48 Spirit of Philosophical Discovery. 
A Vegetable Tallow, extracted by boiling 
from the fruit of the Vateria Indica tree, 
growing in Canara province and others on 
the western coast of the peninsula of India, 
which sells in Mangalore at about 23d per 
Ib., and is called by the natives piney tal- 
low, though not used by them for affording 
light, but medicinally, in plasters, and as a 
substitute for tar in paying the bottoms ‘of 
their boats, has lately been brought to Lon- 
don, in a very hard and tough cake, and 
examined and experimented upon by Dr. 
B. Babington, as related in’ Brande’s 
** Journal of Science ;” it is of a whitish 
yellow colour, and rather greasy to the 
touch, with some degree of waxiness, al- 
though when strongly pressed within seve- 
ral folds of blotting-paper, it communicated 
elain in a slight degree only to the inner- 
most fold. At 60° Fahrenheit, the specific 
gravity of piney tallow is *9260, but at its 
melting point, 973°, this is decreased, by 
the expansion of the mass, to ‘8965. It 
can, with facility, be made into mould 
candles, which afford as bright a light as the 
best animal tallow, and without any un- 
pleasant smell, even when blown out. 
Finding this substance to mix readily with 
animal tallow, spermaceti, or wax, the 
doctor caused several candles to be cast in. 
the same mould, and with similar wicks, of 
twelve threads, weighing about 775 grains 
each, on the average: these candles, in a 
still apartment, of the temperature 55°, 
were burned, without snuffing, during one 
hour, and the losses of weight, by com- 
bustion, were found to be as follow, viz. 
152 grains, halfspermaceti and half piney tallow. 
15] ---+-- spermaceti alone. 
146 «++ half wax and half spermaceti. 
138 «+--+ half wax and half piney tallow. 
136 +--+. wax alone. 
Mi «+--+ *. half tallow and half piney tallow. 
T04}- +++ + tallow alone (average of 7 exp.) 
100 «+++ piney tallow alone. 
That 23 per cent. more of wax than of ani- 
mal tallow should, in the same time, be con- 
sumed in similar candles, seems an unex- 
pected result: When the doctor used com- 
mon-rolled wax candles, of the same dia- 
meter as the others, but with much smaller 
wicks, the average consumption was ]22 
grains, still giving a consumption of wax 
10 per:cent. greater than of tallow: but 
photometric measurements* are here want- 
ed, for supplying the necessary data for 
useful economic dedications. ‘The doctor’s 
analysis of piney tallow, seems to shew its 
atoms to stand as follows, viz. ten of car- 
bon, nine of hydrogen, and one of oxygen; 
in the latter particular, confirming Berza- 
lius’ hypothesis, as to organized substances 
containing always one of oxygen. 
The Snuffing of Candles, although so es- 
sential to their yielding a proper portion of 
* In the Phil. Trans. for 1825, p.2, also in Brande’s 
Jour, of Sci., Yr. W. Retchie’s new Photometer is 
described, and appears well adapted to its purposes. * 
[Aug. 1, 
light, is known to increase their rate of 
consumption; in order to determine the 
quantum of this increase, Dr. B. Babing- 
ton lately experimented on six tallow can- 
dies, all of them having cotton wicks of 
twelve threads, from the same ball, and 
cast in one mould, from similar tallow ; 
the six candles weighed at first ‘6728 Ibs., 
or 9°61 of them went to a pound avoirdu- 
poise: they were all of them lighted at the 
same time, and snuffed together every ten 
minutes during one hour, and then, being 
extinguished, ‘0891 Ibs. of tallow were found 
to have been consumed ; the same candles. 
were then lighted again, and burnt during 
one hour without any snuffing, and, there- 
by, were found to have decreased in weight. 
‘0867 Ibs.; the consumption, “by. snuffing, 
being increased about 27 per cent. ; an in- 
crease so trifling, as not to be compared 
with the increase of light, and avoidance of 
the nuisance of smoke, which the snufiing 
occasions. she 
The preparation of Potash from the green 
Stalks of Potatoes, has been attempted in 
France by M. Mollerat; who, on cutting 
off the stalks immediately before flowering,. 
and, on other plots, deferring the cutting off. 
the stalks until two or three months after 
the flowering, found that the yield of sub- 
carbonate of potash was, in the first in-, 
stance, 3'5 times those of the latter cut- 
tings ; but the yield of potatoes were in the 
latter cases 9°7 times that of the first ! 
M. Mollerat found powdered gypsum, used. _ 
as a manure, considerably to increase the 
crop of roots, but animal manures princi- 
pally increased the stalks of potatoes. 
A Substitute for Indian Ink, equal to it 
in colour and goodness, may, Professor 
Jameson says, be prepared by dissolving 
six parts of good isinglass in twelve parts 
of boiling water; dissolve also one part of 
Spanish liquorice in two parts of hot water; 
mix the two liquors whilst warm, and gra- 
dually incorporate with them, by means of 
a wooden spatula, one part of the best 
iyory black, in very fine powder. 
heat the mixture in a water-bath, until the 
water be so nearly all evaporated, that the 
black paste can be made up into the requi- 
site forms, and the drying thereof com- 
pleted. 
The Electric Powers of Oxalate of Lime 
seem, according to recent experiments by’ 
Mr. Faraday, to place this substance at the 
head of the list of all substances as yet 
tried, as to its power of becoming posi- 
tively electrical by friction, although the 
oxalates of zinc and lead produce none of 
these effects. 
- Formic Acid, according to the recent 
experiments of M. Dobereiner, may be. 
regarded as constituted of one volume of 
the vapour of water, and. two volumes of 
carbonic oxide gas; or, of two atoms of 
carbon, one of hydrogen, and three of 
oxygen. 
PROCEEDINGS 
Then’ 
