SCIENTIFIC SUM^tlAEY. 
309 
sion in sulpliiuic acid, and gently moistening the fracture with the tip of 
the tongue, bubbles of gas arise, causing the wetted portion to appear to 
boil. The most careful washing and coating with lime, after being dipped 
in the acid, and even its subsequent drawing, in which process it is reduced 
in diameter by passage through a die, does not interfere with either of these 
phenomena, which only gradually disappear by exposure to the air, or more 
quickly by gentle heat. Prolonged immersion in acid has a tendency to 
produce a crystalline structure in even the best wrought-iron. 
The Chemistry of the Sugar-forming Powers of Liver. — This is stated 
somewhat briefly by M. Nencke in the “ Chemical News.” The quota- 
tion refers especially to the withdrawal of water, wliich, the author says, 
in non-nitrogenous substances is at present only known in one instance, 
with formation of anhydride, viz., in the conversion of grape sugar into 
glycogen. According to researches made by Dr. Schopfer in the laboratory 
at Bern, which fully confirm the exhaustive ones of Dr. Bernard on this 
subject, solutions containing 15 per cent, of grape sugar, and injected into 
the branches of the vena portarum, are retained by the liver, while, if the 
same solution is injected in any other vein of the body, two-thirds of the 
sugar injected is emitted w’ith the urine. Dr. Schopfer calculated from his 
experiments that the liver of a medium-sized rabbit can in one minute con- 
vert about 0T2 grm. of sugar. It is scarcely possible to assume that the 
sugar should not be retained in the shape of glycogen, since he says that 
he has found that when substances containing sugar have been given as 
food, the blood of tbe vena portarum always contains sugar, while glycogen 
is simultaneously largely generated in the liver. The formation of the 
cholesterine of wax, and that of the fats from carbohydrates in the animal 
organism, can only be explained by the elimination of 0 in the shape of 
OHj, aided by a partial oxidation of the original substance. 
The Chemistry of the Allyls Compounds. — The “ Proceedings of the Che- 
mical Society of Berlin” for April 28 contain a paper on this subject, by 
M.M. A. Kekule and A. Binne. It seems that allyl alcohol is readily 
attacked by dilute chromic acid. Even in the cold the odour of acrolein is 
•observed, and carbonic acid escapes. If the liquid is distilled, after some 
time formic acid is detected in the distillate, but not acetic acid. If the 
same alcohol is treated with nitric acid, there is no odour of acrolein. 
Formic acid without acetic appears in the distillate, and there is much 
oxalic acid in the residue. The behaviour of the iodide and cyanide of allyl 
with chromic and nitric acids was also examined. 
Examination of Air hy means of Cold. — Professor Smee recently, at the 
Berlin Chemical Society, proposed a method for detecting organic matters 
contained in the air, and for effecting at the same time a kind of distillation 
by cold. A glass funnel, closed at its narrow end, is held suspended in the 
air and filled with ice. The moisture of the air is condensed in contact 
with the exterior surface ; it trickles to the bottom of the apparatus, and 
falls into a small basin placed for its reception. The liquid obtained in a 
given time is weighed. It generally contains ammonia, which is deter- 
mined by known methods. Distillation by cold may be employed for sepa- 
rating volatile substances which might be injured by heat. Thus if flowers 
are placed under a large bell-glass along with the refrigerating funnel, a 
