164 EXTRACTS PROM FOREIGN JOURNALS. 



CHEMISTRY. 



Congelation of Mercury in the Open Air at Gardiner, Maine, 

 North America. By Mr. Hall — It was extremely cold on the 28th of 

 January, 181?. A bed of charcoal was placed toward evening upon a quay, 

 three hundred feet from any habitation . A little mercury was placed in 

 blackened phials. The thermometer indicated _ 29" ( — 27°, 1, H.) at ten 

 o'clock at night. At half-past three in the morning it altered to — 32° ( — 

 28°, 4, R.). At half-past six it was — 40° ( — 32°, R.). The mercury was 

 fluid in the phials, but some drops which had been placed in a hollow cavity 

 in the charcoal was partly congealed. When touched with a small stick, the 

 mercury separated into angular and evidently crystalline fragments. This 

 appearance, destroyed by the heat occasioned by the body of the observer, 

 re-appeared at seven o'clock, but soon afterwards the rising of the sun put 

 an end to the experiment. 



Solubility of Oxide or Lead in Water.— M. Bonsdorff announces 

 that oxide of lead, prepared by exposing the metal to a damp air, or even by 

 decomposing with fire nitrate of lead, is entirely soluble in water. Seven 

 thousand parts of water are required to dissolve one of the oxide, and the so- 

 lution presents a powerful alkaline re-action, colours syrup of violets green, 

 and is an excellent exciter of carbonic acid. 



MINERALOGY. 



Crystal of Columbite of remarkably large Dimensions. — Some 



years ago a new source of Columbite was discovered inclosed in a mass of 

 feldspath, near Middletown, U. S. The crystals found there have already 

 been described in Mr. Shepard's Mhieraloi/y, and " are remarkable," according 

 to him, " for their regularity, their brightness, and then- very large size. 

 Some of them weigh from three to four ounces. The substances associated 

 with the columbite are uranite, albite, and phosphoric lime." Very lately a 

 still larger mass of columbite has been found in the same locality, it weighs 

 61bs. 12oz. ; the entire mass weighs 14lbs., but it was already much broken 

 when taken from the bed. This piece, although sufficiently irregular, evi- 

 dently forms part of a regular crystal, the incidence of whose faces might 

 have been determined by the goniometer. In its interior are fixed pieces of 

 feldspath and quartz, and some of the faces of fracture are bcrdered with 

 uranite. The specific weight of this specimen is 5,4 — Silliman's American 

 Journal, July, 1836. 



BOTANY. 



On Stipules.— Stipulse are sometimes considered as distinct organs from 

 the leaves, sometimes as accessories of the true leaves. The following pas- 

 sage, extracted from the second edition (London, 1835) of Dr. Lindley's In- 

 troiliiction to Botany, may tend to settle this question. "Nothing is common- 

 er than to find (in Roses) a leaflet accompanying a stipule ; and in a specimen 

 of Rosa bracieata, which I have examined, there were no stipules, but in their 

 place two pennate, exstipulate leaves. Consequently, stipules should be 

 considered as leaves in a rudimentary stale.— Bibliotheque Universellc de Ge- 

 neve, Fibniary, 1837. 



