266 



071 Manures and on the Growth of Turnips. 



To be certain of the difference of the weight of the foliage of the 

 turnips manured with gUie-dross, and those manured with bones and 

 dung, I weighed the tops of turnips growing on 44 yards respectively ; 

 on bones and dung the tops weighed 11 lbs., on glue-dross 26 lbs. I 

 should likewise mention that owing to my farmer's mistake respect- 

 ing the length of the rows, I weighed, according to our first intention, 

 600 yards of each, and have made the respective calculations upon that 

 quantity. I think my weight per acre would have been greater if I had 

 left a foot instead of 9 i aches between the plants. 



I regret much not having used Poittevin's manure; for at 13 bushels 

 per acre, as tried by me last year, it has not carried through the crop 

 of barley. At harvest I set apart two plots of precisely the same di- 

 mensions in my barley-field, carried and thrashed the produce of each 

 carefully, and whilst the land manured with dung last year yielded 14j 

 bushels, that dressed with Poittevin gave but l6\ bushels, and about 

 one-third less straw. Double quantities, however, of this manure may 

 produce a very different result. 



Purple-top Swedes.— 1840. 

 Acreahle Produce from the 18 and 27 Inch Distance. 

 Common Manure. 



Tons. cwt. lbs. 



18 inches . . . 21 15 0 

 27 inches . . . 15 19 64 



In favour of 18-inch distance . , 5 15 48 



Glue-dross. 



1 8 inches . . .22 9 6 



27 inches . . . 16 1 47 



In favour of 18-inch distance . . 6 7 71 



Bones. 



27 inches . . . 20 5 89 



18 inches . . . 16 4 44 



In favour of 27-inch distance . . 4 145 



Since writing to you, I have had the pleasure of reading Professor 

 Liebig's work on ' Organic Chemistry,' and perceive that in treating of 

 the different kinds of manure, he thus mentions the glue-dross : " In 

 the manufactories of glue many hundred tons of a solution of phosphate 

 in muriatic acid are yearly thrown away as being useless. It would be 

 important to examine whether this solution might not be substituted 

 for bones — the free acid would combine with the alkalies in the soil, 

 especially with the lime, and a soluble salt would thus be produced, 

 which is known to possess a favourable action upon the growth of 

 plants. This salt, muriate of lime (or chloride of calcium), is one of 



