138 



THE MAKING AND APPLICATION OF BORDEAUX 



MIXTURE. 



E. S. Salmon, F.L.S., 

 Mycologist to the South-Easteni Agricultural College, Wye, Kent. 



I. The Making of Bordeaux M^rfwr^.— Directions as to the best 

 method of making Bordeaux mixture have already been given in this 

 Bulletin. In order, however, to make the present articles more 

 complete, we reprint the following from the Journal of the Board of 

 Agriculture, Vol. XVI , No. 10. 



" Bordeaux mixture for spraying fruit-trees generally (excluding 

 peaches) should be made according to the following formula and in 

 the following manner : — 



Copper sulphate ('* bluestone ") 4 lb. 



Quicklime (in lumps)... ... 4 lb. 



Water ... ... ... 50 gallons.; 



Dissolve the 4 lb. of copper sulphate in a wooden tub or bucket — 

 iron or tin vessels must not he used. The easiest way to do this is 

 to suspend the material, wrapped in a piece of coarse sacking, in 

 a few gallons of cold water, from a stick placed across the top of a tub, 

 or wooden bucket. If this be done over night, the copper sulphate 

 will be found to be dissolved in the water by the morning. (If 

 hot water be used, the copper sulphate can be placed at the bottom of 

 the tub or bucket, and be dissolved in a few minutes.) Then add 

 water to make twenty-five gallons. Now take the four pounds of 

 quicklime, and put it in a tin pail. Add a few pints of water until all 

 the lime is slaked, taking care to add only a little water at first ; 

 in this way a thick creamy paste is obtained. Add water to make 

 twenty-five gallons. We have now twenty-five gallons of copper sul- 

 phate solution, and twenty-five gallons of " milk-of-lime." When the 

 two substances are thus diluted with water, they can be mixed 

 together by pouring one into the other, or a bucketful of each 

 can be poured simultaneously or alternately into a third tub, — a 

 wooden bucket being used for the copper sulphate solution. The 



I In purchasing copper sulphate an article of 98 per cent, purity should be demanded , 

 substances described as "agricultural bluestone" or "agricultural sulphate of copper" 

 must be avoided, as these are usually adulterated with iron sulphate. In this Jounml for 

 September last a number of cases were recorded of the sale in this country of adulterated 

 copper sulphate ; it is clear, therefore, that it is important for the fruit-grower to insist 

 on an article of 98 per cent, purity. 



\ The strength of Bordeaux mixture at present most widely recommended in the United 

 States is 4ilb. of copper sulphate, 44 lb. quicklime, 50 gallons flmperial) of water. This 

 strength is expressed in America by the formula 4 : 4 : 50, since, as Mr. S. U. Pickering 

 has lately pointed out, the relative value of the American and Imperial gallon is different, 

 the former weighing 8"345 lb. and the latter 10 lb. As, however, excellent results hare 

 followed the use in this country of Bordeaux mixture made of the strength 4 : 4 : 50 

 (Imperial), and as, further, some "scorching" is liable to occur on some varieties of 

 apples, it would seem advisable, for the present at any ra1<«", for the English grower to 

 continue to use this as his " standard " mixture. 



