574 PRACTICE OF PHYSIC. 



In every solid as'well as every fluid substance which makes a 

 part of the human body, there is a considerable quantity of air 

 in a fixed state, which may be again restored to its elastic state, 

 and separated from those substances, by the power of heat, pu- 

 trefaction, and perhaps other causes ; but which of these may 

 have produced the several instances of Pneumatosis and flatulent 

 swellings that have been recorded by authors, I cannot pretend 

 to ascertain. Indeed, upon account of these difficulties, I can- 

 not proceed with any clearness on the general subject of pneu- 

 matosis ; and, therefore, with regard to flatulent swellings, I 

 find it necessary to confine myself to the consideration of those 

 of the abdominal region alone ; which I shall now treat of under 

 the general name of Tympanites. 



MDCXXVII. The tympanites is a swelling of the abdomen ; 

 in which the teguments appear to be much stretched by some 

 distending power within, and equally stretched in every posture 

 of the body. The swelling does not readily yield to any pres- 

 sure ; and in so far as it does, very quickly recovers its former 

 state upon the pressure being removed. Being struck, it gives 

 a sound like a drum, or other stretched animal membranes. No 

 fluctuation within is to be perceived ; and the whole feels less 

 weighty than might be expected from its bulk. The uneasiness 

 of the distention is commonly relieved by the discharge of air 

 from the alimentary canal, either upwards or downwards. 



MDCXXVIII. These are the characters by which the 

 tympanites may be distinguished from the ascites or physconia ; 

 and many experiments show, that the tympanites always de- 

 pends upon a preternatural collection of air, somewhere within 

 the teguments of the abdomen : but the seat of the air is in 

 different cases somewhat different ; and this produces the dif- 

 erent species of the disease. 



One species is, when the air collected is entirely confined 

 within the cavity of the alimentary canal, and chiefly in that of 

 the intestines. This species, therefore, is named the Tympa- 

 nites intestinalis, Sauv. sp. 1. It is, of all others, the most 

 common ; and to it especially belong the characters given above. 



A second species is, when the air collected is not fentirely 

 confined to the cavity of the intestines, but is also present be- 

 tween their coats ; and such is that which is named by r Sau- 



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