EXPERIMENT STATION. • 61 



Home-made Superphosphate. 



Occasional inquiries are made at the Station with regard to the 

 method of preparing superphosphate of lime on the farm, and as 

 to the economy of its home manufacture. It is perfectly practica- 

 ble for a farmer to make a high grade and moderately fine article 

 without any considerable outlay for apparatus. The economy of 

 the manufacture depends on the prices which he has to pay for the 

 phosphatic raw material and oil of vitriol delivered on his premi- 

 ses. In general it is probably cheaper for him to buy his super- 

 phosphate ready made; but it occasionally happens that he can 

 find in his neighborhood small quantities of suitable material 

 offered at a low rate, being a waste product from some manufac- 

 turing establishment, which of itself is comparatively inert as a 

 fertilizer, but which can be economically treated with oil of vitriol 

 on the farm and so be made valuable. 



An instance of this kind has come to the notice of the Station 

 within the last year. A gentleman living near a factory where 

 iron was extensively worked found that each year a ton or two of 

 bone char was thrown away which he could get for about $8 per 

 ton. Bone char contains no nitrogen, but a high percentage of 

 phosjjhate of lime in an inert condition. Applied directly to land 

 little or no immediate effect was to be expected. 



It was suggested that he try the experiment of treating this 

 char with oil of vitriol, which he could buy for 1^ cts. per lb. by 

 the carboy. The j^rocess employed was as follows : A vat was 

 constructed by laying boards closely together on level ground, 

 and putting up sides eight or ten inches high, after the style of a 

 moi-tar bed. 500 lbs. of bone char were put in the vat, and spread 

 somewhat, with a slight depression in the middle of the pile where 

 the water and acid were afterwards poured. 15 gallons of water 

 were measured into a barrel and 300 lbs. of the acid were weighed 

 off" into a crockery vessel. It could have been weighed into wood 

 but would have charred it somewhat. — The greatest cai-e is neces- 

 sary in pouring the acid fi-om the carboy. The receiving vessel 

 should be held close to the neck of the carboy to prevent spatter- 

 ing as much as possible, and the eyes kept averted ; for the acid 

 destroys the clothing and burns the skin very quickly when it falls 

 on it. A drop on the skin should be immediately wiped off" with 

 a cloth and the place well washed. — The water was then poured 

 rather slowly over the bone char and mixed with a hoe till the 



