FUNGICIDES 



21 



The most complete practical directions for mak- 

 ing the Bordeaux mixture are those published by 

 Professor B. T. Galloway, United States Department 

 of Agriculture, in Farmers' Bulletin No 38, which I 

 quote at length : 



'Tt has been found," writes Mr Galloway, ''that 

 the method of combining the ingredients has an 

 important bearing on both the chemical composition 

 and physical structure of the mixture. For example, 

 if the copper sulphate is dissolved in a small quantity 

 of water and the lime milk diluted to a limited extent 

 only, there results, when these materials are brought 

 together, a thick mixture, having strikingly different 

 characters from one made by pouring together weak 

 solutions of lime and copper sulphate. It is true, 

 furthermore, that if the copper sulphate solution and 

 lime milk are poured together while the latter or both 

 are warm, different effects are obtained than if 

 both solutions are cool at the moment of mixing. 

 Where the mixture has been properly made there 

 is scarcely any settling after an hour, while the 

 improperly made mixture has settled more than half. 



''Briefly, the best results have been obtained from 

 the use of the Bordeaux mixture made in accordance 

 with the following directions : In a barrel or other 

 suitable vessel place 25 gallons of water. Weigh out 

 6 pounds of copper sulphate, then tie the same in a 

 piece of coarse gunny sack and suspend it just beneath 

 the surface of the water. By tying the bag to a stick 

 laid across the top of the barrel no further attention 

 will be required. In another vessel slake 4 pounds 

 of lime, using care in order to obtain a smooth paste, 

 free from grit and small lumps. To accomplish this 

 it is best to place the lime in an ordinary water pail 

 and add only a small quantity of water at first, say 

 a quart or a quart and a half. When the lime begins 



