149 THE TR0P»6AL AGRICULTURIST. [September i, 1888. 
tdgether, in which the seedling with its shortened 
taproot was planted after the compartments had 
been filled ai follows: — 
a. With vegetable mould, such as is found in the 
primitive forest on the surface of the ground, and 
Which for brevity 1 shall here call humus, as it in a 
great measure consists of more or less decayed vege- 
tation, 
Ik With two parts of the humus mentioned under a, 
mixed with two parts of chocolate-colored subsoil ; 
c. With a mixtare of one part of humus (as above) 
and three parts of subsoil (as above) ; 
d. With unmixed subsoil. 
A few days ago, after the plants had grown for 
about 8 months, I laid bare the system of roots with 
the help of water, cut them off, and, after drying them, 
weighed separately those contained in each compart- 
ment. The relative weights in the compartments a, b, 
c, and rf, were, in the case of Succirubra, 425, 170, 
155, 70 j Officinalis — not ascertainable, as the plant 
died during the experiment. 
The roots were most fully developed in the 
forest soil which was the richest in humus, whilst 
the development diminished in a remarkable degree, 
as the proportion of subsoil was increased. This pheno- 
menon might almost have been predicted from the 
nature of the cinchona tree, which only attains its 
full strength spontaneously in the virgin forests of 
the Andes, and which especially spreads out its system 
of roots horizontally and parallel to the surface of the 
soil, while its weak taproot extends but a little into 
the subsoil. The experiment places the matter beyond 
d oubt, 
I arranged for making similar experiments with 
regard to composts, but was not successful — for the 
bamboo baskets became mouldy and decayed to such 
an extent as to destroy some of the plants, 
and the rest were so ill-developed, that it was impossible 
to consider the results as normal. To obviate this for 
the future, I had some large earthen pots made, in 
which the before mentioned partitions were formed 
and baked at the same time. These partitions I ren- 
dered impermeable by means of a mixture of Swedish 
tar and resin, as otherwise, in cDnsequence of osmos is 
through the porous earthen partitions, an interchange 
of fluids would have taken place between the adjoining 
compartments. 
These pots were used in the same way as the baskets 
had been. I hope in a few months, by these means, to 
obtain results of practical use, with reference to mix- 
tures for manuring purposes. 
As the pots have about eight times the capacity of 
the baskets, the plants for experiments can be allowed 
to grow for a longer period, which will naturally increase 
the value of the results. If in this way, it shall be 
satisfactorily established, what kinds of soil and manure 
are most advantageous for the developement of the 
tree, it will remain to be ascertained how far a better 
growth exercises its influence on the formation of the 
much desired alkaloids in the bark. It is by no means 
certain that the fertilizer which forwards the abundant 
growth of wood, leaf and seed will be equally success- 
ful in the production of alkaloids. 
The elaboration of these alkaloids is not the life- 
object of the tree as is the seed -forming. Alkaloid 
appears in the bark, and we desire it to contain the 
greatest possible quantity; but of what its action in 
the bark cells may be, we have no certain knowledge — 
and under these circumstances it is dangerous to pro- 
nounce a priori positive judgment as to the influence 
which the formation of this matter in the cells may 
exercise. 
Since the alkaloids are combinations of " organic 
muous " or cambium, the presence of this elementary 
fluid is indispensable for their elaboration. 
They further contain cellulose, lignine and the combi- 
nations derived therefrom of the same chemical nature, 
which constitute by far the greater part of the tree, 
consisting of carbon, hydrogen aud oxygen called 
hydrates of carbon. 
I'rom this it might be adduced, that fertilizers con- 
taining organic mucus ought above all to excite 
the formation of alkaloids in the bark, and this assump- 
tion finds support in some experiments made by 
the plant-physiologists Sachs, Ville and others with 
regard to the influence exercised by the organic mucus 
on the chemical constitution of plants. Sachs and 
Ville allowed plants of different kinds, such as beans 
and wheat to grow in pure air, and also in an atmosphei e 
impregnated with carbonate of ammonia, and found 
in the latter case that the organic mucus of the 
plants was remarkably increased. 
In some cases a vigorous development of the plant 
itself is the consequence of the use of manure which 
is rich in organic mucus ; in other instances on the 
contrary the plants show little return|for combinations 
of organic mucus or cambium, and improve more by 
being manured with alkalies and phosphates, and this 
without reference to the quantity of organic mucus 
elaborated in the full grown plant. Thus cereals and 
grass grow best in soil manured with nitre, 
ammoniacal salts, guano or stable manure, whilst 
clover in particular is best excited to robust 
vegetation by alkalies and phosphorus. Nevertheless, 
the produce of a well-grown clover field contains 
twice or thrice the quantity of organic mucus as 
does that of a corn field of the same superficial extent. 
It is evident that the quantity of organic mucus in 
the produce does not always define the kind of ferti- 
lisers most favourable to its growth. Something similar 
may also be the case in respect to cinchona, and it is 
thus desirable that we should be enlightened by experi- 
ments carried out for that purpose. 
Broughtou made experiments by manuring offici- 
nalis, and thereby arrived at the most favourable and 
surprizing results, since the proportion of quinine 
from trees to which stable manure had been applied 
every six months was duriDg five years 7 per cent, 
whilst the uumanured trees yielded only 2 - 4 per 
cent of that alkaloid. (See Moens's Kinakultuur, page 
173,) Still those experiments were not made with 
sufficient care to enable conclusive deductions to be 
derived from the results obtained ; hence the neces- 
sity of a repetition of experiments of the kind indi- 
cated. Such experiments from the nature of the circum- 
stances require a considerable time for their com- 
pletion, as it will only be after a certain period that 
the required indications of the constitution of the 
tree (should they follow), can be expected. I here 
only make preliminary mention of experiments which I 
commenced putting into operation a few weeks ago 
and by which I hope to learn something more with 
regard to manuring. 
I filled several large wooden boxes of about 
a quarter of a cubic meter in capacity with various 
kinds of earth and compost in which I planted 
suckers from the same tree selected as being rich 
in quinine. In about two years it will be shewn 
by the analysis of the bark obtained from them, if 
the manuring has had any influence on the propor- 
tion of alkaloids yielded by the bark, and if it has, 
what has been the nature of such influence. Every 
one can easily make similar exp3riments, and by such 
means data will be multiplied for the solution of this 
very weighty question. 
Analyses of soil, as far as regards the future growth 
and development of the plant, unconnected with the 
proportion of alkaloids in the bark, give no indica- 
tion that can be relied on in the choice of manure, 
in this respect more is to be expected from em- 
piricism. As cinchona plantations that require manur- 
ing from their commencement are rare exceptions, 
nearly all planters have ample time to institute 
such experiments as will afford them the means of 
arriving at a decided opinion based on facts, of which 
they will stand in such pressing need, when their 
second or subsequent planting shall necessitate the 
use of fertilizers. 
And not only as regards the growth of the plants 
and the proportion of alkaloids in the bark, but also 
with reference to the more or less predisposition 
to the attacks of the so justly dreaded canker, is 
it of much importance to know the effects of the 
manure to be employed. 
As every cinchona planter knows, by the term 
" canker " is signified the root-disease of the cinchona 
