420 Abstract Report of Agricultural Discussions. 



to make in regard to tlie low-priced article containing the sulphate of 

 potash. He observed that it also contained 60 per cent, of chlorides ; 

 and these would keep it pretty well as moist as the chloride of 

 potassium itself would do. Of coiu'se the percentage of potash was 

 that which should determine our choice. 



Further, he concurred in what Dr. Voelcker had said respecting the 

 probable causes of a great many of the diseases of plants. The failure 

 of our crops, especially tm-nip and clover crops, was in many instances, 

 no doubt, materially due to the absence of that proper equilibrium in 

 the food supplied to them which was necessary for their healthy deve- 

 lopment. And with reference to the experiments that had been tried, 

 before we could rely absolutely upon any of tlicm, we ought to take 

 rather more precautions in satisfying ourselves that all the conditions 

 under which the experiments had been made were equal. For, first, 

 we had the character of the soil to consider : secondly, the nature 

 of the climate ; thirdly, the sort of crops to be grown ; and, fourthly, 

 the materials used. And rarely were all these conditions satisfactorily 

 fiUfillcd. 



Mr. Frere wished to take the opportunity of mentioning, for the 

 information of potato-growers, the one point that came out in the dry 

 season of last year, from his ovni small experiment. The exact record 

 of that experiment had unfortunately been lost, in consequence of the 

 death of his farm-manager ; but this point came out in a very marked 

 way — that the only plot, besides that maiiured with formyard dmig, 

 that could resist the di-ought at all, was the one which had received 

 a dressing of superphosphate, and probably also a similar di-essing of 

 those alkaline salts, salts of potash. Where potatoes were gromi on 

 a sandy soil, therefore, and farmyard manure ran short, he would 

 recommend a mixture of superphosphate and those crude potash-salts, 

 he should say, under correction of Professor Voelcker, at the rate of 

 four or five cwt. per acre of each. 



Dr. Voelcker was desirous of supplying an omission which he had 

 inadvertently made in the concluding portion of his lecture. He 

 recommended the follomng formula for experiment, with crude 

 potash-salts, upon light soils, for turnips, potatoes, and clover : — 1st, 

 use the salts alone at the rate of three cwt. per acre ; 2nd, apply three 

 cwt. of common salt per acre, in order to ascertain how much was due 

 to the common salt, and how much to the potash contained in the 

 German salts ; 3rd, use thi-ee cwt. of crude potash-salts, with three 

 cwt. of superphosi^hate ; 4th, use three cwt. of common salt and three 

 cwi;. of superphosphate. The reason he suggested the use of super- 

 phosphate in conjunction ^^-ith salts of potash was because these were 

 known to be very important materials, and also because the only trial 

 which last year gave him a good result upon clover was made with 

 a mixture of sulphate of potash and superphosphate. Indeed, the two 

 together — sulphate of potash and superphos^^hate — produced a very 

 material increase in the clover-crop. 



Colonel Challoner proposed a vote of thanks to Dr. Voelcker for 

 his very lucid and useful lecture. 



The Hon. A. Vernon, in seconding the motion, observed that not 



