339 



ground where the saltpetre had been applied, and also 5 hills 

 where there had been no saltpetre, and weigh each parcel. The 

 potatoes on the ground where the saltpetre was applied, weighed 

 9 lbs., the other 4 lbs. ; this, it will be perceived, was the re- 

 sult of one year's application only. I am inclined to think 

 that its influence will be felt more or less the second, or even 

 the third and fourth years. 



A field containing two acres from which grass had been ta- 

 ken for 8 years, I had ploughed in the spring of 1838, once 

 only ; it was ploughed deep, and 90 rods were appropriated to 

 the growth of ruta-baga. The seed was sown upon the tops 

 of the furrows, without any manure in the drill, and the result 

 was, that I obtained 500 bushels of the article specified above; 

 the remainder of the field was sown to oats, but the crop was 

 mostly destroyed by the unexampled growth of hog weed. 

 This field had been wholly sustained by the application of 

 saltpetre upon its surface, previously to its being ploughed, ex- 

 cepting at the time of ploughing, when there was turned in a 

 small coat of manure." 



D. S. Haggerston, the intelligent and experienced manager 

 of J. P. Cushing's garden and farm at Watertown, has been 

 kind enough to favor me, at my request, with some practical 

 observations and experiments on the subject of manures, which 

 deserve attention, and are therefore subjoined. 



" I send you an account of experiments made on the farm of 

 J. P. Gushing, Esq., of the diff'erent composts used as manures, 

 and the apparent effects of each. 



Meadow muck or peat has been used in various ways, and 

 found so very beneficial, that two thirds of the manure used 

 on the farm is dug from the swamp. 



A compost for top-dressing mowing land is made from leached 

 barilla ashes from the soap-boilers' and meadow muck, in the 

 following manner. The muck is dug from the swamp, the last 

 part of August, or early in September, and lies one year on the 

 surface, after it is thrown out of the pit. It is then carted to a 

 convenient place to make the compost heaps, which are formed 



