ROOT CHOPS. 50] 



A rough l>u! useful test consists in placing a clean knife blade in the 

 mixture i or a few minutes, rf copper sulphate thai hasnol been neutralised 

 is present, a reddish stain will Ik- left on tin- steel, and it will lie necessary 

 to add more milk of lime, ami then test again. Should there be no mark on 

 the biade this rime it may be considered that the copper sulphate is 



neutralised, though it will he as well to add a little re milk of lime to make 



quite sure. 



A sec md test as to whether or not the copper sulphate has been neutralised 

 c insist ^ of a Iding a few drops of a solution of ferrocyanid • of p >tassium (in 

 the proportion of 1 oz. dissolved in 1 pint of water) to a small quantity of 

 the Bordeaux mixture, preferably in a test tube. If any brown or black 

 discoloration takes place more lime is needed. 



If, however, the proportions recommended above, and the methods of 

 handling described are carefully followed, there should he no reason to fear 

 the burning that free copper sulphate causes. 



Burgundy Mixture. 



In this mixture copper sulphate is again the most important constituent, 

 hut its corrosive action upon the plants is prevented by the use of common 

 washing soda as the neutralise)' instead of lime, only a larger quantity is 

 necessary. 



It often happens that it is difficult to obtain freshly burnt lime for 

 Bordeaux mixture, and the washing soda may then be used to produce 

 Burgundy mixture. 



The formula recommended is as follows : — 



Copper Sulphate (Bluestone) ... ... 8 1b. 



Common washing soda ... ... ... 10 1b. 



Water ... ... ... ... ... 40 gallons. 



The copper sulphate is dissolved in the same way as in the case of 

 Bordeaux mixture, but the Irish Department recommends that the bulk of 

 the water should be used for this purpose when making Burgundy mixture. 

 If 40 gallons of spray is being made, 36 or 38 gallons of water should he 

 poured into a clean barrel and the bluestone suspended in it in a bag. 



The balance of the water should be put in another vessel and th.3 washing 

 soda dissolved in it in the same way. 



When both the materials are fully dissolved, the s ida solution should be 

 poured slowly into the bluestone water, stirring continuously. The blue- 

 stone solution should never be poured into the soda solution. 



Burgundy mixture should be regarded as a substitute for Bordeaux mixture, 

 and should be used at the same times as recommended for it. It cannot, 

 however, be combined with lead arsenate and some other sprays that can be 

 mixed with Bordeaux mixture. (See Spray Leaflet, No. 11," The Combining 

 of Sprays," to be had on application to the Under-Secretary, Department of 

 Agriculture). 



Even when the above conditions are accurately carried out the mixture 

 may not give the best results, owing to differences in the strength of the 

 sulphate of copper and of the washing soda. Those who wish to get the best 

 results should dip a piece of blue litmus paper in the prepared mixture. If 

 the paper becomes red, more washing soda should be dissolved and added in 

 small quantifies at a time to the preparation, and with continuous Stirling, 

 until a fresh piece of paper dipped in the mixture remains blue. One 

 pennyworth of litmus paper, which may be obtained from any chemist, is 

 sufficient for a large number of tests. 



