Materials and Formulas. 157 



making the Bordeaux mixture, but in that case twice as much 

 lime should be used as called for by the formulas in which 

 quicklime is mentioned. 1 



The action of lime upon foliage has been studied by Cuboni. 2 

 When this material was first used by the Italians, their endeavor 

 was to cover the grape foliage with a thick and uniform layer. 

 The work of Cuboni shows that light acts upon the chlorophyll 

 under the treated parts in a perfectly normal manner, for treated 

 leaves had a coefficient of transpiration of 7 grams per square 

 centimeter in one hour, while non-treated leaves, under the 

 same conditions, had a coefficient of 7.25 grains, a very insig- 

 nificant difference. It would thus appear that no injurious 

 influence of this nature need be feared from applications of 

 lime or of the Bordeaux mixture. 



Quicklime may be applied alone as follows : 



Lime ^-2 pecks. 



Water 40 gallons. 



This formula allows of much modification, but the thicker 

 the mixture is made the more difficult it is to apply. Its value 

 as a fungicide rests largely in the mechanical action of the lime ; 

 it forms a coating over the parts treated, so that the germinating 

 spore cannot penetrate to the leaf tissue. In other respects its 

 effect is but slight. 



Air-slaked lime is of greater value as an insecticide when used 

 dry, than when mixed with water. In the dry condition, it is 

 effective in destroying snails, slugs, and the larvae of some insects, 

 as the cherry slug. It may also be used as a diluent of poison- 

 ous powders, as hellebore, arsenites, etc. It causes the death of 

 angleworms, whether used dry or with water, and flower pots 

 may easily be rid of them by the use of this material, a satu- 

 rated solution containing sufficient quantities for the purpose. 



Quicklime can be bought for 60 cents to $1.50 per barrel. 



LIME, SALT, AND SULPHUR WASH. A mixture similar to 

 the following was originally used in California as a sheep-dip, 

 but as fruit trees began to drive out the sheep, the applications 

 of the compound were transferred to the trees, and thus it has 

 been very generally used, and has proved to be of value in the 



1 See, also, Millardet et Gayon, Jour, d 'Ag. Prat. 1888, May 17, 693 et neq. 



2 Cited by Viala, " Les Maladies de la Vig-ne," 1893, 118. 



