THE TROPICAL AGRICULTURIST. [September r, 1887. 
practical men. Only Portland cement has received 
anything like scientific notice, and a few experiments 
upon waterproof, heat-resisting, and other cements 
vould show which cements are the best to use under 
certain circumstanctB. — Van Nost rands' Magazine. 
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ARTIFICIAL QUININE. 
The startling announcement that a medical man 
had succeeded in producing quinine artificially has 
naturally given rise to much uneasiness in the drug 
market. Such a discovery would several years ago 
have been hailed with enthusiasm, but just at present 
the merchants are desirous that chemists who work 
at the synthesis of quinine should take a very long 
holiday. At the London docks there lies an over- 
whelming stock of cinchona bark ; in our colonies 
immense sums of money have been invested in cin- 
chona plantations, and quinine is fast becoming a 
byword in Mincing Lane for whatsoever is uncertain 
and unprofitable. We have cried long lor cheap 
quinine; now we have it, and many wish it ti> be 
dearer, and watch weelt after week for the smallest, 
sign of au advance, as though the present low prices 
were a calamity. We take it that no one who has 
watched the great advance in our knowledge of the 
compjsitiun of some alkaloids, and of bodies closely 
al.ied to alkaloids generally, will dispute for a moment 
that artificial quinine will yet be produced. Tne 
manufacture of salicylic acid from carbolic acid by 
Kolbe is a most noteworthy achievement of science : 
and the synthetical preparation of indigo is of itself 
a proof that chemists are competent to bridge the 
gap between inorganic and organic bodies. It is little 
more than four years ago since M. Maumeuo, a French 
chemist, announced that by the discovery of H 2 N, 
or amidogen, he had succeeded in building up quinine, 
and actually deposited a packet of the supposed al- 
kaloid with the president of the Institute of France, 
while he had the physiological effects investigated. 
But nothing came of that, although the discoverer 
tiad determined the physical and chemical characcers 
< i the synthetic body to be the same as those of 
the natural one. Occasionally there have been scares 
similar to that of this week. When chinoline was 
introduced a few years ago as an antipyretic, and 
the attention of pharmacists was thus forcibly drawn 
to the relation between eninoliue and quinine, it was 
for a short time considered that we were on the 
eve of the important discovery. Closely following 
chinoline were several new bodies, such as kairine, 
which have served to keep alive the feeling that 
tne days of natural quinine are numbered. But these 
circumstances, from a chemical point of view, are 
trivial in comparison to the great advance which 
has been made in our knowledge of the decomposition 
p o mcts of alkaloius. It is in this direction that it 
is hoped to arrive at workab e synthetical methods. 
Altnough it is perfectly well known that alkaloids' 
aro derivatives of amnion a, there is no known law 
which ill enable us to represent such a complex 
f 01 inula as that of quinine (C2oH 2 ,N,0 2 ) in typical 
and c .nstitutioual order. Possinly in the molecule 
containing so many atoms of carbon, hydrogen, and 
the rest, Uiese are asso. lated in groups al >ng with 
a nucleus, an I the tendency of recent research is to 
show that it is so. That research has also shown 
that all alkaloids, with a few exceptions, are asso- 
ciated with one of two g oups of organic bodies — 
viz., the pyridine and ehiiiolme bases, which are now 
convenieuily ranked amongst alkaloids. These bases 
can be synthetic .illy prepared; many of them are 
found in coal tar, and they can be made cheaply on 
a manufacturing scale. It is assumed by chemists 
that they represent the rational starting-points for 
the ar.ificial manufacture of alkaloids. It is here 
that the value of decomposition experiments becomes 
apparent'. Obviously, if the products of decomposition 
bo known, the putting together of these products 
in proper proportion will result in the original body, 
lor example, Laden bfirg succeede I in ittaking atropine 
irfcif billy by combining tropine and tropic acid, the 
1 wo decomposition products of atropine; and since 
then tropic acid has been synthetically prepared 
The object of the investigator is to start with the 
lowest or the intermediate derivatives of the alkaloid 
which he desires to prepare, and already we have 
several bodies which have been formed on this basis. 
The formation of codeine from morphiue referred to 
in our last issue is a good example of a very simple pro- 
cess. The formation of caffeine from guanine is more 
complex. Guanine is obtained from guano, and has the 
formula C^H^N^O; by treating it with nitrous acid 
xanthine (C. 5 H 4 N 4 OJ is obtained, and this again, by pro- 
per treatment, yields theobromine ( J T H 6 N 4 0. 2 ). Caffeine 
is methyl-theobromiue (just as codeine is methyl- 
morphine), and by acting upon theobromine with 
methyl iodide, the methyl radicle takes the place of 
a hydrogen atom, and caffeine, C ; H, (CH 3 ) H 4 0- is 
formed. In this case a naturally formed body is 
started with, so that even this excelleut example of 
synthesis is not perfect synthesis ; but we have the 
desired illustration in Lidenburg's process for the 
preparation of piporidine, in which trimethylenecyanide 
is started with. This body can be built up from its 
elements, and is readily converted into pentamethylene 
diamiue, the hydrochloride of which splits up into 
ammonia and piperidine hydrochloride on heating. By 
the uuion of piperidine and piperic acid piperiue, the 
active principle of Piper nigrum, is formed. The last 
stage of this synthesis is synonymous with the form- 
ation of atropine from tropine and tropic acid, for 
piperidine and piperic acid are the products which 
are formed by decomposing piperine with alcoholic 
potash. It will be noticed that in the case of atropine 
it is the acidulous product which has been formed 
artificially, whereas with piperine it is the basic product. 
Ooniine and some other alkaloids have also been 
synthetically prepared, but as yet only on the experi- 
mental scale, and not from the ultimate organic bases, 
pyridine and chinoline, or their homologues. Since 
Perkins's endeavours to prepare artificial quiuine by 
the oxidation of allyltoluidine, many chemists have 
followed in his track; as yet they have been baffled, 
but success seems more possible now than it was ten 
years ago. The suggestion has been put forth that 
amorphous quinine may be converted into the crystalline 
variety. If this were done, the effect upon the price 
of quinine would not be serious, for any unusual 
demand for the large stocks of this by-product which 
manufacturers hold would naturally make them sus- 
picious, aud they would find ib to their interest not 
to sell. — Chemist and Druggist. 
THE CULTIVATION OF THE CITEON : 
How to Make Candied Lemons. 
The cultivation of citron as an article of commerce 
forms au important industry, which is extensively carried 
on in Southern Europe, and it may be interesting to 
many of our readers to know something about the 
growth of this useful produce, and the process by which 
citrus fruits are preserved by the natives for export to 
the various countries of the world. Under favourable 
conditions great profit is made in the culture of the 
citron, and some hints, therefore, as to the 
planting and rearing of citron-trees, and the best 
mr tlioils of preserving the fruit, may prove useful to 
those already engaged in the industry, and suggest 
a channel for profitable investment to traders who are 
on the look-out for I au opportunity of employing 
capital in the development of any industry which 
promises a fair return for their money. 
The citron was the first of the citrus family introduced 
into Europe. It is closely allied to the orange and the 
lemon, but in its bearing and general appearauce it is 
the most strongly characterised of the genus. The 
citron tree, or shrub, as might naturally be expected, 
will grow wherever lemon or orange trees grow. It 
flourishes, however, only in a sandy soil, aud in the 
immediate neighbourhood of the se i: It is most suc- 
cessful in sheltered situations on the shores of bays. 
As might naturally be expected, it is largely grown on 
the Ligurian coast, which is sheltered by mountains 
from the north wind, and also in the Southern 
Mediterranean provinces of Italy and in Sicily. The 
French island of Corsica is probably the most prolifi 
