Forgot your password?  

Resources for students & teachers

This eBook from the Gutenberg Project consists of approximately 112 pages of information about Scientific American Supplement, No. 315, January 14, 1882.

When the coarser stones, etc., are weighed, and the purified portion decomposed, absolutely correct results are obtained, and in this way the awkward discrepancies from different analysts may be avoided.—­Chemiker Zeitung, v. 7, p. 703.

* * * * *

TESTING WHITE BEESWAX FOR CERESINE AND PARAFFINS.

BY A. PELTZ.

The method which is here recommended originated with Dr. M. Buchner, and consists in preparing a concentrated solution of alcoholic caustic potash—­one part caustic potash to three of 90 per cent. alcohol—­and then boiling one to two grammes of the suspected wax in a small flask with the above solution.  The liquid is poured into a glass cylinder to prevent solidification of the contents, and it is then placed for about one half hour in boiling water.  With pure wax the solution remains clear white; when ceresine and paraffine are present, they will float on the surface of the alkali solution as an oily layer, and on cooling they will appear lighter in color than the saponified mass, and thus they may be quantitatively estimated.  The author likewise gives a superficial method for the determination of the purity of beeswax.  It depends on the formation of wax crystals when the fused wax solidifies.  These crystals form on the surface on cooling, and are still visible after solidification when examining the surface from the side.  The test succeeds best when the liquid wax is poured into a shallow tin mould After cooling another peculiar property of the wax becomes apparent.  While the beeswax fills a smaller volume, that is, separates from the sides of the mould, the Japanese wax, without separating from the sides, becomes covered with cracks on cooling which have a depth corresponding to the thickness of the wax.—­Neuste Erfindungen und Erfahrungen, viii., p. 430.

* * * * *

THE PREVENTION OF ALCOHOLIC FERMENTATION BY FUNGI.

BY PROF.  E. REICHARD.

The manager of a well directed brewery, which was built according to the latest improvements and provided with ice-cooling arrangements, found that the alcoholic fermentation of lager beer did not advance with proper regularity.  The beer did not clarify well, it remained turbid and had a tendency to assume a disagreeable odor and taste.  Microscopic examination of the yeast, however, showed the same to be bottom yeast.  After some time its action apparently diminished, or rather, the fermentation, which began well, ceased, and at the same time a white foam formed in the center of the vat.  The manager observing this, again submitted it to microscopic examination.  The instrument revealed a number of much smaller forms of fungi, similar to those of young yeast, and some which were excessively large, a variety never found in bottom yeast.  Fully appreciating the microscopic

Follow Us on Facebook