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inferior such ready-made Bordeaux mixtures are to the home-made 
freshly-mixed article. One of the best known of these mixtures 
sold in' powder form was tested in two ways. In the first experi- 
ment the powder after, being mixed with water according to the 
directions, was thoroughly shaken up in a glass cylinder, and then 
allowed to stand for five minutes. It was found that the suspended 
matter (containing all the copper) had almost completely disappeared, 
through subsidence, from the upper half of the liquid in so short 
a time as five minutes— the percentage of copper in the upper 
half of the cylinder being only 1*6. Another similar cylinder was 
filled with home-made Bordeaux mixture, and exactly the same 
treatment given to it, but here the tendency of the suspended 
matter (/. e ., all the copper) to subside was very different, — the 
percentage of copper in the upper half of the cylinder, after five 
minutes, being 48*4. In the second experiment, the adhesive 
property of home-made Bordeaux mixture was compared with that 
of the mixture made from the proprietary powder mentioned 
above. Investigations showed that in the case of leaves sprayed 
with home-made Bordeaux mixture, the first shower of rain removed 
only 2*92 per cent, of the copper, and the second shown 3*65 per 
cent, of the copper — making a total washed off of 6*57 P er cent, 
of the copper. In the case of leaves sprayed with Bordeaux mix- 
ture made from the proprietary powder the first shower removed 
46*60 per cent, of the copper, the second shower 5*97 per cent, of 
the copper — making a total washed off of 5 2 *57 per cent, of the 
copper. 
The Irish Department of Agriculture have carried on investi- 
gations for several years past in the spraying of potatoes with 
Bordeaux mixture, both home-made and made from spraying 
powders, and now strongly urge the farmer to prepare his own 
mixture. 
It is clear that on account of the marked tendency of the 
suspended matter to settle, and of the very low adhesive powers, 
all Bordeaux mixtures put up in powder form should be avoided. 
Ready-prepared Bordeaux mixture in paste form stands in quite 
a different category to the above-mentioned Bordeaux powders. 
Through the recent chemical discoveries of Mr. Pickering, Bordeaux 
mixture c m now be prepared by a new process and put on the 
market as a concentrated paste. From the chemical standpoint, 
certain advantages (which cannot be discussed here) are claimed 
for the Bordeaux mixture made from this paste over that made 
by mixing equal quantities of copper sulphate and lime, as 
described above. Of what value these improvements from the 
chemical point of view will prove in practical spraying against 
fungus pests has yet to be ascertained, for there is probably a 
biological side to the question of the action of fungicides. For 
the reason given beiow, I consider that the practical fruit-grower 
should continue to make his Bordeaux mixture with equal parts 
A 
