og 
Kiihn,' who. seems to have been one of the first to systematically 
investigate the subject of smut infection and the means for its preven- 
tion, in 1858 recommended the use of 1 pound of copper sulphate for 
each 7 bushels of wheat to be treated. In his experiments the fun- 
gicide was dissolved in enough water to cover the wheat to a depth of 
4 or 5 inches, and in this the grain was soaked for from twelve to 
fourteen hours before sowing. 
Dreisch”? in 1873 showed that if wheat which had been soaked in 
dilute solutions of copper was placed in milk of lime for a few minutes 
the injurious effect of the copper compound on the seed would be over- 
come to a great degree. He recommended the use of a 0.5 per cent 
solution of copper sulphate as being sufficiently strong for treating the 
seed. 
Haberlandt* soaked wheat before planting for six, twelve, eighteen, 
and twenty-four hours in 0.1, 0.5, 1, and 5 per cent solutions of copper 
sulphate. He found that soaking the seed for six hours in a 0.1 per 
cent solution was sufficient to kill all smut spores. - Where the stronger 
solutions were used the seed was injured, the time of germination being - 
considerably prolonged. 
J. Isidore Pierre* tested the effect on seed of a 2 per cent solution 
of copper sulphate at different temperatures. When soaked for three 
minutes at 60° ©. 54 per cent of the seed germinated, and when soaked 
for the same length of time at 50° C. 63 per cent germinated. 
F. Kudelka® compared the germination of wheat soaked for sixteen 
hours in a 0.5 per cent solution of copper sulphate with similar lots of 
seed soaked for the same time in distilled water. Seed germinated in 
a Nobbe tester gave 65 per cent germination for the copper-treated seed 
as compared with 74 per cent when soaked in water. Seed planted in 
the ground and covered to a depth of 1 cm. gave 65 per cent for the 
copper-treated and 67 per cent for the water-soaked. When covered 
to a depth of 3 cm. 24 per cent of the copper-treated seed germinated, 
and 54 per cent of the water-soaked. Kudelka also found that soaking 
for two hours in the solution killed all smut spores and did not materi- 
ally affect the seed. 
Nobbe® has shown that copper sulphate has a corrosive effect on 
various seeds, that the injury done to germination is in proportion to 
the strength of the solution used and the length of time the seed is 
soaked, and that the principal injury is done to the root systems. He 
believes that the best results are obtained by immersing seed from one 
to two hours in comparatively weak solutions, and that the injury is 
1Krankheit der Kulturgewiichse, 1859, p. 85. 
2Untersuch. iiber die Einwirkung Kupferlisung auf Keimung des Weizen, 1873. 
3Landw. Centralbl., 22, 1874, p. 281. 
SAUD MOTO.) Lolo. Dis Lit. 
5Oesterr. Landw. Wochenbl., 1876, p. 1280. 
6Landw. Vers. Stat., 15, 1872, pp. 252-275. 
