Ft-BRUARY I, 1892.] 
TH& TROPJCA'L AOniOULTUR?Sr. 
587 
plant becomes abnormally yellow, a characteristic 
sign of some form of disease, or the presence of 
some animal with which it has to struggle for 
life. On examination now the plant is found to 
be the victim of the coffee-scale. The berries pro- 
duce by such plants, if produced at all, are small, 
few and worthless. A noticeable thing in connection 
with the presence of the " scale insect " is that 
attacked plants and fruit mature much earlier 
than sound plants, but, as stated, the fruit is 
worthless. Nearly fifty per cent, of their crops 
have been lost by tlie planters through the 
ravages of this insect. 
As for remedy M. Vendre'l recommends the use 
of nitrates as manure for the soil, but he says 
nothing as to means for destroying the insect 
itself. In America an emulsion of kerosine oil 
has be^n found very efficacious in cases of some 
the " scale-insets." — /faiii/nnit 't'iiiieti. 
THE liMPROVEME^"^ OF TKEP:S. 
It can hardly be doubted that trees 
whether grown for timber or for ornament, can be 
improved by methods similar to those which have 
been used for the development of our modern 
fruits and vegetables, and that the time must come 
when the same attention will be paid by scientific for- 
esters to the improvement of races of timber-trees 
as is now i aid to the improvement of plants of 
far less importance to the human race. 
There are certain individuals of every species 
of plants which, for some reason or other, grow 
more vigorously than others or possess other exceji- 
tional qualities. Tliis fact has been taken advan- 
tage of to establish new races of garden-plants, 
but in the case of trees it has been too generally 
ovoiiooked, and sufficient attention has never been 
paid to the selection of the seed-bearing parents, the 
mothers of future forests. The whole question of the 
improvement of trees, whetlieras producers of timber 
or merely as ornaments of gardens and parks, is 
still before us. Humbler plants often gain hardiness 
by the mingling of the blood of allied species, and 
wliat little has been learned of the few natural 
hybrid trees known to exist shows plainly that 
it is within the bounds of possibility to produce 
trees artificially by hybridization which may possess 
certain qualities to a greater degree tlian either 
of their parents. Then tliere is the whole question 
of the relation of the stock to tlie graft as applied to the 
liroduction of timber-trees to be investigated. It is 
known that certain trees, when it is desirable 
to produce them under certain conditions, grow 
mijch more rapidly and vigorously, whi'e young at 
least, if they are grafted, than they do on their 
own roots ; but time and careful observations are 
needed to determine what results, from economical 
points of view, will finally be obtained by such a 
method of propagation. 
All such questions as these are matters which 
must one dn.y occupy the attention of scientific 
forpsters, and which can only be solved at well 
Cituipiicd forest-stations, which all governments, 
following tho example of Germany, can wisely 
establish ; for without the stability which govern- 
ments alone can give, scientific observations, de- 
nuxnding a longer period than the life of one 
generation of men, are apt to be barren of_ 
useful - fruit. 
Such thoughts naturally lead us to consider 
whether it is not possible to increase the number 
of ornamental trees to be grown in any particular 
region and the beauty of individuals by the appli- 
cation of the same rules of selection of seed from 
exceptionally line individuals as we now employ in 
producing cabbages or radishes. This seems such 
an evident pro))osition that it requires no argument 
to sujiport it; and yet how few persons who raise 
trees from seeds pay the sliglitest attention to the 
character or health of (he individual which supplies 
^lieui. i'"or tho ordinary collector of tree-seeds in 
jlie nursery or the forest a seed is a seed, and 
^he fact ia iguoi'ed m t'orgotteu (hat the couati- 
tutional weakness of an individual jjlant can be 
transmitted through its seed. Neglect to properly 
select the seed-parent is doubtless the cause why 
many nursery-grown trees fail before their time, 
and why seedlings raised from trees subjected in 
cultivation to more or less unnatural conditions are 
less desirable than those raised from individuals 
growing spontaneously under the most favorable 
natural conditions. — Crankit and Forcil. 
EXAMINATION OF OIL OF CASSIA.* 
BY H. GII/BEBT. 
It is pointed out that oils of cassia and cinnamon 
may be highly adulterated with resin oils and still 
pass the tests of the Gennan Pharmacopoeia. With 
nitiic acid, sp. gr. 1'45 at or with I'oO acid at 
0°, both the pure and impure oils give crystals 
without development of heat ; however, with the I'oO 
acid at 15° both react violently, with development 
of heat and without the formation of crystals ; there- 
fore, the P. G. test, as neither the sp. gr. nor the 
temperature of the acid is stated, may lead to the 
condemnation of a pure oil and rice veisa. By de- 
termining the " acid number," the adulteration can 
be detected, as the following numbers show : — 
Acid numbers. 
Genuine oil of cassia (with 6 per cent, 
non-volatile residue). . . . . . . i;-) 
Genuine oil of cassia after 40 hours' 
aeration . . . . . . . . . . 13 
Genuine Ceylon oil of cinnamon (2 per 
cent, residue) .. .. .. .. 9 
Genuine Ceylon oil of cinnamon (2J per 
cent, residue) . . . . . . . . 10 
Adulterated oil of cassia (28 per cent, 
residue^ . . . . . . ... . , 47 
Adulterated oil of cassia (prepared from 
pure oil of cassia by intermixing 20 per 
cent, of colophony) . . . . . . 40 
Colophony, sp. gr. 1-08 lijO 
— Pharmaceufical Journal. 
ECHOES OF SCIENCE. 
Dr. Paul Gibier, director of the New York 
Pasteur Institute, has issued his report for the six 
months from February to August of this year. Of 
415 patients who applied for treatment, no fewer 
than 345 were found to be suffering from needless 
alarm, as the dogs which had bitten them were not 
mad. The remaining 70 cases were put under the 
Pasteur treatment, as the bites were really due to 
hydrophobic animals. Only one death took place. 
That of a child five years old, who had been bitten 
in nineteen places by a mad dog. Three other 
persons, namely two sisters of the child and a man, 
who had been bitten by the same dog, were also 
treated, and are now alive and well. 
Peat promises to become a very useful article. 
In a recent number of the Haiidrls Mu.'ician Dr. 
Leo Pribyl states that the Germans and Swedes are 
utilising their peat bogs in the manufacture of ■ 
naphtlia, tar, solar oil, paraffin, acetic acid, and gas, 
Moreover, the peat yelds an elastic fibre which, 
freed from dust, is employed for weaving into carpets. 
Good peat also furnishes a cellulose which is valu- 
able to paper makers. Besides serving as a whole- 
some litter for live stock, it is also used to preserve 
perishable goods. Meat and fish are now packed in 
peat litter for transpot between Trieste and Copen- 
hagen. Here is a matter for the considei'ation of 
Irish landowners, and peasant proprietors as well. 
Tlie Franco-American Cellulose Manufacturing 
Company, of Philadelphia, have a process for nuiking 
coconut cellulose which absorbs eiglit times its ^yeight 
of water. It is intended for use in lining vessels, 
and it is difficult to make a hole through it, 
The Journal of the Camera Club for December con- 
tains a paper by Mr. G. L. Addenbrooke, on theadvau- 
* Clicin. /dt., xiii., 1406-1107. Reprinted h QUI »eU 
Jouni, Qlicm, fs'oc, April, 
