144 Scientific Intelligence. 
treated with sulphurous acid in excess, boiled, cooled, made up to a 
liter, and examined in the cuprimeter.—/J. Chem. Soc., xxxvii, 
418, June, 1880. SS 
4. On a Method of producing Acetal_—tIn the hope of produc- 
ing in larger quantity, a crystalline substance which they had 
observed, ENerr and Dx Grrarp dissolved aldehyde in about its 
own volume of absolute alcohol and passed into it a current of 
hydrogen phosphide gas for three days, the mixture being at first 
cooled to — 40°, then to — 21°. o erystals were formed; but 
on adding water a liquid separated, which gave on fractioning a 
liquid boiling at 104°, having an ethereal odor, a specific gravity 
of 0°829 at 13°, and a vapor density of 4:3. Moreover, it pos- 
sessed in other respects the characters of acetal. The yield is 
considerable. The authors are now investigating the conditions 
of maximum production.— Bull, Soe. Ch., Ul, xxxiii, 457, May, 
1880 G F. B 
5. On Phlobaphen and Oak-red, and their Relation to Tan- 
in.—B6TTINGER has proved that, under the influence of sulphu- 
tan. tera second extraction with ether, the lumpy residue 
consisted essentially of two constituents — tannin, soluble in water 
and phlobaphen, insoluble in it. Their complete separation was 
sulphuric ecomes a thick mass which liquefies on gentle 
heating. At higher temperatures decomposition takes place, @ 
compact brownish mass of oak-red is deposited and’ r remains 
in solution ak-red and phlobaphen are identical in their physi- 
cal properties and in their behavior to oxidizing agents, zinc dust, 
fused potash, acetic oxide, benzoyl chloride, fuming hydrochloric 
As purified i i i 
