96 



Mr. Dove on Experiments with Manures on Potatoes. 



dark green leaf, till subsequently nipped by tlie frost The pota- 

 toes from them were very large — some of them weighing upwards 

 of 1 lb., and several of the shaws producing upwards of 4 lbs. of 

 potatoes. All the lots wore of first rate quality. The potatoes grown 

 with the guano were a peculiarly richly flavoured dry mealy potatoe ; 

 the potatoes from the sulphate of ammonia a fine dry mealy potatoe ; 

 the potatoes from the bone-dust similar; and those from the soot 

 very good, but if any thing, inferior to the other two. 



In addition to the foregoing, I tried in the same field, and to the 

 same extent of ground, that is, 42| falls, potatoes, with soot, guano, 

 bone-dust, sulphate of ammonia, and farm-yard manure, separately. 

 The following table shows the weight of manure, cost, and produce, 

 per acre, Scots measure : — 



The potatoes from the guano and bone-dust were small, and had a 

 weak shaw ; those from the soot and sulphate of ammonia possessed 

 a fresh, strong, healthy shaw, and were of ordinary size. The failures 

 were in the same proportion as in the experiments with the mixture 

 of dung ; but there were no failures when the potatoes were planted 

 with farm-yard manure alone ; the quality of the potatoes from the 

 guano and farm-yard manure was good ; the quality from the soot, 

 ammonia, and bone-dust bad. The failures in the seed in these 

 experiments were not made up. The subsoil where the last five lots 

 were planted, was of an open sandy nature, and the upper soil deeper 

 than where the first four lots were planted. 



I^ote. — In the experiments detailed in the two preceding, and in the 

 following papers, the results are so varied, probably from the nature of 

 the season, that the conclusions to be deduced are not important. They 

 seem to favour the idea, however, that saline substances, as they have 

 been applied in these experiments, are not capable of superseding 

 farm manure or night soil altogether — inasmuch as the crop for the first 

 year appears generally to be more prolific when the latter is also pre- 

 sent. It remains, however, to be determined if the influence of these 

 manures is of a more permanent nature than that of farm manure — 

 and the promised continuation of experiments of Mr. John Wilson, by 

 whose desire Mr. M'Lintock's trials were made, will undoubtedly throw 

 light on this subject. — R. D. T. 



