ic Nov., 1910.] Lime icatcr Bordeaux for Spraying. 



7 -'9 



About the same time, in 1884, it was observed at Bourgogne, in 

 France, tliat among the vines deprived of their leaves by the action of the 

 mildew, there were certain spots where the vines had retained their leaves 

 and showed relative freedom from the disease. Where this w'as the case 

 it was remembered that the stakes to which they were trained had recently 

 been impregnated with sulphate of copper, the usual means employed to 

 preserve the stakes from rot. The difference between the portion of the 

 vine attached to the .':take and the rest of it was so striking that there was 

 no doubt about the copper sulphate being a preventive of the disea.se. Of 

 course, these facts were observed and recorded at the time by numerous 

 persons, but Millardet, Professor of Botany in the Faculty of Sciences of 

 Bordeaux, was one of the first to prove by experiment the effect of the 

 mixture on the mildew and to advocate its use, so that it came to be 

 known as the Bordeaux mixture. It was on the 1st of May, 1885, that 

 he communicated the results of his experiments to the Society of Agricul- 

 ture of (iironde, and from this date mav be reckoned the extensive use of 

 Bordeaux mixture as a fungicide. 



RUNNING THE LIME-WATER INTO THE BARREL OF THE SPRAY PUMP. 



The copper sulphate alone could only be applied to trees or vines in 

 the dormant state and not when in leaf, as it scorches the foliage badly, 

 so that lime is added in some form or another to neutralize the acidity of 

 the bluestone. Many modifications of, and substitutes for, Bordeaux 

 mixture have been since introduced, but the principal advances have been 

 in the more economical use of it based upon a knowledge of its chemistry^ 

 in the improved methods of preparation and application, and in the 

 extended list of diseases for which it is a preventive. At first the mixture 

 was swabbed on the vines with a heath broom, whereas now there are 

 spray pumps of various patterns with nozzles producing a fine mist-like 

 spray, and motor spray pumps which are capable of thoroughly spraying 

 large orchards in the shortest possible time. 



Chemistry of Bordeaux Mixture. 



It w\as thought at first that the reaction of the lime on the copper 

 sulphate was a simple one, that it consisted in the sulphate of copper being 



