365 
AN IMPROVED METHOD OF MAKING BORDEAUX MIXTURE. 
■ 
By W. T. Swingle. 
Since the first of the year I have had under way rather extensive 
experiments with Bordeaux mixture to determine its effectiveness in 
preventing a fungous disease of the lemon known as scab. The neces¬ 
sity of making large quantities of the mixture soon showed how slow 
and inefficient the common methods for its preparation are. After a 
number of attempts a much quicker and at the same time better method 
was worked out, and it is the object of this paper to call attention to the 
method. It might be noted that the lemon proves to be exceedingly 
sensitive to slight changes in the composition of the mixture, and hence 
is a very good plant to use in determining the best form of this fungicide. 
METHODS OF DISSOLVING THE COPPER SULPHATE. 
Probably the best method of dissolving large quantities of copper 
sulphate without heat is that suggested by Mr. M. B. Waite in 1893 
and described on page 336 of this number of the Journal. By this 
method it is a simple matter to prepare strong solutions containing as 
much as 2 pounds of copper sulphate to the gallon. Moreover, it is 
possible to use large crystals instead of the more expensive and more 
easily adulterated pulverized bluestone. Another method, still more 
expeditious and superior to the old way of pouring hot water on the 
bluestone and stirring it till it dissolves, is to conduct steam into the 
bottom of a barrel containing the copper sulphate and water. With a 
small supply of steam, especially if under considerable pressure, the 
water can be heated in an incredibly short time. Besides, the current 
of steam issuing from the pipe sets the water and crystals in violent 
motion and insures a frequent change of the water in contact with crys¬ 
tals. In all cases where the solution is effected with the aid of heat it 
should be allowed to cool before being used.* 
STOCK SOLUTION OF COPPER SULPHATE. 
As early as 1887 the French viticulturist Bicaudt published an 
account of a method of making a strong solution containing a known 
weight of copper sulphate to each liter. This makes what is commonly 
* While working at the Kansas Experiment Station in 1890, Prof. W. A. Kellerman 
and myself found steam conducted through a small pipe fitted with a stopcock to be 
a most valuable means of keeping the temperature ot the water at 132 u 1. for treat¬ 
ing smut of oats and wheat (see Kellerman and Swingle, Ivans. Agr. Exp. Sta. Bull. 
No. 12, Aug., 1890, p. 49; and Georgeson, Burtis, and Shelton, Kans. Agr. Exp. Sta. 
Bull. No. 29, Dec. 29, pp. 177-178). Mr. W. C. Hewitt, manager of the Sunset Orange 
Company, Stanton, Fla., tells me that he finds steam invaluable in making sodium sul¬ 
phide, kerosene emulsion, and other sprays. This method ot heating is unquestionably 
the best for all who have steam available, and should be generally used by such. 
tRicaud, J. Le traitement du mildiou, la dissolution cuivreuse compare aux 
autres preparations liquides (Jour. d’Agr. Prat., 51 u ann., t. i, No. 3, Jan. 20, 1887, 
p. 90). 
