BACTERIAL BLIGHT OF BEANS. 5^5 



that the two are identical. Bacterium pliaseoli is a motile rod 

 with rounded ends, and with a single polar flagellum. It produces 

 yellowish colonies on nutrient agar, and clouds nutrient broth, 

 with the formation of a ring above the surface of the liquid ;f 

 grows well on potato and other vegetable cylinders, covering the 

 cylinder and filling the water with a solid yellow slime, the starch 

 in the potato cylinders is entirely destroyed. In milk it causes 

 a gradual separation of the casein and the whey ; the former is 

 partially redissolved after some weeks. It liquefies gelatine and 

 blood serum slowly ; produces indol in peptone media, does not 

 reduce nitrates, and produces no acid in sugar broths ; grows very 

 slowly or not at all in Uschinsky's solution ; grows well between 

 25° and 30° C, thermal death point 49-50° C. and is strictly 

 aerobic. 



Preventive Measures. 



Spraying is usually not practicable in the case of such a 

 crop as this, especially at present, when the price of matsrials is 

 almost prohibitive, the best means of preventing bacterial blight 

 are (i) a careful rotation of crops to prevent soil infection, and 

 (2) a careful selection of seed; any sample showing even a small 

 percentage of blight should be rejected for seed purposes. 



Botanical Laboratories, 



Union Department of Agriculture, 

 Pretoria. 



Alcohol, from Seaweed. — Sir Edward Thorpe has 

 recently pointed out the ix)ssibilities of seaweeds as a source of 

 industrial alcohol. Certain seaweeds which are procurable in 

 large quantities may, according to Sir Edward, be suitably treated 

 so as to yield considerable quantities of alcohol. It is said that 

 on an average about 6 quarts of alcohol have been produced at 

 the Pasteur Institute from lOO lb. of red wrack, and if treated at 

 higher pressures on an industrial scale even larger yields may be 

 obtainable. The Journal of Industrial and Engineering Chemistry 

 suggests that if the above views materialise a ready and cheap 

 source of alcohol will be provided, together with the possibility of 

 employment for persons whose livelihood was greatly impover- 

 ished by the loss to them of the keljj industry. The process 

 adopted at the Pasteur Institute is stated to be as follows : The 

 plants were reduced to lo per cent, by evaporation. They were 

 then placed in water containing three to six per cent, of sul- 

 phuric acid at about 6o°C. The acidity is reduced to one per 

 cent., and the sugary liquid with nitrogenous material added in 

 some cases was sprinkled with brew^ers* yeast. This — particularly 

 where nitrogenous material had been added — soon began to fer- 

 ment, the alcohol being recovered in the usual wav by distillation, 

 leaving the residue available for the extraction of potash. 



