94§ 
THE TROPICAL AGRICULTURIST. 
[May i, 1882- 
land than the American variety, the English Elm (Ulmus 
campestris) in dry situations than U. americana, and 
Salix alha than the American kinds. The trees of North- 
eastern Asia, Northern China, and Japan are as well 
suited, it seems, to the North Atlantic States of the 
Union as to our own climate. Of Rocky Mountain trees, 
the Blue Spruce — Picea pungens — better known as P. 
Menziesii, is a tree of rapid growth, great hardiness, 
and of a peculiarly charming blue-green colour. We 
cannot say as much of it here either as to colour or 
hardihood, for in some places it has been severely in- 
jured by recent winters. — Gardeners' Chroniele. 
ADULTERATIONS OF COCOA. 
Cocoa is a seed of a tree called Theobroma cacao, 
which is cultivated in Mexico, West Indies, South 
America, and various tropical parts. The tree is an 
evergreen, and grows about 20 feet in height. The 
leaves are dark green, and about 6 inches in length 
by 3 inches in breadth, the flowers are small and 
white. The fruit somewhat resembles a cucumber, 
and is about 6 inches in length and 4 inches in 
diameter, although some are much larger. These poda 
generally contain about 25 to 30 seeds, although 
some contain more. These seeds, after drying, roast- 
ing and winnowing from their husks, are broken into 
coarse fragments and known as cocoa-nibs. 
Cocoa, as a food, is highly nutritive, and will some- 
times nourish when all other things have been tried 
and failed ; but cocoa, as prepared direct from the 
nibs, by boiling, is apt to disagree with some jper- 
sons on account of the large quantity of fat it con- 
tains. This, in a great measure, was overcome by 
mixing starch and sugar with the cocoa in such 
proportions as to make a very palatable article ; but 
this was soon followed by adding the starch and 
sugar in snch very large proportions to a very small 
quantity of cocoa and red ochre that it was very 
difficult, except by analysis, to know what was 
soluble cocoa and what was a mixture of old sea 
biscuits, sugar, red ochre and cocoa husks. 
For the detection of adulteration of cocoa the 
microscope plays an important part, and in many 
cases a microscopical examination will be found suffici- 
ent for all ordinary purposes. For the examination 
a small quantity should be placed upon a slide and 
a little water added, and then examined with a £ 
inch o. g. , when the structure of the cocoa-bean will 
be plainly seen, also the presence or absence of 
starch; but all cocoas that thicken in the cup con-, 
tain starch. The sugar can be estimated either by 
standard solution ot copper, 01 by first mixiug a 
weighed quantity of the cocoa with water and filter- 
ing j the sugar will dissolve, and pas's through the 
filter, while the starch will remain behind, and the 
filtered portion can be evaporated and weighed. For 
the estimation of the starch, it should be converted 
into sugar by boiling it with a few drops of hydro- 
chloric acid. You may know when all the starch is 
converted into sugar by testing it with a little iodine ; 
the red ochre can be detected in the ash. The ash 
ot pure cocoa when thoroughly incinerated should be 
nearly white ; if red, it shows the presence of bole 
Armenian. The copper test is made in the following 
manner : — Dissolve 09 gr. of sulphate of copper in 276 
gr. of distilled water ; add to this 276 gr. of a 
saturated solution of tartrate of potash, then add 80 
gr. of sodic hydrate, previously dissolved in 1 ounce 
of distilled watt-r; shake well together, and place it 
in a vesbel holding 2,000 gr., graduated into 1,000 
equul parts, a, d till up with distilled water. Every 
2<>0 gr. of this will decompose 1 gr. of glucose. — 
Aljukkt Smith.— Oil and Drug News. 
SOME FACTS ABOUT CONIFERS. 
Economic Value. — The economic value of the Conifer* 
surpasses that of all other forest-trees together, supply- 
ing a larger proportion of timber used. The woods of 
the Fir, Pine, and Cedar are valuable for all purposes, 
and some of them are of immense durability. The 
money value of the Fir timber imported into Great 
Britain into 1879 from Scandinavia and Russia alone 
was about £5,000,000 sterling, the total value of the 
imported coniferous wood in this country being about 
£9,000,000 per annum. Most countries of Europe de- 
pend largely for fuel and timber upon their plantations 
of Fir and Pine. Even in our own country Pinus sylv- 
estris, which formerly spread over a great part of 
Scotland, has been a source of wealth to its owners. 
The forest of Rothiemurchus, between Cairngorm and 
the Spey, 16 miles in extent, produced, according to 
Sir T. D. Lauder, sometimes as much as £20,000 per 
annum in Pine timber. From the adjoining forest of 
Glenmore, sold by the Duke of Gordon for £10,000, 
were produced forty-one sail of ships of upwards of 
19,000 tons burthen.* The indigenous Scotch Fir is 
now, however, to a great extent superseded by the Larch. 
Between 1759 and 1830 the Dukes of Athol planted 
10,000 acres with Larch alone, and on then- Blah' and 
Dunkeld property the total number planted was 14,096,719, 
calculated at the time of planting to produce at the 
age of seventy years £6,500,000 as timber for naval 
purposes. An instance of indxrectly remunerative Fir 
planting is shown at Bournemouth, where some years 
ago plants of Pinus maritima were introduced in marshy 
land between Christchurch and Poole, which, spreading 
in all directions, partly by its own seed and by plant- 
ing, soon gave the country the appearance of an Amer- 
ican Pine barren. The shelter and presence of these 
trees has been found so beneficial to invalids that one 
of the largest watering-places on the south coast has 
sprung up with almost unexampled rapidity, and sites 
which were formerly worthless hive recently become 
extremely valuable. Similar plantations have been made 
elsewhere. M. Javal has planted 80,000 acres of the 
ban - en Landes of Gascony with seedlings of Pinus mari- 
tima. Others have planted lesser areas. In Madeira the 
same Pine has been introduced, and now covers all the 
southern slopes above 2,000 feet, the inhabitants being 
almost entirely dependent on it for fuel. 
In other parts of the world the Coniferse are of equal 
importance. The quantity of Deodars, for instance, used 
in India is immense. The Punjab Forest Administra- 
tion Reports show that between 1874-75 40,000 logs of 
Deodar, besides those of Pinus excelsea and other Coni- 
fers, were floated down the Punjab rivers. In 1870 over 
100,000 cubic feet of the timber of Araucaria Cunning- 
hami reached Sydney market per week, and about as 
much more was exported to Melbourne and elsewhere. 
The seeds of many of the Conifer® are edible, those 
of the Chilian Araucaria especially fonniug the staple 
diet of the Indians of Chile, and in Italy the seeds of 
the Stone Pine are made into cakes. The sweet and 
nutritious nuts of Pinus Sahiniana are great favourites 
with the Indians of North-West America, who collect 
vast quantities of the cones. A sugar exudation occurs 
from the bark of the Sugar Pine. The leaves of the 
Himalayan Yew are dried and used as tea, while the 
bark of P. sylvestris is formed, in years of scarcity, 
into bread- by the Norwegians. A species of Juniper 
(J. squamata) is used in India in the preparation of an 
intoxicating liquor and for making yeast, and in Europe 
the common Juniper berry is used for flavouring gin. 
A large number were formerly, and several are still, 
used in medicine, and the Larch for tanning. 
The value of the various gums and resinous and other 
productions of the Coniferaa is also large. The chief im- 
portations in 1879 were — of Kawrie gum 50,439 cwt., 
* Selby, Hist- Brit, Forest Trees, 1842, p. 401. 
