NITROUS OXIDE. 153 



increases all the secretions, but is not eniplovrd with ti 



in view. It is believed by some to diminish the liability to 



gall stones, or actually to dissolve concretions already formed. 



NITROUS OXIDE. N 2 O. (Not Officinal) 



Nitrous Oxide Gas, Protoxide of Nitrogen, " Laugh- 

 ing Gas." 



Source. Made by heating Nitrate of Ammonia. NH 4 N0 3 = 

 N 2 + 2H 2 0. 



Characters. A colourless inodorous gas. It is provided for 

 use condensed into a liquid, in strong iron bottles, whence it is 

 allowed to escape into" a caoutchouc bag. 



ACTION AND USES. 

 1. ACTION ON THE BLOOD AND ITS USES. 



Nitrous oxide gas, administered from an inhaler, rapidly 

 enters the circulation ; is absorbed by the plasma ; converts 

 the arterial into venous blood, in the course of about sixty 

 seconds; and thus produces partial asphyxia. It does so 

 apparently by diminishing the amount of oxygen in combi- 

 nation with the red corpuscles, without itself uniting with 

 the haemoglobin, like CO and NO ; in this respect it is an 

 " indifferent " gas, like N and H, simply taking the place of the 

 oxygen, if this be completely excluded at the same time, and 

 exerting of itself no poisonous action upon the corpus, ', 

 must, therefore, be given pure, i.e. without any admixture of air. 

 The effect of the incipient asphyxia, and the uso to which it 

 may be turned, will be described in the next section. 



2. SPECIFIC ACTION AND USES. 



Nitrous oxide gas not only renders the blood venous, but 

 simultaneously enters the nervous cent ITS, upon which it a< ;s, 

 first as a stimulant, and speedily as an anaesthetic. Thus the 

 gas produces a series of phenomena which can he resolved into 

 ,-illel effects of venosity of the blood or asphyxia, and a 

 specific influence on the nerve cells of the convolutions. 

 a few seconds' excitement, the subject for anaesthesia by nit runs 

 oxide begins to breathe laboriously ; the mind Incomes rapidly 

 obscured ; and by the end of about sixty seconds . 

 is lost, the face may be livid and bloated in appearui'e, 

 respiration becomes stertorous, muscular twitching* occur, the 

 pulse fails at the wrist, and the whole appearane.> i- alam. 

 novice. If the inhalation be now interrupt! <;. 



