March 9, 1872.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
737 
NORWICH CHEMISTS’ ASSISTANTS’ 
ASSOCIATION.- 
A Lecture on “ Nitrogen ” was given at the rooms of 
the above Association on Thursday, February 29th, by 
Mr. F. Sutton, Mr. A. J. Caley occupying the chair. 
The lecturer, after considering and illustrating the 
negative properties of nitrogen in a free state, proceeded 
to contrast with these its great activity when combined, 
and showed its value in the construction of the type 
formulae of organic compounds. He concluded a most 
interesting lecture with an exhortation to his hearers to 
follow up the study of organic chemistry. 
At the close of the lecture votes of thanks were carried 
for the lecturer and chairman. 
There was a good attendance. 
Dromtags of JfritttMe Suattks. 
SOCIETY OF ARTS. 
The Study of Economic Botany, and its Claims 
Educationally and Commercially Considered.* 
RY JAMES COLLINS, F.B.S. EDIN. 
Curator of the Pharmaceutical Socictfs Museum. 
{Concluded from page 715.) 
Now, it can be easily seen from this, that such col¬ 
lection of forest products is precarious and objectionable 
in several ways. First, with regard to the collectors 
themselves. It is, as a rule, only when other means of 
employment are wanting that they take to that of col¬ 
lecting, and, even on moral grounds alone, such a life is 
anything but humanizing. Frequently, too, such opera¬ 
tions are interrupted by the caprice of some petty ruler, 
who requires their services in warfare. This is the case 
everywhere. Then often, from causes other than natural, 
the trees yielding the wished-for product are so far apart 
as to necessitate a vast extent of ground to be gone over 
before any quantity can be collected, which greatly adds 
to the cost, and in many cases precludes the possibility 
of collection at all. The transport, too, is difficult, con¬ 
fined very often to human or animal porterage, which 
will not allow of bulky articles being collected. Many 
valuable woods labour under this disadvantage, and 
unless they are on the margin of navigable rivers, and 
can be thus floated down, they are lost to man’s use. 
Now, the great object of cultivation and acclimatization 
is to centralize and concentrate in a manageable space. 
The modes of collection adopted afford many reasons 
why, in the case of all necessary products, cultivation 
and conservancy should be resorted to. The native 
modes of collection are, to say the least, very destruc¬ 
tive, and entail a great loss of material; for often, were 
cheap means of transit available, other parts now 
wasted could be utilized. We may allude*to four common 
operations employed in the collection of vegetable sub¬ 
stances, viz. (1) the collection of those parts of a plant, 
such as flowers, fruits and seeds, which do not necessarily 
■entail the loss of a life to the plant; (2) the incision or 
tapping of the tree for the collection of gummy and 
milky juices; (3) barking the tree ; and (4) a mode 
wffiich involves the total destruction of the tree. The 
collection of the fruits and seeds of trees does not neces¬ 
sitate the destruction of the tree, but it is quite a com¬ 
mon custom with natives to destroy the tree to save 
themselves trouble. Tapping or incising the bark is re¬ 
sorted to in order to obtain milky juices and gums, such 
as gamboge, india-rubber, gutta-percha, maple sugar 
.and the like. The sugar-maple is generally tapped with 
a three-inch bit to a depth of one and a half to two 
inches. Tapping does not check the growth of the 
* Read on Wednesday Evening, Feb. 14. 
maple, though it injures its wood, and renders it lighter 
and less dense. The general yield of juice is twenty 
gallons in the season of thirty days. Tapping, when 
done judiciously, does not injure the vitality of a free, but 
there are two great dangers in this operation, namely, 
over-tapping, or bleeding the tree to death ; and even 
after judicious tapping, not allowing a sufficient length 
of time to elapse before the operation is repeated. Na¬ 
tives always resort to overtapping, and frequently even 
cut down the tree for the sake of obtaining a larger 
yield. In man}'’ cases they are sure not to visit the same 
spot again, and, therefore, they bleed the tree as long as 
they can. This impoverishes the tree, and predisposes 
it to succumb to atmospheric changes and to the attacks 
of insects, for healthy trees are not nearly so liable to 
these latter destructive agents, and very seldom does a 
tree long survive the united influences. Barking, too, 
in some cases, if carefully performed, does not injure the 
tree; the cork-tree, it is well known, improves under 
the treatment. Mr. M‘Ivor has adopted this method of 
barking cinchona trees, and it is found that it does not 
injure the tree in the least. He thus describes his modus 
operandi :— 
“In removing the strip of bark, two parallel cuts 
should be made down the stem, at the distance apart of 
the intended width of the strip of bark; this done, the 
bark is raised from the sides of the cut, and drawn off, 
beginning from the bottom, care being taken not to press 
or injure the sappy matter ( cambium ) left upon the stem 
of the tree. This cambium , or sappy matter, immediately 
granulates on the removal of the bark, and being covered 
(with moss), forms a new bark, which maintains the 
circulation undisturbed.” 
The renewed bark is nearly as thick in one year’s 
growth as ordinary bark is in three years, and is, more¬ 
over, very much richer in quinine. Mr. M‘Ivor’s me¬ 
thod, I am afraid, is, however, much too delicate an 
operation to be successfully performed by any but skilled 
persons. 
The total destruction, except in the case of herbaceous 
and quickly-growing plants, or where the trunk or other 
vital part of the tree is required for use, is totally un¬ 
called for, and even where necessary, the future supply 
should always be guaranteed by re-planting. This total 
destruction is the more highly reprehensible in the cases 
of trees yielding useful juices, such as india-rubber and 
gutta-percha, with which the subject is more intimately 
connected. The reason assigned is that the yield by 
simple incision or tapping would not be remunerative; 
but this is not the case. The actual reason is the ex¬ 
istence, to a greater or less extent, of a presumed or real 
right of common proprietorship, and the absence of 
government oversight in the forests where this mode of 
collection is practised. Self-denial and forbearance from 
monopolizing any sources of supply are virtues not 
looked for in the most, civilized countries, much less 
amongst untutored savages. 
A collector reasons thus, if he reasons at all on the 
subject: “ If I do not take all I can get, some one. else 
will, and why should I leave that which will enrich a 
less scrupulous collector ?” Even in India, where the 
necessity of forest conservancy is fully recognized and 
carried out, the notion of the inhabitants of a right of 
common proprietorship is a source of constant trouble to 
the Department, and the enforcement of a parental con¬ 
servancy against individual devastation is looked upon 
by some of the inhabitants as a great injustice. Even 
where the right is recognized, and licences arc taken 
out under a full understanding of this tact, constant 
damage is done by excesses. In an able report on the 
caoutchouc foi'ests of Assam, Mr. Gustav Mann says 
“ The privilege was sold (in the Durrung district) for 
1012 rupees to kyahs, in the Mungledye Bazaar, who 
purchased 2500 maunds, but had not the slightest con¬ 
trol over the tapping of the trees by those to whom they 
sub-let their right, and encouraged the latter as much 
