%y-2 Keiu PuhlJcafions, 



the air be of a good quality. What remains under the ga^ 

 fcous form is nothi»g but azotic gas. The heat produced on • 

 ibis ocCalion is owing to the caloric of thcfe fluids, which ^ 

 klfumes tlic free (late. If, inftead of atmofpheric air, you'* 

 mix pure air with tlx? nitfous gas, '^ix. two mcafurcs ot gas 

 and one of pure air, the rcdncfa will be much rnbre intenfe, ' 

 the heat protluccd far greattT, and ih'e njixture. ivill bealmqft"-^ 

 entirely diflTolvcd in the water. '■ ' »• ; ' -> 



" It may be here fecn, that by means of thi-s- gas we can \ 

 afccrtain the falubrity of the air 3 for it combines Only with ' 

 oxygen, or the bafe of pure air, which is the only rcfpirable 

 part of the atmofpherc. Air fubje6led to this tcft ought * 

 therefore to be coniidered as fo much fitter for rcfpi ration, ^^ 

 according as the quantity of it abforbed is greater. ' '^* 



*' The water in which this mixture of nitrous gas and pure - 

 air is diflblved, becomes liquid nitrous acid ; fo much the 

 lironger the lefs it contains of water, ift. It reddens blue- 

 vegetable colours j it is therefore acid : 2d, This acid .unites 

 and combines with alkalies, and forms with them dctonatingi 

 nitres: it is therefore nitrous acid. To prove this, affix to' 

 the bottom of a bell-glafs fome concrete carbonat of ammonia# 

 tred up in a fmall piece of gauze, afid place the bell on the 

 flielf of a pneumatic tub in fuch a manner that the bell may 

 be two-thirds filled with atmofpheric air, while the otlier 

 third contains water. If you thcti make nitrous gas to pafs 

 into the bell, the mixture w'ill immediately aflumc a red co- 

 lour: an etfccl; produced by the combination of the gas with 

 the refpirablc part of the air. By this combination the gas 

 has become nitrous acid. You will then perceive a great 

 cleal of whil-e vapours arifing from the combination of this 

 acid with the carbonat of ammonia. Thefe vapours arc af- 

 terwards coiulenfed, and cryftallife. The crvftals collected 

 will fufe on burning coals, and therefore are nitre. 



*' Oxygenated Muriatic Gas, 



** Oxygen&ledm^iriatic grYs, the dephlogifticated muriatie 

 acid of S.chcelc.^ujder.ii gafeous form, is the muriatic acid 

 gas, of- which \ve fliall fpeak hereafter, but furcbargcd with 

 oxygon and perfectly dephlegmated. 

 -■''' 8 <^ This 



