THE TROPICAL AGRICULTURIST. [February i, r88 2 . 
In the conservation of green food, maize, clover, &c, 
in trenches, a fermentation ensues, of which the seat 
is the vegetable cell : carbonic acid ; alcohol, and acetic 
acid are produced at the expense of the immediate prin- 
ciples contained in the forage ; over 2 per cent of car- 
bonic acid in the case of maize, and nearly 1J per cent 
for clover, is given off during fermentation : if a part 
of the nutritive principles be lost, the remainder are 
made more utilizable : also ; the fatty matters are in- 
creased during the fermentation. 
M. Deherain has repeated de Saussure's and Coren 
Binder's experiments, that of testing the influence of 
carbonic acid on vegetation. But little of this acid is 
contained in the atmosphere : 10,000 quarts of air contain- 
ing not more than 3 or 4 : the professor placed hari- 
cots, colza, and tobacco plants, under bell glasses, so 
as to exclude all communication with external air : then 
pure carbonic acid, in measured daily quantities, was 
introduced. The beans and colza showed any excess of 
acid to be unnecessary; but the tobacco leaves became 
very plethoric, owing to immense deposit of starch- 
matter in the leaves. The experiment was controlled 
by kindred plants also placed under bell glasses, but 
supplied with common air. The tobacco leaves assimi- 
lated more carbon than was supplied by the intro- 
duced acid. From whence did it come? From the 
disengaged oxygen, acting on the carbon, in the soil 
contained in the pots, and thus producing additional car- 
bonic acid. 
Since 1847, Belgium has adopted the plan, and with 
best results, of decorating artizans and laborers with a 
medal, to be suspended from the coat buttonhole. The 
idea is about being introduced in France. Indeed hum- 
ble distinctions would be appreciated, more particularly, 
if accompanied by a slender pension, or a donation to 
be paid at fixed intervals. 
THE "TEOPICAL AGRICULTURIST " : NEW 
PRODUCTS FROM SOUTH AMERICA, &c. 
Mr, A. Scott Blacklaw writes : — " I received your 
Directory from Mr. Westland, Aberdeen. The book 
has risen to a respectable size, and the contents of the 
volume have increased in value to the planter in an 
equal proportion. 
" The Tropical Agriculturist I have only seen the 
first number of, and I am waiting for the remaining 
numbers. I hope you have tbem. The value of it 
cannot be calculated. The tropical farmer can now 
have the information necessary for enabling him to 
experiment on any plant that the climate he lives in 
is capable of producing. It will be so convenient to 
file and carry about after it is riled. I notice Ceylon 
is well supplied with nearly everything that can be 
grown at a profit : Liberian coffee, cocoa, tea, and 
cinchona. Some of the finer qualities of the last- 
named plant would no doubt be acceptable. I had 
several conversations with native merchants in Para 
about seeds of the valuable kinds grown in some of 
the Bolivian forests. I came to the conclusion that 
the only way of procuring these was to go among 
the Indians one's-self, and even then, they were diffi- 
cult to get, owing to the Indians setting such a high 
value on those trees. 
"The people of Para and those along the banks of 
the Amazon are not free from jealousies, and are un- 
willing that other countries may be put in the way of 
supplying the world with products of which up till 
now they have had a monopoly. The wax-producing 
palm and the Vegetable ivory palm could both the 
cultivated in Ceylon. I expect some seeds of the' 
former, and, when I get a chance, I '11 send you some 
candles made froni the wax as it comes from the tree. 
The ivory plant will be difficult to get, as it grows 
in the Porevts I n up the valley — the river Purus, — in 
Peru and Ecuador. None of these can ever take the' 
place of coffee, but they will be convenient to cultivate 
as an auxiliary, and as something that can keep coolies 
in profitable employment during the idle season. 
"I was very much interested in reading the letters 
of your chief on his voyage home from Australia, par- 
ticularly that part on Queensland. I am glad to see 
he has got back again in sound health." 
Mr. A. S. Burnett (a well-known Uva planter) 
writes :— 
" I shall return to Ceylon again probably early in 1882, 
and write to aek you to keep for me copies of Tlie 
Tropical Agriculturist. There is no publication extant, 
which really occupies the special field you have entered 
on, and whether in the East Indies, or the West, its 
pages will be carefully perused by all who feei an 
interest in tropical cultivation. By none, perhaps, will 
it be more gladly welcomed than by old colonials." 
PRACTICAL PLANTING NOTES ON TOPICS 
OF THE DAY IN CEYLON: 
MR. PAESONS' "PERFECT CURE 71 FOR GRUB :— SUCCESS- 
FUL EXPERIMENTS ; — GREEN GLASS FOR NURSERY 
FRAME (NOTHING LIKE ' GREEN SPECTACLES '); — 
THE CINCHONA MARKET : CUPREA BARK AND 
THE PRICE OF QUININE. 
Agrapatana, 27th Dec. 1881. 
You will be interested to barn that Mr. Parsons' 
method or invention for destroying grub has now 
been pronounced a complete success. It is a fait 
accompli of which the importance can hardly be over- 
estimated. 
Those who have had flourishing fields of coffee re- 
duced to so deplorable a condition that it is hard 
to believe they will not die |out altogether will welcome 
these tidings. 
I, in common with many others, was sceptical at 
first, but conviction has, for some time past, been 
forced upon me, till the other day I witnessed, in 
company with Messrs. Fairlie and Campbell, an absol- 
ute proof of the efficacy of this plan. 
Mr. Parsons in our presence removed some sacks, 
which had been laid down in the prescribed manner 
a little more than a week, and under them we saw 
a great number of grub of all sizes comfortably curled 
up in small round holes on the surface of the ground, 
On the area, which had been covered by one sack 
(cut open of course), we counted 56 grub. These were 
removed and then we dug carefully over the whole 
space the bag had covered, to eighteen inches deep, 
with the result after careful search of finding six more 
grub, who seemed on their way up. It is not taking 
too much for granted to suppose that in four days more 
tbey would have joined " their cousins and aunts." 
It seems certain now that Mr. Parsons has found 
a means of attracting all the grub to the surface 
of the soil, where they can be at once captured and 
destroyed. 
The main question : How much does it cost per 
acre ? he is prepared to answer in a satisfactory manner. 
Old bags are cheap, and, when used on one field, can 
be removed to the next, and as ten days does the 
business, it follows that 20 acres of bag surface will 
cure a 200 acre estate of grub in under four months. 
A visitor, who watched us testing the method with 
great interest, made the excellent suggestion that old sail 
cloth would be the very thiny. Manure bags rot very 
soon, and would never last four months in tke rain and 
eun; also each bag would have to be taken up separately. 
Now a bolt of sail cloth would lie between the lines 
of coffee for ten days, and then might be rolled up, 
turned round, and unrolled along the next 53 yards, 
Which, I am told, is its length. The only expense would 
