102 DISEASES OF CROPS. 



It is injurious to the plants." (3) Another remedy is to 

 make a strong solution of sodium sulphate (Glauber's salts) 

 " in -which the seed-corn is to be washed, and afterwards, 

 whilst still moist, dusted over with quick-lime." The 

 reader who is acquainted with chemistry will readily 

 understand the reaction which takes place by referring 

 to the following equation : — 



NaaSOi + CaO = NaaO + CaSO^. 



" The caustic soda (NagO) is fatal to the gerrnination of 

 the spores of bunt " as well as those of smut. (4) Other 

 " steeps" for destroying the germs of disease are or have 

 been used by agriculturists. Amongst these are the 

 following : Arsenious acid and soda, slaked lime, salt, a 

 weak solution of potassium permanganate, and a weak 

 solution of carbolic acid. But all these substances are 

 more or less detrimental to the germinating properties of 

 grains. Damaged grains produce sickly plants, and sickly 

 plants rim the risk of becoming diseased. (5) Mr. J. L. 

 Jensen recommends " treating the seed-corn with water 

 heated to a temperature of 127° F. for five minutes, which 

 destroys the fungal spores without injuring the seed-corn 

 or the resulting crop." But the most effectual and re- 

 liable method, in our opinion, is the use of a solution of 

 iron sulphate. The author's investigations on this subject 

 have been confirmed both in Trance ^ and Germany as 

 well as in England. 



(5) The Parasites of Rice {Oryza sativa). 

 The Rice Weevil (Calandra oryzoe) belongs to 

 the same genus as the common corn weevil {Calandra 

 granaria), the palm weevil {Calandra palmarum), and 



' See Prof. Quantin's paper, Joum. de I'Jgric, 1888. 



