38o The Canadian Horticulturist 



sulphate. (Directions for preparing these solutions are to be found in Bulletin 

 lo of the Experimental Farm series.) Spraying with the fungicides, each acre 

 of vines would receive during the season the equivalent of i pound to i ^ pounds 

 copper sulphate. It is thus made manifest that by this treatment — one highly 

 recommended by those who have had experience with it — no such quantity as 

 1 08 pounds of copper sulphate is required per acre. 



By far the greater amount of the copper that reaches the ground is in a con- 

 dition insoluble in water, or becomes so after a short time. In the case of 

 Bordeaux mixture, I would point out that copper sulphate, as such, ceases to 

 exist immediately after the addition of the lime. Sulphate of lime (land plaster) 

 and an insoluble compound of copper resulting. The argument, therefore, that 

 the sulphuric acid of the copper sulphate combines with the potash of the soil, 

 which is subsequently lost, does not hold good. The sulphate of lime does, to 

 a limited extent, set free potash in the soil, in a condition assimilable by plants, 

 and on account of this beneficial function, land plaster is often used as a fer- 

 tilizer. The presence of minute quantities of an insoluble copper compound 

 cannot, in my opinion, affect disastrously the fertility of the soil, nor act as a 

 poison to plants. The acid fluids secreted by rootlets may have the power of 

 rendering such soluble and thus capable of absorption, but unless the soil were 

 heavily charged with copper compounds, no evil effects from this cause need be 

 anticipated. Plants can only absorb into their tissues fluids and gases, and 

 although they have the power to a limited extent of rendering soluble certain 

 substances, insoluble compounds as oxide and carbonate of copper are for the 

 most part harmless and inert. 



For many years the application of Paris green (arsenite of copper, insoluble) 

 has been in use for the destruction of the Colorado potato beetle. If the cop- 

 per of such became and remained easily soluble, thousands of acres would long 

 ere this have been rendered barren. 



To sum up, my contention is that the copper which reaches the ground from 

 properly conducted spraying is so minute in quantity and so insoluble in nature, 

 that no fear need be entertained of injury to growing vegetation. It certainly 

 seems to me that it would be very foolish to relinquish so potent a means of 

 preserving our orchards and vineyards and their fruit, before science or practice 

 proclaimed the true nature of such to be a curse rather than a blessing. 



Ottawa, Nov. loth, i8gi. Frank T. Shutt, 



Chemist of the Dominion Experimental Farms. 



APPLE MARKET IN BRITAIN. 



A cable from Wood, Ormerod & Co., Edinburgh, Scotland, gives the following quota- 

 tions, Baldwins, IBs, to 15s.; Greenings, 12s. 6d. to 13s. 6d.; Spies 12s. to 14s.; Various 

 colored, 128. to ISs. Expect an advance. 



