92 
POPULAR SCIENCE REVIEW. 
How to extract Grease from Bones. — In a comparatively recent number of 
the Revue Hebdomadaire de Chimie,” M. Licbtenberger states that the 
following method, is in his opinion, the best : — The bones are first crushed, 
next treated with high-pressure steam, and to the semi-gelatinous mass thus 
formed is added hydrochloric acid (2 per cent.), with v,’hich the material is 
boiled ; by this operation the fat is separated, and, floating on the top of the 
boiling liquor, is readily collected, and further purifled by treatment with 
boiling water, a very small quantity of caustic soda having been added. 
Next the grease (a fluid oil-like substance) is treated with animal charcoal, 
and lastly filtered. — See also Chemical News. 
An Analysis of a recent Meteorite, which Herr Ilaidinger has recorded, is 
given by E. H. von Baumhauer, and appears in the “Chemical News.” 
The composition of this stone is, in 100 parts : — Nickeliferous iron, 5-0 ; sul- 
phuret of iron, 2-2 j chrome iron, 0-8 ; olivine, 39-9 : insoluble bisilicate, 
52-1. 
A Gas~hurnei' for bending Glass Tubes . — The following note may interest 
some of our readers. It is from the “ American Chemist,” and appears in 
the “ Chemical News ” of November 8. The writer, Mr. II. C. Bolton, 
states that he has employed for some years an ordinary bat-wing burner, at- 
tached to a small, short stand (three inches high, burner included), so as to 
rest low upon the table, in order that raising the arms inconveniently high 
may be avoided. Such a burner insures a broad flame, by which the tube 
is heated for two or more inches in length the tube is turned while in the 
flame, and removed for bending as usual. The deposit of carbon, which at 
first sight might seem an objection, is really one of the chief advantages 
of using this burner. On placing the glass in the flame, the deposit begins 
immediately, and prevents too rapid a rise of temperature and consequent 
cracking of the glass ; during the heating the carbon tends to distribute the 
heat equally over the surface of the tube ; and finally, on withdrawing the 
glass from the flame too sudden cooling is prevented, and the glass is, as it 
were, annealed. The black deposit is readily removed by a diy cloth. This 
plan was commonly employed in “ Hofmann’s Laboratory,”Berlin. In bending 
tubes of more than three eighths of an inch in diameter, the end should be 
closed tightly with a cork (or wax), and air blown into the other end at the 
moment of bending the tube ; by regulating j udiciously the pressure of the 
air upon the sides of the somewhat softened tube, the latter will neither 
bulge out nor collapse, but will retain its proper calibre. This cannot be 
effected, however, with very large tubes, or with very thin ones, which 
require the nice manipulation of the professional glass-blower. 
Explosion caused by a Mixture of Acetate of Soda and Nitrate of Potass . — 
In the “Journal de Pharmacie et de Chimie” for November it is stated 
that while M. Violetti recently was heating a mixture of nitrate of potash 
and acetate of soda in a small glass flask, he was seriously injured by a 
sudden and violent explosion of the substances he operated upon. This 
iiccident gave rise to further investigation, the result of which is that a 
mixture of 100 parts of nitrate of potassa and 60 of acetate of soda, when 
heated and fused at about 300°, do not explode, and may even, after cooling, 
be pulverised and granulated ; but if the salts are heated to 350°, or ignited 
by means of red-hot iron, a violent explosion instantly takes place. When 
