New Publications, 2JX 



fame ; but it is obtained in the grei^ten; quantity by means of 

 metals. There are i'oTuc, however, by niiiiins of which you 

 extra6l only azotic gas, becaufe they feize on all the oxygen 

 of the nitrous acid employed. The flafk made ufe of to 

 caufe the acid to cxercife an action on the metal ought to be 

 cijtirely filled with the former, becaufe, if any air were left in, 

 the gas in difengaging itfelf would combine with the oxygen 

 of the piire air, and this combination, diflblving in the 

 Jiquor, would occafion a vacuum which would permit the 

 water of the tub to pal's into the flafk. 



*^ Nitrous gas is a little heavier than atmofpheric air : its 

 fpecific gravity is to that of air as 105*35 is to 100, and to that 

 of dillillcd water as 33*0179 is to looco. A cubic inch of 

 this fluid weighs 0*4860; and the cubic foot i ounce 3 

 drams 48 grains*. 



^' Nitrous gas, wlien very pure^ is not foluble in water; 

 as may be eafily proved by agitating it in that liquid. 



*' It gives no fjgn of acidity, as it does not redden blue ve- 

 getable colours; nor does it combine with alkalies unlefs.it 

 be mixed with air, for it then becomes acid by fejzingou the 

 t)xygen of the air. 



<* Nitrous gas fpeedily deftroys plants and animals im- 

 merfed in it ; and it extinguishes burning bodies, firft making 

 the flame afllime a green colour. 



^' If nitrous giiS be mixQd with atmofpheric air, it becomes 

 red, and has, the odour of nitrous acid; as may be ealily 

 proved by diflufing a little of it through the air: it then ab- 

 forbs the oxygen of the air, combines with it, and becomes 

 nitrous acid. This may be better fliovvn by the following 

 experiment : — Put two meafurcs of atmofpheric ^ir and then 

 one of nitrous ga» into a.glafs tube marked in equal divifions 

 with a diamond : the mixture will immediately become red 

 and grow hot; and as this combination, which is really 

 nitrous acid, is very foluble in water, you will fee the water 

 nfccnd in the tube in proportion as the mixture dilfolves iri 

 it, fo that of the 3 mcafures about i | will be diffolvtd, if 



* According to the new Fiench fvTtcm, a cubic dcctmctrt- of th s flu d 

 tK'cighs I ijrammd 30*1 inill«gramtr;t.s j and a cubic iilttre, i chi.iognin.mc 

 •301 giammts 335 niillijjrammes. 



' the 



