New York AGRICULTURAL EXPERIMENT STATION 399 
As regards its strength, when used according to directions, the 
liquid form as put up for 1891 was found too dilute. The direc- 
tions for using are to dilute the contents of one two-pound can in 
seven bucketfuls of water, which may mean anywhere from twenty 
to thirty gallons. Taking the lower number, we should then have 
an equivalent of one and one-eighth ounces of copper carbonate 
to twenty gallons of water, while the official proportions are an 
equivalent of one ounce of copper carbonate in ten gallons of _ 
water. The solution made from this “liquid copperdine” for 
1891 was, therefore, only about half as strong as the official solu- 
tion ; and, if one used thirty gallons of water for dilution, then 
the solution would be only one-third as strong as it should. 
4, A sample of “liquid copperdine,” as prepared for the season 
of 1892, was also examined. It was found to contain 4.73 per 
cent. of copper, or nearly two and one-half times as much copper 
as the sample prepared for 1891. This mixture is, therefore, of 
proper concentration. It is a solution of copper carbonate in 
ammonia. It contained some sulphate. 
ANALYSIS OF “ PREPARED BoRDEAUX MIXTURE.” 
This sample was from a lot prepared for the season of 1892. It 
is put up in dry form. It was found to contain 11.62 per cent. of 
copper. The official mixture contains 15.24 per cent. of copper. 
Hence this “ prepared”? Bordeaux mixture contains only 76.2 per 
cent. as much copper as it should contain. This may be due to. 
incomplete mixing of materials. 
SuMMARY OF RESULTS. 
1. Copper sulphate, in the form of large crystals, may be relied 
upon as being fairly pure; but, wken it is in the form of powder, 
itis always safe to test its purity. The dried form of copper 
sulphate is objectionable on account of the uncertainty of its 
composition, which changes on exposure to air, and, being in 
powdered form, it can readily be adulterated. The comparatively 
low price of copper sulphate does not offer the temptation for 
adulteration that the more expensive form of carbonate does. 
2. Copper carbonate, on account of its relatively high price, and 
also on account of its finely divided condition is, probably, quite 
liable to adulteration, and should always be tested. All the 
