560 Bulletin 78. 



a solution of saltpetre, at the rate of i lb. to 2 gals, of water, was applied to 

 alternate rows of a plat of cabbage plants. The application, which was re- 

 peated on June 4, to, and 16, was made by pouring one or two gills of the 

 solution around the stem of each plant, from a sprinkling pot, from which 

 the rose was removed On June 18, an examination was made of all the 

 plants in 4 rows of the plat, 55 in number, with the following results : 

 Twenty-nine treate 1 plants were attacked by 124 maggots. Twenty-six not 

 treated were attacked by 25 maggots. One of the treated rows was on the 

 outside of the plat, and these outside rows and the ends of the inside rows 

 were more infested than the others. The greater number of maggots found 

 in the treated rows is to be ascribed to this fact, and not to an. assumption 

 that the nitrate of potash attracted the fl}^ The last application was made 

 but 2 days before the examination, but many live larvae, that had apparently 

 just hatched, were found in the treated rows, thus showing that the solution 

 was harmless to the insects. As an additional test, a cabbage plant badly in- 

 fested with maggots was placed in a flower pot. and treated repeatedly with 

 a saturated solution of the salt, but no effect upon the insects was observa- 

 ble." In 1888, the editor of "The Rural New Yorker," p. J49, also reported 

 no success from the use of this substance against the maggots. 



Corrosive Sublimate. 



An editorial in 1864 ("Country Gentlemen, p. 65) states that a contempor- 

 ary recommends i oz. of this substance dissolved in 4 gals, of water to destroy 

 the root maggots. A correspondent to a Canadian journal ("American 

 Cultivator" for April 30, 1881) says all of the London market gardeners 

 secretly use a solution of X oz- of this substance in 4 gals, of water for these 

 maggots. He had used the solution quite extensively, usinj; enough to 

 saturate the ground. But it is not clear from the account whether it is appli- 

 ed as a preventive or whether it kills the maggots. We have but little faith 

 in its effectiveness, but it should be further tested. Remember it is a viru- 

 lent poi'^on and great care must be used in handling it. 



Epsom Salts (Sulphate of Magnesium.) 



In 188 f, one of Miss Ormerod's correspondents reported fair success in de- 

 stroy! 'g the maggots with a solution of this well-known cathartic. It might 

 be well to test it on a small scale. 



Liver of Sulphur (Sulphide of Potassium.) 



In 1887, a correspondent ( " Rural New Yorker," pp. 431 and 626) reported 

 in detail some experiments by which he claimed to have killed maggots on 

 his cauliflowers by pouring a large teaspoonful of a solution on this substance 

 (i oz. to 3 qts. of water at 100 degrees) on the soil around the stalk; 24 

 hours later the maggots were apparently dead, but his account of the appear- 

 ance of his " dead " maggots strongly impresses one that he saw onl}- pupa- 

 ria or the empty shells from which the flies had emerged. 



The next year, at Dr. Lintner's suggestion, Mr. Goff carefully tested the 



