scabs of 

 aphthse. Reaction neutral ; after nine hours, acid ; after twelve 

 hours, slight fermentation ; in four or five days, a mouldy mem- 

 brane, with sporidia of the aphthae-fungus without stalks. 



10. Ditto, with two grains of yeast-fungus. Reaction neutral ; 

 evolution of gas in the course of an hour ; acid without fermenta- 



