'September so, 1871.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
2G7 
matives Tile or Ulequahuitl , known to botanists as Cas- 
tilloa clastica. The varieties of this rubber known in 
commerce are, “ West India,” “ Carthagena,” “Nicara¬ 
gua,” “Honduras,” “Guayaquil,” “Guatemala.” These 
varieties are here arranged according to their relative 
“value. The rubber is collected by companies of men 
called Uleros , in the following manner :—Having selected 
trees, long, perpendicular incisions are made down the 
trunk, and on either side of it short, diagonal ones, and an 
iron spout is driven in at the basal end of the perpendi- 
•oular channel, down which the crude milk runs into a 
pan holding about five gallons placed to receive it. 
A tree of 4 feet in diameter and about 20 to 30 feet 
to the first branches, yields about 20 gallons, contain¬ 
ing about 40 lb. of pure rubber in solution. At the end of 
“the day this milk is collected and brought to the common 
workshop, where it is passed through sieves to free it 
from pieces of bark and other impurities. In Nicaragua, 
Ihe juice of the Achuca plant ( Ipomoea Bona-nox) is added 
in the proportion of a pint to a gallon of milk. On mixing 
these the rubber quickly coagulates. Where this plant 
is not obtainable, salt water is substituted. To every 
.gallon of milk two gallons of salt water are added. 
These are placed in a barrel, and allowed to stand for 
twelve hours. After the rubber has coagulated it is 
taken out, the water pressed out by the hand, and then 
subjected to the heaviest available pressure, either by 
•using heavy stones, hydraulic presses or rollers. It is 
then hung up wet, exposed freely to the air, and loses 
about two-thirds of its weight. We next turn our atten¬ 
tion to Asiatic kinds of rubber. 
Malayan Archipelago. —Our chief sources of supply 
-fr6m this portion of the globe are Singapore, Borneo 
-and Java. Singapore is but an entrepot for the produce 
of neighbouring countries, native sources being long 
•ago exhausted. Singapore (so-called) and Java rubber 
are obtained from fig-trees. Ficus clastica is the chief 
plant which yields it. This plant is too well known to 
meed any description; its dark green, glossy leaves are 
.■seen everywhere, it being a great favourite as a window 
and greenhouse plant in this country. To obtain the 
india-rubber the trees are incised, and the rubber al¬ 
lowed to trickle down the trunk. When dry, it is col¬ 
lected in the form of strings, and rolled into balls or 
pressed into large slabs. “ Borneo” rubber is collected 
from a trailing, vine-like plant, the Urceola elastica of 
botanists, of which there are three varieties recognized 
by the natives, viz. Serapit, Fetabo and Menungan. The 
juice is treated with salt water, which speedily brings 
about the coagulation of the rubber, the outside of which 
heing acted upon first, encloses small quantities of salt 
water in numerous little cells. 
India. —Assam rubber is the only kind of rubber 
which India supplies to the English market. It also is 
obtained from the Ficus elastica , and is collected in the 
same manner as that of Java and Singapore. 
Madagascar. —This variety, which is beginning to 
figure in our commerce, is obtained from a trailing, vine¬ 
like plant, called by the natives Vanghinia (Vahca sp. 
•of botanists), by incision, and coagulation brought about 
by treatment with salt water or artificial heat. In the 
Johanna and Mohilla islands the same plant occurs. 
Eastern Africa. —In the Zambesi, Zanzibar and Mo¬ 
zambique districts rubber plants have been found, but, 
with the exception of the latter, one parcel of which has 
been sent to England, no quantity of rubber has as yet 
rappeared in commerce. 
Southern Africa. —Efforts have been made to utilize 
fhe sap of various species of Euphorbia , but with no pre¬ 
sent result. 
Western Africa is our chief source of commercial 
arubber in Africa. From the west coast rubber is ob¬ 
tained from climbing plants, which have jasmine- 
scented flowers, and stems of from 4 feet to G feet in 
•diameter. They are found to be a species of Landolphia. 
'The natives cut the stems, and allow the rubber to 
trickle down their arms, and remove it in the various 
forms of balls, tongues, etc. 
By a careful examination of the whole subject, I have 
found that there are six modes of preparing rubber. 
These we may arrange in two groups, thus:— 
Group 1.—Coagulation brought about by heat. Ex¬ 
amples—(1) Artificial heat, ex. Brazilian, etc.; (2) 
Natural heat, ex. Ceara and Ficus group. 
Group 2.—Coagulation brought about by the addition 
of various substances; (3) Alum, ex. Brazilian; (4) 
Certain plants, ex. Nicaragua; (5) Fresh water, ex. 
Nicaragua and Madagascar; (6) Saltwater, ex. Borneo, 
Madagascar. 
Of these methods, that pursued at Para, namely, by 
the careful application of artificial heat, especially if 
aided by the use of sulphur, is undoubtedly the best, and 
produces the finest rubber. The preparation by natural 
heat has the disadvantage of requiring a second visit to 
the tree, whereas, as a rule, the scene of operation has to 
be constantly changed. Of the second group, viz. a icct 
process, in contradistinction to the first group, a dry pro¬ 
cess, the addition of a solution of alum is in great favour 
in Brazil, inasmuch as it enables the operation to bo con¬ 
ducted in the collectors’ own houses, a desideratum of 
great value on the score of health alone as the exhala¬ 
tions from the decaying vegetable matter on the river 
banks, which, on account of the inundations, are nothing 
but mud, are fruitful sources of deadly fevers. The wet 
process, however, has one very serious disadvantage. 
The rubber thus treated is never free, unless very old, 
from water, and dryness is next to purity in constitut¬ 
ing value in rubber. In the Guatemala and Guayaquil 
rubber, a dirty, tarry, resinous matter exudes, which 
greatly detracts from the value, it being very difficult to 
get rid of. In the Borneo kind, when a piece is cut 
through, the water is seen in little cells, and has a very 
saline taste. 
Purity and freedom from false packing is, as already 
hinted, the first and main point to be attended to in 
order to produce a good, marketable rubber. The adul¬ 
teration may arise in various ways:—1st. By careless 
collection, in allowing bark, clay, or other materials, to 
fall into the milk. It is an excellent plan to pass the 
milk through sieves in order to separate these impuri- 
ties. It is important that the form in which rubber is 
made up should not be lost sight of. Large masses never 
will fetch so high a price as small pieces, as in the latter 
case the facility of adulteration or false packing is re¬ 
duced to a minimum. By far the best plan is to prepare 
the rubber in thin, separate sheets, or cakes, and if a 
mould is used to use wooden ones, a large-sized battle¬ 
dore, such as is used by children, being an excellent 
mould in every respect. Secondly, care should be taken 
not to mix the milk of another tree with that of india- 
rubber. Of course this caution should not deter any one 
from searching for such milky juices as are likely to be 
of use to send as samples home. Bad preparation and 
intentional fraud should be guarded against. 
The quality and quantity of rubber is much influenced 
by the time of year at which it is collected, and these 
facts should be noted. The trees require, after each 
tapping, a period of rest of about two years. Binding 
the trees and overtapping injure greatly, and should be 
strenuously guarded against, but many interesting facts 
may be noted in connection with this subject, and would 
prove highly valuable. Total destruction of the tree is 
barbarous and intolerable, and should be put a stop to 
by all possible means. Efforts and experiments should 
be made in the direction of cultivation, and as to how the 
trees are best propagated, and how long they are before 
they come to maturity. As there are some, doubtless, who, 
from residence and other favourable circumstances, would 
be willing to collect a series of specimens which would 
enable a definite opinion to be formed of the value ot 
the rubber, and allow some useful hints to be offered, 
suggestions are therefore made here only as to the kind 
