6o 



Report S.A.A. Advancement of Science. 



butyric bacteria are anaerobic, while the " casse " bacterium is. 

 aerobic (air being a necessary condition of the phenomenon of 

 " casse "). 



A pure solution of sterilized albumen is introduced in bottle (T), 

 as explained above, and constriction (V) sealed. After inoculation,, 

 a current of sterilized air is constantly passed through the liquid. 



After a few days the solution becomes turbid, and a black pre- 

 cipitate, similar in appearance to that formed in broken wine, settles 

 at the bottom of the bottle. This deposit examined under a magni- 

 fication of i,ooo to 2,000 diam. showed very long slender filaments, 

 transparent, inarticulated, and free from incrustrations of colouring 

 matter, mixed with a few bacteria, saccharomyces and specks of 

 organic dust. 



These filaments, which do not seem to have been observed up to 

 the present, would belong to the leptothrix group. They may be 

 considered as the first cause of the disease. 



We may now condense the whole phenomenon in the follow- 

 ing :— 



A bacterium (leptothrix) developing in wines rich in albumen 



acts on that albumen by fixing ox. and water, and produces 



a diastase which has the property of turning rhodoganeine and 



cyanoganeine brown. 



MEANS OF CHECKING THE DISEASE. 



Since this bacterium only develops in wines rich in albumenoid 

 matters, one of the remedies consists in adding tannic acid to the 

 wine directly after fermentation. But by far the most effective means 

 of checking " casse " is Pasteurization by heat, which has given such 

 reliable results with other wine diseases. 



With the object of ascertaining the effect of temperature on this- 

 ferment, series of small sterilized test tubes were filled with recently- 

 broken \.'ine, plugged with sterilized cotton wool, and placed in a 

 water bath, the temperature of which was kept constant. Each series 

 of six tubes Avas sterilized at a different temperature, the temperatures 

 being 60°, 65°, 70°, 75'-* and 8o°C., each tube in each series being 

 left in the water bath for varying lengths of time, i.e., \ min., ^ min., 

 f min., I min., 2 min., and 3 min. 



The following table gives the results of this experiment : — 



