74 THE REPORT OF THE No. 19 



lines district last spring and saw the dirty, dark green color characteristic 

 of most of the spray that was being used, we both remarked that we could 

 not possibly get such a color with our Guelph lime. On our return I pro- 

 cured, with Prof. Harcourt's assistance, a bushel of lime from Port Col- 

 borne and another from Beach ville. Laboratory tests were made with each 

 of these, and with Guelph and Caledon limes, to see what color of wash would 

 be obtained from each kind. The results were interesting. Port Colborne 

 lime gave a dirty dark green, Beachville a greenish orange or greenish yel- 

 low, Guelph was slightly lighter in shade, Caledon gave a green but one 

 considerably lighter than that from Port Colborne lime. Each kind of lime 

 was boiled for one hour under as nearly as possible exactly similar condi- 

 tions. The formula used was 22 lbs. lime, 18 lbs. sulphur and 40 gals, 

 water. Hence it is quite clear that the color obtained depends solely upon 

 the kind of lime used. For general directions, therefore, it is not possible 

 to say what color must be reached. The best way is to boil vigorously for 

 one hour. By the end of this time all the sulphur will have entered into 

 combination with the lime and further boiling will not make the wash more 

 effective. It should be remembered that if the barrel is nearly full or even 

 half full of water, it will not boil quite so rapidly as if there were only about 

 13 or 14 gals, of water in it. 



Is IT Necessary to Use any Special Kind of Lime? 



"Whether the lime of one's own district will give satisfactory results 

 or not is an important question. There is very little doubt that the lime 

 with a high percentage of calcium in it is more desirable than a lime like 

 that of Guelph, containing nearly 40 per cent, of magnesium. 



This element wall not unite chemically, to any extent at least, with sul- 

 phur, and hence to some degree weakens the wash. However, I have found 

 that even Guelph lime will give good results though not quite so good as 

 Port Colborne or Beachville lime. Of these latter two, Port Colborne was 

 the more convenient to use, because the wash made from it stands up bet- 

 ter than any other I have experimented with, and so requires less agitation 

 in the field. If any one is in doubt about the spraying value of his lime, 

 he could easily have it tested by forwarding a sample to the Chemical depart- 

 ment, but there is little question that good results will be obtained from al- 

 most any kind of lime. It is always easy to send for a bushel of some known 

 lime like Port Colborne and compare results with those from the home lime. 



The Dilution of the Mixture. 



Many farmers dilute with cold water, but it is more desirable that hot 

 or warm water be used so that the spray will be put on fairly hot. There 

 are several reasons for this : (1) It is easier to spray with a warm than a 

 cold mixture because the nozzle is less likely to clog. (2) The spray pene- 

 trates crevices and covers the bark better if put on hot. (3) If the mixture 

 is allowed to cool there is a danger of certain substances crystallizing out 

 in the form of tiny orange needles. This fact suggests that, if for any rea- 

 son the mixture is left over night, it will be necessary to reboil it for a short 

 time to. bring these crystals into solution again. A convenient method that 

 I have used is to dilute with cold water and then turn on the steam for a 

 few minutes to heat the barrel up a few degrees before transferring the 

 mixture to the spray tank. 



