Dip out a small quantity in a porcelain saucer or shallow bowl, and holding it on a level with the mouth, blow the breath gently into it. If a thin pellicle forms on the surface, more lime must be added. Add and test until it does not form. An excess of lime will not hurt.
Another test is to dip the blade of a clean knife into the mixture. If a thin film of copper forms on it after holding it there a minute or so, more lime must be added.
Use good materials and prepare the mixtures thoroughly.
In making up the various mixtures, never use iron vessels, but use glass, wood or crockery receptacles instead.
Strain all mixtures thoroughly into the spray pump to prevent clogging of the pump or nozzles.
Spray thoroughly and in good season. Be in time.
Do not use mixtures which have been leftover and allowed to stand for some time.
FOOTNOTES:
[L] Orton, W. A., proceedings second annual convention National Nut Growers' Association, 1903, p. 82. 1904.