Artificial Manures for Swedes. 15 



This manure, it will be observed, consists principally of 

 crystallized green vitriol and bi-sulphate and sulphate of soda. 

 These sulphates of soda are obtained at a cheap rate, as a refuse 

 in several chemical manufactories. Both the crystals of green 

 vitriol and Glauber salt or sulphate of soda contain much water 

 of crystallization ; hence the large amount of water (36 J per 

 cent.) in a tolerably dry substance. The economical manure has 

 a strongly acid taste and reaction, and might therefore be sup- 

 posed to contain a great quantity of soluble or acid phosphate of 

 lime ; but whilst it contains only about 7-10ths per cent of 

 ammonia, phosphoric acid is excluded entirely from its com- 

 position. We need not, therefore, feel astonished that it pro- 

 duced scarcely ariy effect upon swedes. 



The price at which the economical manure sold last season, 

 and is again sold this season, is 12/. per ton. Its constituents 

 can be furnished at about 31. a ton ; the manufacture of a manure 

 of the above composition thus might even pay well if sold at 

 5Z. per ton instead of 127. per ton, its actual price. 



Plot VI. Manured with 120 Ibs. of nut refuse, or at the rate of 8 cwts. 



64 Ibs. per acre. 

 Cost of manure 5s., or at the rate of 2Z. per acre. 



The swedes upon this plot had as healthy an appearance as 

 any of the experimental plots, and it was difficult to observe 

 any difference in the relative average size of the bulbs of this 

 plot and those of the next and the tenth plot. 



This refuse was the powdered cake of an oily nut, probably 

 cocoa-nut. It was submitted in my laboratory by my pupil, 

 Mr. Louch, to a partial analysis, who found in 100 parts 



Water 11-60 



Organic matters 79*12 



Inorganic matters (ash) 9*28 



100-00 



This quantity of organic matter on combustion gave in two 

 experiments 



1 Exp. 2 E*p. Average. 



Nitrogen 4'826 490 4'863 



In the 9 '2 8 of ash were found 



Earthy phosphates 4*12 



Phosphoric acid, combined with alkalies *13 



Sand and soluble silica 2*42 



Alkalies, magnesia, &c 2-61 



9-28 grs. 



It will be observed that this nut-cake manure contains a very 

 large amount of nitrogen, and also a quantity of phosphates and 

 alkalies which is by no means inconsiderable. It was sold in 



