152 
Superphosphate of Lime. 
manure depends on its being perfectly mixed, so that every 
particle of bone should be exposed to the action of the acid. In 
many cases 1 have no doubt this has not been sufficiently at- 
tended to, and the result has been either that more acid has been 
used than is really required, or that much of the advantageous 
effects has been lost. 
By the method which I have here recommended, and which I 
have adopted after many trials, the mixture can be readily and 
accurately manufactured, and with perfect safety to the at- 
tendants.* 
5. Effect of various quantities applied in combination or com- 
parison with common bones and other known manures. 
Mv own experience of the advantages of sulphated bones com- 
menced in the very dry summer of 1844. Wishing to try their 
effects, and thinking that it was highly desirable to apply them 
as a compost by means of the drill (though I had not heard of any 
instances in which they had been so used), I resolved to make the 
attempt. I intended to apply the bones at the rate of 3| bushels 
per acre, and half their weight of acid ; but from not making 
sufficient allowance for the dampness of the manure, it extended 
over a larger portion of land, so that little more than 2 bushels 
per acre were used with about 16 bushels of ashes. On the same 
day (in the early part of July) other portions of the field were 
drilled with bone-dust at the rate of 16 bushels per acre, and some 
parts with South American guano. The bones and acid swedes 
were the first to appear, and their tops grew most luxuriantly. 
The turnips suffered from not being hoed till they were too for- 
ward ; but the crop throughout the field (considering the late 
period of their being drilled, and other unfavourable circum- 
stances) was a very fair one, about 14 tons to the acre. The 
bones and acid portion was fully equal to the rest, and indeed 
somewhat better than where 16 bushels of bones had been ap- 
plied to the acre. 
Every alternate ridge was carted off, and the remaining half 
fed off by old ewes with no other food, with the exception of a 
little inferior hay. The field was then sown with dredge (a 
mixture of beans, barley, and peas), and the crop was a very excel- 
lent one; that where the vitriolized bones had been used was at the 
least fully equal to any portion of the field, and indeed somewhat 
superior to that dressed with bones alone. Thus it will be seen 
that the manure answers perfectly well so far as the second crop 
* In manufacturing a considerable quantity of the mixture to meet a 
large demand for the present season (1846), I have found much advantage 
from constructing various utensils of different shapes, so as to perfect the 
mixture without inconvenience to llie attendants, as well as from other 
improvements in the manipulative process.— Author. 
