General Science. 451 
night to the open air, till its temperature is in equilibrio with the 
cold of the atmosphere. It should then be placed in the ice- 
house, about six o’clock in the morning, when the air becomes 
warmer. In order to prove the advantage of that«^ethod, he sup- 
poses that two ice-houses have been filled with ite, one with ice at 
S2°5 and the other with ice at 14°. ^ When a sixth part of the ice 
at 32° is melted, the ice at 14° will be untouched, but its tempe- 
rature will have risen to 32°. One-sixth part of the whole, there- 
fore, has been saved by laying it "up at a low temperature. — . 
Annal. Generales des Science Physiques, tom. ih: num. 7. 
44. Printing from the Fusible Metal — M. Gassicourt proposes 
to take impressions from recent MSS. by means of the fusible 
metal. In order to shew the application of it, he pastes a piece 
of white paper on the bottom of a china saucer, and allows it to 
dry: he then writes upon it with common writing ink, and 
sprinkles some finely powdered gum-arabic over the writing, 
which produces a slight relief. When it is well dried, and the 
adhering powder brushed off, the fusible metal is poured into 
the saucer, and is cooled rapidly to prevent crystallization. The 
metal then takes a cast off the writing ; and when it is immersed 
in slightly warm water, and any adhering gum removed, impres- 
sions may be taken from it as from a copperplate. 
Aet. XXXIX .- — List of Patents granted in Scotland since 
23d November 1820. 
11. To John Birkenshaw of Bedlington Iron- Works, in 
the parish of Bedlington, county of Durham: — For certain 
Improvements in the manufacturing and construction of a 
wrought or malleable iron rail road or way,” Sealed at Edin- 
burgh, 30th December 1820. 
12. To Andrew Turnbull of the Old South Sea House, 
in the City of London For f«^an improvement in the rudder 
and steerage of a ship or vessel.” Sealed at Edinburgh 30th 
December 1820. 
13. To William Wood of Bow, county of Middlesex; — 
For “ the manufacture of a material or materials for the more 
effectually making and retaining water-tight and seaworthy ships, 
and. other vessels” pealed at Edinburgh 30ih December 1820. 
