196 MANURING COFFEE. 
And if a normal stimulating manure is required, 53 lb. 
of ammonic sulphate is substituted for an equal quantity- 
deducted from calcic sulphate. It will be interesting to 
our readers to hear that M. Ville prefers to apply the 
lime in his manures in the shape of gypsum. He states:. 
“¢ Calcic sulphate is nothing more than unbirnt plaster 
of Paris, and is composed of sulphuric acid and lime. 
It is found in nature in large quantities in the form of 
hydrate :— 
per cent. 
Sulphuric acid... Nee ce ... 4651 
amie ie bik Wa lesa Le ers yA 9) 
Water ... .. 20°93 
Exposed to a temperature of 248° to 266° F., it loses 
its water and passes into the state of anhydrous sulph- 
ate, more commonly known as plaster of Pazis. In 
using calcic sulphate I prefer it in this state. It is worth, 
about $d per cwt. It can also be used in the form of 
raw gypsum, only in this case the proportion must be. 
increased one-fifth.” Of course gypsum is not likely to 
be obtained in Ceylon for less than many times 83d 
per cwt. But we suppose. ifsulphuric acid were avail- 
able, the lime from burnt coral could easily be converted. 
from a carbonate into a sulphate? So many things. 
are waiting to be done, when sulphuric acid is locally 
manufactured and cheaply as well as plentifully sup- 
plied. We could then for ourselves convert bones into 
calcic superphosphate, the most valuable ingredient 
(though not the most costly) in all manures. M. Ville 
expresses his intention to write a manual for the in- 
struction of cultivators in this process. Meantime M. 
Ville is of opinion that the price of calcic phosphates is 
more likely to fall than to rise, looking at the fact 
that they (bones apart) enter into the composition of 
all eruptive rocks. He alludes to the large deposits in 
Estremadura in Spain containing 70 to 80 per cent of 
calcic phosphate. In Canada, Sweden and France. 
there are also deposits. After noticing the process by 
which calcic phosphates are converted into superphos- 
phate, preferable generally on account of its superior 
solubility, M. Ville proceeds to notice exceptions im 
which bi- and tri-calcic phosphates are more beneficial, 
viz., newly cleared land and damp meadows. Our 
readers will notice that M. Ville does not apply nitrogen, 
in the form of oil cakes, so largely used in Ceylon. He, 
however, fully recognizes the value of such substances, 
tf entirely deprived gf the oil, which has no manurial 
value. lf cakes contain any oil he gives directions for 
extracting it by means of chloroform, or by carbon 
bisulphide, or the light petroleams or coal oils. He. 
writes : ‘‘ These cakes are, in fact, very rich in nitrogen, 
