1829.] 
Scientific Intelligence. 
307 
parates be repeatedly boiled in fresh quantities of water, in order to remove from it 
the whole of the alkali. Then collect it. The object of this experiment is to ascer- 
tain if the albumen will be held in solution by the alkali, while the caoutchouc 
alone will be precipitated. 
N. B. This experiment may be repeated with several different portions of alkali, 
both greater and less, than that we have recommended. 
6. Mix the juice with twice its bulk of strong spirits ; agitate the mixture 
thoroughly for half an hour ; then collect the matter which separates. 
7. Mix the juice with as much pure distilled vinegar as communicates to it a 
pretty strong sour taste. Agitate the mixture thoroughly ; then collect the solid mat- 
ter which separates, and carefully wash out the whole of the vinegar from it with 
water. 
8. A similar experiment may be made by adding very dilute sulphuric acid to 
tile juice, but in this case the greatest precaution must be taken, not to leave a 
trace of the acid in the precipitated caoutchouc. 
9. Make thick varnish with recently prepared caoutchouc, by cutting it into 
small pieces, and mixing it with four times its bulk of the bestspirits of turpentine, 
stirring the mixture at intervals for twenty-four hours, until the materials seem to 
be completely incorporated. Then put the varnish into a bottle, cork it up, and 
seal it. 
It is of some consequence, that the caoutchouc employed in this trial should he 
as little coagulated as possible, because it will be in a proportionate degree more 
easily divided and dissolved by the oil of turpentine. 
The caoutchouc which is separated by merely dilating the juice with water, (if 
this is found to succeed,) would be extremely suitable for the purpose ; or this fail- 
ing, the caoutchouc which is separated from the juice jby the addition of alcohol or 
strong spirits. 
10. Fill some bottles with the juice the instant it issues from the tree, cork 
them up, and seal them on the spot. 
A specimen of caoutchouc prepared by each of the methods which have been 
mentioned, as well as by any other method which an observation of the local pro- 
cesses may suggest, should be transmitted to England for the purpose of being further 
examined there . And in order that the products of these various trials may be com- 
parable with one another, it will of course be necessary that they should be all made 
from juice of the same kind, and that the same quantity of juice should be takenfor 
each trial. 
The quantity of juice taken for each trial may be from 1 to 6 pounds, according 
to the convenience which is possessed for experimenting. The caoutchouc prepar- 
ed in all these trials should be dried, if possible, without the application of artilicial 
heat, or even without being much exposed to the sun. It should then be packed 
up in a piece of matting, and directions be given for its being kept in a part of the 
ship where it will be rather dry than damp, and where it will be exposed occasion- 
ally to the air : for it is apt to become mouldy when kept excluded from the uir. 
X . — Scientific Intelligence. 
1. Novelties in Science. 2. Miscellaneous Notices. 3. New Patents, 
4. New Publications. 
Under the above titles we propose to give a series of articles, noticing every no- 
velty, whether of fact or doctrine, that may appear in the European J ournals ; and we 
solicit towards the proper execution of the task, the co-operation and contributions 
of our friends and correspondents. Notices of new publications on subjects of 
science, or of new editions of established works will find their place. And though, we 
shall not attempt to give an account or even list of all the new patents, yet we hope 
to present our readers with concise notices of all that are likely to be generally in- 
teresting, or that describe processes, which tend to any important change of mani- 
pulation in any of the arts. 
