Powders in 1886. 83 



This powder in a certain sense forms a link between the older 

 ones in which the ingredients " ought " to be of value, and the 

 later ones in which every material was known to possess a defi- 

 nite composition and also a more or less definite action as a 

 fungicide. 



The David powder was used for the first time in these exper- 

 iments. It was named in honor of Mr. David, who rendered 

 such material assistance to Millardet. The powder was com- 

 posed of 



Quicklime 30 kilos. 



Copper sulphate 8 " 



As small a quantity of water as possible was used to slake 

 the lime, and to dissolve the sulphate. The latter solution was 

 added to the milk of lime when it had cooled, and then the mix- 

 ture was dried in the sun. When perfectly dry it was ground 

 into very fine powder which was of a blue color. 



Sulphosteatite was also used in these experiments. This sub- 

 stance was often called " steatite cuprique," and to many Ameri- 

 can readers it may be still more familiar under the name of 

 " fostite," a term first used in 1894. This substance was pro- 

 posed by Baron Chefdebien, of Perpignan. 



Millardet used a powder known as " sulfatme," made by 

 Paul Esteve, of Montpellier. It was composed mainly of sul- 

 phur, lime, sulphate of copper, and plaster, and was first made 

 generally known in Progres Agricole et Viticole, Nov. 14, 1884. 



Sulfatine gave the best results of any of the powders as 

 regards fungicidai action. Sulphosteatite proved to be the 

 most adhesive, but it burned the foliage of the vines, and for 

 that reason it required careful distribution. This powder had 

 previously been mentioned as possessing no value against the 

 oidium, and the Bordeaux mixture was spoken of in a similar 

 manner. l David's powder was not so active against the mildew 

 as was the Bordeaux mixture, and in addition it cost about 

 four times as much. More material was required to cover a 

 given area, and its use was not advised from a commercial 

 standpoint. Podechard's powder proved to be practically worth- 

 less, and other growers who used it came to the same conclu- 

 sion. 



i Jvur. d'Ag. Prat. 1886, Nov. 4, 663. 

 D 



