[ 321 ] 

 XLVI. InttUigence and Miscellaneous Articles, 



CURIOUS AND INTERESTING EXPERIMENT. 



xjLt Euinbtirgh, Professor Leslie has just succeeded in 

 freezing quicksilver by bis frigorific process. •■ This remark- 

 able experiment was performed in the shop of Mr. Adie, 

 optician, with an air-pump of a new and improvtd construc- 

 tion, made by that skilful artist. A wide thiitp.ometer tube, 

 with a large bulb, was filled wilh mercurv, and .utached to a 

 rod passing through a collar of leathers, from the top of a 

 cylindrical receiver. Tb.is receiver, which was 7 inches wide, 

 covered a deep fiat bason of nearly the same width, and con- 

 taining sulphuric acid, in the midst of which was placed 

 an egg-cup half full of water. The inclosed air being re- 

 duced by the working of the pump to the 5Ulb part, the 

 bulb was repeatedly dipt in the water, and again exposed to 

 evaporation, till ilbecanie incrusted with a coat of ice about 

 the 20th of an inch thick. The cup, with its water still un- 

 frozen, was then emoved, and the apparatus replaced, the 

 coated bulb beine pushed down to less than an inch from 

 the surface of the sulphuric acid. On exhausting the re- 

 ceiver again, and continuing the operation, the icy crust at 

 length started into divided fissures, owing probablv to its 

 being more contracted by the intense cold than the glass 

 which it invested ; and the mercury having gradually de- 

 scended in the ihi-rmomcter tube till it resched ihe point of 

 congelation, suddenly sunk almost into the bulb, the gage 

 standing at the 20ih of an inch, and the included air being 

 thus rarefied about 6' times. After a few minutes, the ap- 

 paratus being removed, and the bulb broken, the quicksilver 

 appeared a sol.d mass which bore the stroke of a hammer. 

 The temperature of the apartment was then 5-4° of Fahren- 

 heit. 



fn another experiment, with a '^niall spirit of wine ther- 

 mometer, under the same circumstances and the same degree 

 of rarefaction, the cold produced was found to be 70i^ below 

 nothing, or more than 30° below the point usually assi"'ned 

 for the congelation of mercury. 



We understand that Mr. Leslie, from the commencement 

 of these inquiries, confidently expected to be able to freeze 

 quicksilver by such a process. In January last year, he 

 maintained a cold within a degree of mercurial congelatiorv 

 durirg the space of eight hours ; but his air pump not being 

 then in iierfect order, and some other parts of the apparatus 

 bemg likewise deieclive, he was induced to defer the txperi- 

 nieni for some time. 



It 



