458 
THE TROPICAL AGRICULTURIST. [January i, 1889. 
o 
placed under all sorts of circumstances considered t _ 
be favourable. Meantime, the United States Depart, 
ment of Agriculture has been most active in en 
deavouring to find a remedy, and some degree of 
success was attained when the orchardists employed 
certain insecticides, applied by means of the cyclone 
nozzle, which has been found so useful in this colony. 
But this was found to be very expensive to spray twice 
at least every season, and the spraying only killed the 
insects then upon the trees, and, of course, gave the 
plants no immunity from attack by fresh hurdes bred 
upon other plants and trees. Another, and a most 
dangerous remedy (even in the hands of experts), 
was found to be effectual for a time. The tree to 
be treated was covered with a gas-proof tent ; a portion 
of cyanide of potassium was plaoed in a vessel, and 
sulphuric acid poured on it. This produced a highly 
poisonous gas, or fume, immediately fatal to all 
animal life. This plan is universally condemned on 
account of its dangerous nature. 
The success of Mr. Crawford's experiment with 
the giant coccid put it into the minds of the United 
States Commissioners for Agriculture to send over a 
special delegate to Australia, as before said, with 
instructions additionally to endeavour to forward the 
parasite of the Icerya Purchasii to California. He 
has already visited New Zealand and New South Wales. 
In the latter colony he found two or three specimens 
of the Monophltebus, but was not fortunate enough 
to get the parasite on the Icerya. On Wednesday 
morning, October 3, however, he was shown some 
orange-trees owned by Mr. John Trewenack, Kent-ter- 
race, Norwood, upon which a few Icerya exist, and 
he was delighted to find no less than nine chrysalides 
of the fly in the body of the first Icerya examined. 
Two or three more were dissected, and specimens 
in all stages were found. Mr. Kcebele will at once 
make arrangements for sending as many specimens 
to California as can be obtained, and will follow up 
by fresh consignments in order that by some means 
the parasite may be introduced to the infected Cali- 
fornia orange orchards. That the enterprise may 
prove successful will, we are sure, be the earnest wish 
of all South Australian colonists. — Adelaide Observer. 
THE KISE AND POWER OF CAFFEINE. 
We have now before us the first fruits of the recent 
successful application to Government for the right 
to use " denatured " tea, duty free, for munufacturing 
purposes, iu the form of a very fine specimen of the 
alkaloid caffeine, prepared, from the material named, 
during the present month, under the new conditions, 
says the British and Colonial Druggist. The compound 
is superior in appearance to most of the imported 
brands, and is in the form of pure, white silky 
acicular crystals, resembling when in bulk, quinine, 
and possessing like that principle, though in a less 
degree, a bitter taste. As the subject of the prepar- 
ation of caffeine in England from damaged tea, and 
the consequent probable impetus to the therapeutical 
use of the alkiloid, have attracted considerable 
attention recently, both in medical, pharmaceutical, 
and general circles, we propose to follow our sketch 
of the agitation, with a summary of the present 
state of our knowledge as regards the chemistry and 
therapeutics of caffeine itself. 
The alkaloid caffeine, which is identical, chemically 
and physiologically with theine and with guaraniue, 
is remarkable in containing more nitrogen in its 
molocule than any other known alkaloid except 
theobromine, being represented empirically by the 
formula O^H^N^Oj. Concsring its constitution 
— a factor of very considerable theoretical and 
some practical interest in the case of all such 
bodies — two theories have been advanced; one by 
MedicuK, in 1875, and the other by Emil Fischer, 
in 1882. That of the Jatter investigator accords 
b«*t with the naturo of the decomposition products 
of the principle, and is graphically exhibited as 
follows 
Me. N — OH 
I II 
O O.NCH 3 
^>CO 
Me. N — C=N. 
Caffeine may be prepared from tea by one of at 
least three processes, viz., (1) by exhausting with boil- 
ing water, removing tannin with lead subacetate, 
and excess of -the latter with sulphuretted hydrogen 
evaporating and crystalizing ; (2) by filtering an 
aqueous decoction, evaporating to a syrup, mixing 
with slacked lime, and extracting with chloroform ; or 
(3) by evaporating tbe filtered decoction with oxide 
of lead, adding carbonate of potassium to the syrupy 
product, and extracting with alcohol. 
The pure alkaloid is only slightly soluble in water 
(1.35 bart in 100 at 60° F), less in alcohol, and still 
less in either (0-044 parts in 100 at 60 s F.). It is most 
soluble in chloroform, a hundred parts of which, at 
the normal temperature, take up 13 parts of 
caffeine. 
With regard to its physiological properties, Dr. 
Julius Lehmann carried out a series of experiments 
and published the results in 1853. He chiefly directed 
his attention to the influence of the principle upon 
the functions of the kidneys, which his investigations 
showed were intensified in a marked degree by the 
administration of coffee or of caffeine. After a 
number of tabular statements of the effects of coffee 
drinking upon the quantity of the urine and the pro- 
portion of its constituents, he says: — 
The influence upon the organism of daily 4 grain 
doses caffeine was, save an increased activity of the 
heart, not observable. Later, therefore, I gave G. M. 
(one of his provers) 8 grains daily, which induced a 
more frequent pulse, strong action of the heart, 
tremors and continual desire to urinate, though only 
small quantities of urine could be passed. At the 
same time the imagination was much excited, aud 
subsequently confusion of thought, visions and especi- 
ally a peculiar intoxication followed, succeeded by a 
profound sleep. 
Lehmann also concluded that caffeine exerted a 
retarding influence upon tissue change. Guhler, 
Shapter, Leech and others also proved it to act 
promptly as a diuretic, simultaneously reducing the 
pulse rate. Its effects upon this organ are ascribed 
to a direct action upon the nervous system thereof. 
In its physiologioal influence, caffeine seems to 
resemble alcohol more than any drug, as it directly 
stimulates the whole nervous, muscular and vascular 
systems ; yet it is a curious phenomenon that it 
prevents and moderates alcoholic intoxication, so that 
not only can more wine or spirits, etc., be imbibed, 
without symptons of poisoning, if coffee or any liquid 
containing caffeine be taken with them, but a 
strong dose of the same alkaloid will entirely avert or 
moderate an approaching condition of alcoholism. 
These results are valuable and noteworthy in that 
they were obtained by observation of the influence of 
the principle upon perfectly healthy and robust 
organisms, and not upon those more or less abnormal 
from the touch of disease. But from the clinical 
investigations already made, though not in very great 
numbers, caffeine would seem destined to play an 
important part in the relief of suffering and in the 
saving of life. It nas proved an efficient remedy 
in certain dropsical conditions associated with affections 
of the heart. Milliken, Brakeuridge, Huchard and 
others relate instances in which it has rescued 
patients from the jaws of a threatening and imminent 
death by its direct stimulant effect upon those won- 
derful ganglia which act as generating cells of nerve 
force for the supply of motive power to the heart. In 
atonic dyspepsia, in melancholia, and in other 
nervous affections associated with the conditions of 
our much belauded nineteenth century civilization, 
caffeine has proved a useful remedy, and in it the 
vast increasing army of those who " coin their 
brains into gold," often at a rate which the recupe- 
rative power of nature vainly strives to compensate, 
