March i, 1882.] 
THE TROPICAL AGRICULTURIST. 
775 
be in 
locality 
in eac 
in the 
be re 
and <• 
It if 
of the 
modific 
before 
their 
repea t 
What we are alif 
necessary by roast 
in the descriptioi 
of manures employ 
acid, or that 3 1 
per aere. We do 
produce any de: 
many who liavo 
to discover the 
acid in 
which tl 
districi 
future 
ulated 
our readers a i 
labour should tl 
on thou- own It 
upeo 
to these c 
if wo are 
per cent so 
bought be as gooi 
the experiments? I 
ions which wo now j 
I that so many shilli 
report. How are they 
pounds of phosphoric 
3cwt. of some super 
orth of 22 
ire is then 
o bo over- 
luch of a 
no difficulty in doing likewise; the dim 
como is when wo are told to use 
manure as shall contain a certain weight of some one 
constituent. 
explanatory of the first, is sometimes made, which 
states the actual amount of phosphate of lime (chemically 
termed monocalcium phosphate) which is soluble iii 
water, and its percentage is always lower than that 
of tbo tirst. One more entry (3) may be found, namely, 
the percentage of insoluble phosphate of lime, or that 
part of the original material which has escaped 
alteration during the manufacture. To calculate, then, 
tho amount per 100 lb. of the super of phosphoric acid 
contained iu either 1 or 3, it is only necessary to 
multiply the percentages by 0*46, in 2 tho amount is 
|Dhn(i by multiplying by 0*607. The products from 1 
and 2 will be the same, as tho two substances are 
identical, the lirst being a technical term, the second 
the chemical term. Care must therefore be taken that 
both figures aro not employed in the calculation. As 
an example, we quote the following analysis: — 
Per cent. 
1. "Soluble phosphate" (equal to bono earth 
made soluble) 21*84 
2. Soluble phosphate, moliocalciiim phosphate. . Hi-:!:) 
3. Insoluble phosphate : .. .. 6'56 
Multiplying the percentages of 1 and 3 by 0 - 46, wo 
And that 1 contains 10 lb, and 3 contains 2.J lb. of 
phosphoric acid, though not in the same state of 
combination. If 2 he multiplied by <Wi07, the same 
result is obtained us when 1 is multiplied by 0*46. 
Of course, if the manure be wholly insoluble, us in 
the case of bniies, there can then be no doubt as 
to which factor to employ. 
Nitrogenous manures being also hugely employed, 
either as sulphate of ammonia, nitrate of BOCU, or 
raw bonee, H is nnfmnnj ■" thou how it is ppMbn 
o translate a given number of pounds of nitrogen 
nto sulphate of ammonia, &c, or vice versd. Tho 
malyscs state, besides tho phosphate of lime, the 
lercentage of ammonia which can be obtained from 
ho bones. To calculate the amount of nitrogen to 
7hich this percentage is equivalent, divide by 1-214; 
ir, supposing that it is desired to know how much 
iure sulphate of ammonia will contain the same weight 
if ammonia, then the ammonia in tho bones must 
io multiplied by 3-88, and its equivalent in pure 
titrate of soda will also bo obtained by employing 
he multiplier 5. 
In tho same way we may calculate the quantities 
if guano which are equivalent to known weights of 
ulphato of ammonia, &c. The only other manure to 
sdiich wo need specially refer is kainit, which contains 
least 24 
Multiplication of tin 
0-44 gives tho amo 
aid of these figure! 
readers will bo able 
more thoroughly, th 
carried on for years 
sulphate of potash, 
percentage of the sulphate by 
it of potash present. By tho 
we hope that some of our 
to understand, and to appreciate 
experiments which have been 
past by such earnest workers 
as Messrs Lawes and Gilbert, and others. 
FOEESTRY IN MOUNTAIN DISTRICTS. 
(Field, 26th November 1881.) 
Whilst the legislation of this country is feeling its way 
towards some remedial measures in reference to the in- 
creasing injury arising from floods, it may interest our 
readers to learn that so far back as the years 18(50 aj>d 
1804 tho French Government passed laws in reference 
to the planting and turfing of mountain districts with 
tho view of preventing the formation of torrents. We 
aro indebted to M. P. Demontzey (who holds the im- 
portant position of Conservatcur des Forets) for this in- 
formation, together with a vast mass of details as to 
the carrying out of the necessary works. M. Demontzey 
is well qualified to bo the author of a practical treatise 
on the replanting and grassing of mountains, and the 
work is certified by the Ministers of Agriculture and 
Commerce. 
Tho French Government, having the advantage of a 
Forestry Department, are more alive to the necessities 
of assisting proprietors to make improvements. Wo 
proceed to give a brief outline of the objects sought 
and the results. Tho laws to which wo have referred 
have two branches — one of encouragement, the other of 
restriction. Tho former consists iu tho powers given to 
the State to stimulate proprietors) by grants of money 
and material, to replant and renew unproductive soils or 
exhausted pastures, of which the actual condition would 
contribute either to tho formation of new ton-cuts or 
the extension of existing ones. This measure is applic- 
able to all mountain regions. It is essentially prevent- 
ative in its action, having for its final aim the main- 
tenance and protection of the soil by a series of re- 
planting or rograssing, which the law has named optional, 
and which are thus useful to the general interest, as 
well as advantageous to proprietors. Tho means of co- 
ercion give the right to improve in tbo name of public 
utility similar works called obliijntorii, of which a pre- 
liminary inquiry has proved the imperious necessity. 
The one i> for pre\ cut ion, tho other for euro where the 
malady exists. 
The object of these two laws may be thus described. 
On ouo band, to prevent the formation of torrents by 
the consolidation of the soil on mountain surfaces; a 
result obtained by optional planting and tuning, ami 
even sometimes by obligatory turfing. <>n the other band, 
to suppress the effects of actual tonvnts by obligatory 
works of both kind*. Finally, to obtain and maintain 
by the results of the e two primary eu*ivts the regulation 
of torrential rivers and the protection of valleys below. 
The observation of scientific mm K-d to the cuuelu- 
