VERDIGRIS COPPER ACETATE. 283 



quicklime or 2 kilograms of slaked lime and 30 gallons of water. 

 The necessai-y dose of sugar may also be added to the bouilliebordelaise. 

 The action of bouillies of this composition is excellent. Later on, the 

 addition of more sugar was advocated. Peglion proposed | lb. for 

 1^ lb, of blue vitriol and Petermann 4 lb. of molasses for 2 lb. of 

 blue vitriol and 4 lb. of lime. The increase in the sugar must be 

 regarded as injurious to the quality of the bouillie, and it throws 

 discredit on a preparation which, after this change in its con^position, 

 lost the masterly qualities imparted to it by Perret and Barth. The 

 amount of copper may be brought to the proportions now used in 

 bouillie bordelaise, say 0-5-1 per cent of blue vitriol, but the dose of 

 sugar, which should never exceed 15 per cent of the blue vitriol used, 

 must also be reduced. Perret's bouillie is a bluish-green liquor with 

 cupric hydrate and sulphate of lime in suspension. The sugar which 

 enters into the bouillie prepared by Perret's and by Earth's processes 

 is not enough to convert the whole of the blue vitriol used into 

 saccharate. The 1-3 lb. added to the bouillie cannot convert more 

 than 1-4-4-2 lb. of blue vitriol into saccharate. The saccharated 

 bouillie contains, therefore, 0-14-0-42 per cent of soluble copper. 

 Perret remarked that by adding sugar to bouillie bordelaise it became 

 more adherent to the leaves than simple bouillie bordelaise, and that 

 its anticryptogamic action was increased owing to the soluble copper 

 salts which it contained. 



Barth was the most zealous advocate of this bouillie which he 

 regarded as the best, as the ideal bouillie. It never burned the leaves, 

 and its adherence was surprisingly perfect. This last property was due 

 to the cupric saccharate being assimilated without injury by the plant, 

 which would so far render it immune to cryptogamic diseases. This 

 opinion has been greatly disputed. It has been shown besides that the 

 plant had no need to absorb large amounts of soluble copper derivatives, 

 but on the contrary, the strong doses absorbed after the use of soluble 

 copper salts always injures the health of the plant. Infinitesimal doses 

 of copper suffice to give to the plant greater resistance against parasitic 

 fuuiji, and if that infinitesimal amount is not directly assimilable, it is 

 rendered so by the juices transpired by the leaves. It is possible, 

 however, that cupric saccharate, an organic derivative of copper, may 

 be directly assimilable by the plant, and that this property may be such 

 as to give it a plus value as a stimulating bouillie. This bouillie, 

 however, cannot have a superior anticryptogamic action to other 

 bouillies, for a bouillie can never act as a destructive agent of the 

 organs of fungi which are distributed in the interior of plants. Its 

 object is to damage the exterior organs of fructification, annihilate the 

 spores, and prevent their dissemination. This end is perfectly attained 

 by bouillie bordelaise. Perret's bouillie was a great improvement on 

 the primitive bouillie bordelaise, when the latter had not the energy 

 nor the adherence of the present bouillies, owing to defects in its 

 composition. But Perret's bouillie now is perceptibly the same as 

 bouillie bordelaise, or such preparations as verdigris bouillies, which 

 along with cupric hydrate contain a certain amount of soluble copper. 

 Girard, agreeing with Gindt and Sendersens, regards Perret's bouillie 



