CHEMICAL SCIENCE. 171 



Chlorine cannot be liquefied by means of ether cooled to —3-1° C. ; 

 but when liquid sulphurous acid is substituted for ether in the fore- 

 going experiment, considerable quantities of liquid chlorine may be 

 obtained. 



A m mow !a may also be obtained in the liquid state by means of 

 cooled sulphurous acid ; the minimum temperature of which is 

 — 50°, while liquid ammonia boils at— 35° '7. 



When liquid ammonia is used as a cooling agent, by rapidly eva- 

 porating it under the air-pump in the presence of sulphuric acid, a 

 temperature of —87° C. is attained ; the limit of the lowering of the 

 thermometer is determined by the total solidification of the ammonia. 

 By this temperature Loir and Drion are able to liquefy carbonic acid 

 under the atmospheric pressure. They have also prepared liquid 

 carbonic acid by heating bicarbonate of soda placed in one of the 

 branches of a sealed tube. On cooling, the carbonate of soda re- 

 absorbs the carbonic acid gas. 



The authors intend to investigate the physical and also chemical 

 properties of the liquid gases prepared at these low temperatures ; 

 under these conditions the ordinary affinities are greatly modified. 

 For instance, 20 cubic centimetres of liquid ammonia placed on a 

 quantity of concentrated sulphuric acid, showed no action at first. 

 Gradually an action was set up and the liquids combined, but with 

 much less violence than might be expected. 



The temperatures were measured in these observations by means 

 of an absolute alcohol thermometer, the fixed points of which were 

 determined by means of the temperature of melting ice, and of that 

 of about two pounds of frozen mercury. The temperature of the 

 latter was assumed to be —40° C. — Philosophical Magazine, 

 No. 132. 



OSMIUM. 



Peofessoe T. W. Mallet, in a paper communicated to Silliman's 

 Journal, observes : — 



The specific heat of Osmium, so far as its value as a physical 

 character goes, opposes the introduction of this element into the 

 arsenic group. It has been determined by Kegnault= "03063 ; 

 multiplying now by the equivalent 97, we have the product 2 - 97H, 

 thus placing osmium in the list of the elements (including the 

 majority) for which the product of specific heat by atomic weight is 

 nearly 3 ; while for phosphorus, arsenic, antimony, and bismuth, the 

 product thus obtained is twice as great, or about 6. In this re- 

 spect, however, osmium probably resembles nitrogen — the latter ex- 

 amined, as it necessarily is, in the gaseous form. 



It is to be hoped that the conducting power for heat and elec- 

 tricity of compact osmium will soon be examined; nothing is as yet 

 known of these characters. 



Lastly, as regards the magnetic relations of the element : it is 

 placed, with some doubt, by Faraday in the paramagnetic class ; 

 the metal and its protoxide were found to act feebly in this sense, 

 while pure osmic acid is said to have shown itself clearly diamag- 



