M. Amagat has succeeded in solidifying various liquids, by compressing them in cylinders of bronze and steel. He has also photographed the crystals after crystallization, by means of a ray of electric light traversing the interior of the vessel by glass cones serving as panes. The stages of crystallization can be observed in this way with chloride of carbon, and it is seen that the process varies with the rapidity with which the pressure is produced. If rapidly, a sudden circlet of crystals gathers round the edge of the luminous field, and grows to the center. The pressure being continued, the field becomes obscure, then transparent. As the pressure is diminished the reverse takes place, and the liquid state is reproduced. M. Amagat finds that chloride of carbon solidifies at 19.5 deg. Cent., under a pressure of 210 atmospheres. At 22 deg. Cent., benzine crystallizes with a pressure of about 900 atmospheres. * * * * * THE SCIENTIFIC AMERICAN SUPPLEMENT. PUBLISHED WEEKLY. Terms of Subscription, $5 a year. Sent by mail, postage prepaid, to subscribers in any part of the United States or Canada. Six dollars a year, sent, prepaid, to any foreign country. All the back numbers of THE SUPPLEMENT, from the commencement, January 1, 1876, can be had. Price, 10 cents each. All the back volumes of THE SUPPLEMENT can likewise be supplied. Two volumes are issued yearly. Price of each volume, $2.50 stitched in paper, or $3.50 bound in stiff covers. COMBINED RATES.--One copy of SCIENTIFIC AMERICAN and one copy of SCIENTIFIC AMERICAN SUPPLEMENT, one year, postpaid, $7.00. A liberal discount to booksellers, news agents, and canvassers. MUNN & CO., PUBLISHERS, 361 BROADWAY, NEW YORK, N. Y. * * * * * PATENTS. In connection with the SCIENTIFIC AMERICAN, Messrs. MUNN & Co. are solicitors of American and Foreign Patents, have had 42 years' experience, and now have the largest establishment in the world. Patents are obtained on the best terms. A special notice is made in the SCIENTIFIC AMERICAN of all inventions patented through this Agency, with the name and residence of the Patentee. By the immense circulation thus given, public attention is directed to the merits of the new patent, and sales or introduction often easily effected. Any person who has made a new discovery or invention can ascertain, free of charge, whether a patent can probably be obtained, by writing to MUNN & Co. We also send free our Hand Book about the Patent Laws, Patents, Caveats, Trade Marks, their costs, and how procured. Address MUNN & CO., 361 BROADWAY, NEW YORK. Branch Office, 622 and 624 F St., Washington, D.C. * * * * * THE SCIENTIFIC AMERICAN ARCHITECTS AND BUILDERS EDITION. $2.50 A YEAR. SINGLE COPIES, 25 CTS.