Introduction of Copper Salts. 23 



tibns make me hope that perhaps the most satisfactory results 

 may be obtained by the use of certain mineral solutions, such as, 

 for example, the sulphate of iron or of copper." But no definite 

 experiment had been made up to this date to prove his assertion. 



Prillieux 1 carried on experiments at Nerac for the destruc- 

 tion of the American grape mildew. He found lime to be of 

 little value. Borate of soda, used at the rate of five grams 2 

 dissolved in a liter 3 of water, gave good results, but the various 

 toxics and antiseptics used by him were practically useless. 



A concentrated solution of the sulphate of iron for the de- 

 struction of anthracnose was already regarded as a specific, 4 

 for it had long been used with success in the treatment of 

 the disease. The practice appears to have originated with 

 Schnorf, of llossbach-Meilen, Germany, for he writes as follows 

 regarding its early history : 5 " During twenty years, I have 

 successfully used the sulphate of iron for anthracnose of the 

 grape, in accordance with the following plan : During spring, 

 before the vines start, F dissolve 3 kilos of sulphate of iron 

 in 6 liters of boiling water. When the solution has cooled, 

 I pour it into earthen vessels. The workmen take these into 

 the vineyard and wash the vines with rags, which are dipped 

 into the liquid. This is done but once during the year, in 

 early spring, and the results are uniformly excellent. It has 

 occurred that during certain seasons before the treatments 

 were begun, I lost the entire crop if the weather was cold and 

 moist, while I have rarely failed to obtain a good yield since 

 the applications were made, and I feel well repaid for my 

 trouble. I repeat the washing every year, and other vine- 

 yardists have followed my example with equal success." 



In France it became the common practice to cover the posts 

 and vines with this solution during winter or early spring, a 

 broom or brush being used for the purpose. In some cases the 

 entire post was soaked in the solution for several days. 



P. de Lafitte states 6 that Sept. 20, 1884, Ricaud and also 



1 Jour. d'Ag. Prat. 1882, Jan. 19, 75. 



2 A gram is equal to 15.432 grains. See Appendix. 



3 A liter is equal to 1.056 quarts. 



Jour. d'Ag. Prat. 1883, April 19, 553. 



8 Schweizer Monats-Schrift fur Obfit- und Weiribau, 1878, ix. 155. See also 

 La Vigne Americaine, 1879, May, No. 5. 

 6 Jour. d'Ag. Prat. 1885, Oct. 1, 479. 



