DISEASES OF THE VINE.] 583 



cent, of sulphate of copper, to make sure that his 

 American vines are well protected. It should not be 

 forgotten that vine-blight made its first appearance in 

 Europe on the foliage of a hybrid- American vine. 



The ravages caused by this disease are unfortunately 

 too well known, and are not so effectually controlled by 

 the use of chemicals, as those of its sister disease the 

 vine-mildew, by the use of sulphur. In certain years 

 with favourable weather the virulence is such that the 

 entire crop of a vineyard is lost in two or three clays, 

 and the aggregate loss to the industry is enormous, but 

 with good preventive treatment undertaken at the proper 

 time the ravages of vine-blight are greatly mitigated 

 even in very bad years, although the very best treatment 

 so far known cannot confer perfect immunity. The best 

 remedies against vine-blight are undoutedly those the ac- 

 tion of which depends on the presence of salts of copper. 

 Millardet in 1885, has proved that 2 or 3 parts of sul- 

 phate of copper dissolved in 10,000 parts ot water are 

 sufficient to kill the spores of Plasmopara, and soon after 

 it was proved that sulphate of copper united with sulphur 

 in the proportion of 3 to 5 per cent., or even more, and 

 applied as a dusting has a distinct action against the 

 disease. This mixture of sulphur and sulphate of copper 

 is now sold ready made, and is applied by means of a 

 duster as a preventive against blight and mildew, but it 

 can be easily prepared by the grower, by dissolving 5 

 kilos of sulphate of good quality in a sufficient quantity 

 of hot water, pouting the solution in a tub containing 

 100 kilos of flowers of sulphur, or better of fine precipi- 

 tated sulphur The moistened sulphur is then allowed 

 to dry and reduced again to a fine povvder. 



The so-called pasta Caffaro which is produced in 

 Brescia by an electrolytic process contains about 16 

 per cent of metallic copper, and is a mixture of 

 chloride of copper, hydratsd oxide of copper, and 



