28 INCITANTTA. ART. II. 2 . 4. r. 



with the blood in the lungs evinces, that it muft act as a ftimu- 

 lus to the fanguiferous fyftem, as the motions of the heart and 

 arteries prefently ceafe, when animals are immerfed in airs 

 which pofTefs no oxygen. It may alfo fubfequently anfwer 

 another important purpofe, a"s it is probable that it affords the 

 material for the production of the fenforial power ; which is 

 fuppofed to be fecreted in the brain or medullary part of the 

 nerves ; and that the perpetual demand of this fluid in refpira- 

 tion is occafioned by the fenforial power, which is fuppofed to 

 4be produced from it, being too fubtle to be long confined in any 

 part of the .yftem. 



Another proof of the ftimulant quality of oxygen appears 

 from the increafed acrimony, which the matter of a common 

 abfcefs pofiefles, after it has been expofed to the air of the at- 

 mofphere, but not before ; and probably all other contagious 

 'matters owe their fever- producing property to having been con- 

 verted into acids by their union with oxygen. See Clafs II. i. 8. 



As oxygen penetrates the fine moid membranes of the air-vef- 

 fels of the lungs, and unites with the blood by a chemical at- 

 traction, as is feen to happen, when blood is drawn into a bafon, 

 the lower furface of the crafiamentum is of a very dark red fo 

 long as it is covered from the air by the upper furface, but be- 

 comes florid in a ihort time on its being expofed to the atmof- 

 phere ; the manner of its introduction into the fyftem is not 

 probably by animal abforption but by chemical attraction, in 

 which circumftance it differs from the fluids before mentioned 

 both of heat and electricity, and of ether and efTential oils. 



As oxygen has the property of pafTmg through moift animal 

 jnembranes, as firft difcovered by the great Dr. Prieftley, it is 

 probable it might be of ufe in vibices, and petechise in fevers, 

 and in other bruifes ; if the ikin over thofe parts was kept moift 

 by warm water, and covered with oxygen gas by means of an 

 inverted glafs, or even by expofing the parts thus moiftened to 

 the atmofphere, as the dark coloured extravafated blood might 

 thus become florid, and by its increafe of ftimulus facilitate its 

 reabforption. 



Two weak parients, to whom I gave oxygen gas in as pure a 

 Hate as it can eafily be produced from Exeter manganefe, and 

 in the quantity of about four gallons a day, feemed to feel re- 

 freihed, and ftronger, and to look better immediately after ref- 

 piring it, and gained ftrength in a fhort time. Two others, 

 one of whom laboured under confirmed hydrothorax, and the 

 other under a permanent and uniform difficulty of refpiration, 

 were not refreshed, or in any way ferved by the ufe of oxygen in 

 the above quantity of four gallons a day for a fortnight, which 



