I. AGEICULTURE AND RURAL ECONOMY. 323 



He cited several other instances where the same results fol- 

 lowed ; in one case where an apple orchard, planted on an 

 old orchard's site, which had never borne fruit, was made to 

 produce a good crop by the application of ashes. I J r. Amer- 

 ican Philosophical Society. 



EFFECT OF MANURE ON PLANTS. 



A communication, illustrated by diagrams, was presented 

 to the Horticultural Society of London in reference to the ef- 

 fect of manures upon plants in the experimental grounds at 

 Chiswick. As a general rule, plants in unmanured boxes 

 were less vigorous than in those manured ; and while purely 

 mineral manures had little effect upon the grasses, they pro- 

 duced a marked improvement in the case of the clovers. Ex- 

 periments with solutions of ammonia salts and with nitrate 

 of soda showed specific differences in the results in the case 

 of almost all the different species of plants, and it was found 

 that a plant affected favorably by one of these groups of 

 salts was influenced in quite the opposite manner by the 

 other. 5 A, 1870, T8. 



APPLICATION OF POTASH TO PLANTS. 



Professor Nobbe, of Tharand, has published the result of 

 certain experiments made by him upon potash as a nutrient 

 of plants, the method adopted being one to which we have 

 already referred, and known as the " water culture." The 

 plants experimented upon were buckwheat and rye, although 

 the conclusions arrived at had reference more particularly to 

 the former. The solutions used were divided into those in 

 which the potash was completely excluded, or in certain 

 cases replaced by bodies of similar chemical properties, and 

 into those in which potash is present, but in different chem- 

 ical combinations. The general conclusions reached were 

 that, in solutions free from potash, otherwise nutrient, the 

 plants vegetated as if in pure water. They were unable to 

 assimilate, and exhibited no increase in weight, for the reason 

 that without the co-operation of the potash in the chlorophyl 

 grains no starch was developed. The chloride of potassium 

 was found to be the most effective form of combination under 

 which the potash could be offered to the buckwheat plants; 

 next to this came the nitrate of potash. With sulphate or 



