698 THE TROPICAL AGRICULTURIST. [April r, 1890. 
but its economical employment on the large sea's rl e 
pended on the use of suitable apparatus whereby the 
solvent could be recovered from each operation with 
very little loss. It was for this reason that I considered 
a properly furnished factory to be essential to success ; 
and, as I have stated, the Government was prepared 
to sanction the expenditure necessary for this purpose. 
At this time then the arrangements were matured 
for starting a factory and putting the fusel oil process 
in operation. But at the same period there were 
reasons of a personal kind which made me anxious 
to return to England, and on this account I wished to 
tender my resignation. It seemed to me a suitable 
time for taking this step, because any successor to 
my appointment having to take the superintendence 
and control of the manufacture, would naturally prefer 
that the factory a' d its appliances should be arranged 
under his own direc' ion. borne informal correspondence 
on these points passed between the Lieutenant- 
Governor and mj self, in which Sir Ashley Eden at 
first very kindly asked me to reconsider the course I 
wished to take : but ultimately my resignation was 
accepted. It was suggested that the Secretary of 
State would possibly select a young chemist for the 
appointment, who would be willing to take up and 
carry out the plans already made for starting the 
manufacture. In that case I undertook to work with 
him on the subject for a timejn London, and render 
him what assistance I could in acquiring information 
that might be useful to him in putting the process 
into operation. 
I returned to England in the autumn of 1879, and 
a few months later I had an opportunity for making 
myself further acquainted with the employment of 
mineral oils in the extraction of quinine. The use 
of these agen s had been already tried in India. Mr. 
Broughton experimented with them, but did not ob- 
tained any economical success (see his Report, dated 
1st December 1873). Some experiments wish such oils 
had been also made by myself, but with no very 
satisfactory results. Nevertheless, in some of the 
principal quinine factories of Europe, a process of 
extraction with mineral oil was being employed. In- 
deed, the oil proce-a bad largely superseded all others. 
I found that only certain kinds of oils, namely, the 
paraffins oils ob'ained in the distillation of " brown 
coal," or schist, were well adapted for this process, 
the products of American petroleum being unsuitable 
for the extraction of quinine. I procured some oil 
from Young's Paraffine Works, and made some trials 
with it in the extraction of calisaya bark from the 
Sikkim plantations, and obtained much better results 
than I had clone before. Nevertheless, it appeared to 
me that the employment of this process in India would 
be attended with considerable difficulty. 
Fusel oil still presented to my mind many advantages 
for use in that country, but I began to see the way to 
a further simplification in the method of employing it. 
In the process I bad selected in India, fusel oil alone 
was usee! as the solvent. It now occurred to me that 
by previously diluting it with some liquid hydrocarbon 
a considerable improvement would result. In this case 
the fusel oil would be the active solvent; but the 
presence oE a considerable proportion of a hydrocar- 
bon, such, for instance, as any mineral oil or naphtha, 
would exclude some of the impurities otherwise taken 
up by the fusel oil when used alcne, and the alkal- 
oids would be at once obtained in a much greater 
state of purity. I soon satisfied myself that the 
employment of a mixed solvent, of this description 
would have many advantages over the use of fusel 
oil alone. But a considerable time bad elapsed, and 
no fresh appointment to the post cf Quinologist had 
been made. I learnt that the Government did not 
consider it desirable i.o send out another chemist. Un- 
d r tbe^c circumstances, J was not in a position to make 
any further suggestions regarding the process of manu- 
facture at S kkim, and I therefore let the matter drop. 
Later on, however, I heard that Mr. Gammie, who 
stil conducted the mat ufacture of febi il'uge, was also 
attempting the manufacture of pure quinine sulphate 
from the calisaya bark ; and a correspondence beg; n 
between Mi'. Gammie and myself oh this' subject. At 
about this time Dr. King came on a visit to Europe, 
and in the autumn of 188-1, 1 had au opportunity of 
discussing with him the practicability of the efforts 
Mr. Gammie was making at Mungpoo. At that time 
a spirit process was under trial, and the results pro- 
mised considerable success. The alkaloid was com- 
pletely extracted from the bark, but it was associated 
with much impurity, and its purification rendered the 
process somewhat too complicated for use on the 
plantations. Dr. King, during his stay in Holland, 
had acquired some valuable information regarding the 
paraffine oil process as used in the Continental oil 
factories, and he consulted me regarding it. I was 
impressed with certain difficulties, which I thought 
would attend its employment by Mr. Gammie, and 
I did not feel that I coulel then assist him much in 
that direction. It seemed to me, however, a favourable 
moment to make a further trial of the modification 
of the fusel oil process to which I have already referred, 
namely, the employment of fusel oil diluted with some 
liquid hydrocarbon for the extraction of the bark. 
Accordingly, I resumed my experiments on the use of 
such a mixed sjlveut, and worked out two or three 
alternative processes. These differed from each other 
chiefly in the nature of tie diluting hydrocarbon. In 
one, the mixed solvent was formed by diluting the 
fusel with five or six times its volume of the volatile 
portion of coal tar rupbtha. The principle of this 
process 1 communicated to Dr. Rt-dwood, one of the 
editors engaged in preparing a new Pharmacopceia, as 
likely fo furnish the basis of a convenient analytical 
methed for determining the alka'oirial value of the 
cinchona bark used in medicine, and the process is now 
the official test for that purpose in the present 'British 
PI armacopcoia. The use of a volatile naphtha, whether 
derived from coal, shale, or petroleum, for diluting 
the fusel oil, presented several advantages for a manu- 
facturing process; bnt it was probable that there 
would be grrat difficulty in obtaining any such naptha 
in India. In another of the processes I devised, the 
fusel oil was therefore diluted with ordinary kerosiue. 
As this oil is so largely used for illumirating purposes 
in India, and is therefore so readily obtainable there, 
this method offered the greatest facilities for imme- 
diate trial. 
When Mr. Gammie visited England in the summer 
of 1885, he came to my laboratory and witnessed the 
experimental working of this process; and formed a 
favourable opinion of its adaptability for use on the 
plantations. On his return to Mungpoo, he began a 
trial of the method in extracting calisaya bark, and 
the satisfactory results he obtained encouraged him 
to go on. With great perseverance he mastered one 
detail after another, using only the simple app'iances 
that he found at hand, until he was able to employ 
the process on a considerable scale. The valuable 
results, therefore, which have been thus far attained 
in the practical application of the process, are entirely 
due to h's skill and energy. 
A description of the process as it was being con- 
ducted at the commencement of this year was drawn 
up by Mr. Gammie, and was published with the Gov- 
ernment Resolution of the 26th March 1888. Since 
then, I believe, he has effected a further improvement 
in the mechanical arrangements, and is now in a 
position to work from 3,000 to 5,000 lb. of bark per 
week. A considerable quantity of quinine sulphate 
has been produced and issued. Samples of this have 
been analysed, and the results show that both iu 
purity and appearance it is equal to the best European 
quinine. There appears to be no doubt that the extract- 
inn is complete, the amounts of quinine obtained corres- 
ponding well with the kuown composition of the bark. 
As yet only calisaya bark lias been worked by this 
process 1 . This bi rk contains a large amount of quinine 
associated with v< ry little cinchomdine; consequently 
the final opeiaticns for obtaining pure quinine sulphate 
are very simple. But the plantations will also furniBh 
much bark, espec : al)y from hybrids, which contains a 
considerable amount of quinine associated with a 
large amount of cinchonidine. Such bark will no doubt 
be utilised in the preparation of pure quinine as soon 
. s the further arrangement necessary for separating 
