On Stipcrjy/iosphate of Lime. 
325 
answeretl his expectations. Such is the simple liistory of this 
great discovery. 
Hitherto, as I said, the mi.\ture has been applied as a liquid 
manure, diffused soinetmies in fifty times its bulk of water; and 
it has been prepared in vessels troublesome to procure and liable 
to be injured by the acid. Availing myself, however, of a sug- 
gestion for dispensing even with these, I formed a flat heap of 
dry mould about ten feet across, the surface of which was scooped 
into a hollow basin, capable of holding 20 bushels of ground 
fresh bones. A little water was poured on, but I have since 
omitted the water. Sulphuric acid, to the amount of about half 
the weight of the bones, was gradually poured into this basin. 
They soon begin to heat, seething violently, and sending out a 
great deal of sti^am, with a peculiarly offensive stench ; presently 
the whole mixture wears the appearance of boiling blood, and 
swells so much from the escape of gas, that the \vorkmen stirring 
it with their hoes must take great care to prevent it from bursting 
over the sides of the earthen basin. In a short time, however, 
the cauldron becomes quiet ; and the bones disappear altogether, 
except a few fragments : so that the heap may be shovelled 
together, and might be drilled on the same day, but this would 
not be advisable, as some small lumps still half liquid remain in 
the compost. On the first occasion the earth and dissolved bones 
were left mixed together ; and though perfectly cool when so left, 
I learned, on returning, alter si's v. eeks' absence, that a second heat- 
ing had soon taken place, and found that the heap was hot still. 
The ofiensive smell was gone, aud was replaced by the musky 
odour of rotten dung. I mention this cir cumstance because 1 am 
anxious to draw" to it the attention of chemists. This second fer- 
mentation may be that of the animal matter contained in the 
bones, and may bring out its ammonia ; if so, it will be a question 
whether it be desirable thus to give time for the formation of 
ammonia before the manure is applied ; or whether it be better 
to drill the compost at once, allowing the ammonia to be pro- 
duced under ground, and so be supplied to the young plant more 
gradually. 
The compost thus made was tried in July on some light land 
very much exhausted, and naturally unkind for the growth of 
turnips. The trial ground was about 2 acres. On one part the 
compost of bones and acid was drilled at the rate of 4^ bushels 
of bones to the acre ; on another part, bones at the raie of 20 
bushels an acre ; and I added, on a third part, a manure (pur- 
chased from Mr. Fothergill, under the name of Superphosphate 
of lime) at the rate of 2 cwt. 
The bones and acid took the lead of the bones, arid kept it 
throughout. I am bound to add that the superphosphate prepared 
