32 DISEASES CLASS II. 1. 5 1. 



ORDO I. 



Increased Sensation, 

 GENUS V.. 



With the production of new Vessels by external Membranes or 

 Glands, without Fever. 



THE ulcers, or eruptions, which are formed on the external 

 skin, or on the mouth or throat, or on the air-cells of the lungs 

 or on the intestines, all of which are more or less exposed to the 

 contact of the atmospheric air, which we breathe, and which in 

 some proportion we swallow with our food and saliva; or to 

 the contact of the inflammable air, or hydrogen, which is set at 

 liberty by the putrefying aliment in the intestines, or by putrefy- 

 ing matter in large abscesses; all of them produce contagious mat- 

 ter; which, on being inoculated into the skin of another person, 

 will produce fever, or a similar disease. 



In some cases even the matter formed beneath the skin be- 

 comes in some degree contagious, at least so much so as to pro- 

 duce fever of the hectic or malignant kind, as soon as it has 

 pierced through the skin, and has thus gained access to some 

 kind of air; as the fresh pus of a common abscess; or the putrid 

 pus of an abscess which has been long confined; or of cancerous 

 ulcers. 



From this analogy there is reason to suspect that the matter of 

 all contagious diseases, whether with or without fever, is not in- 

 fectious till it has acquired something from the air: which, by 

 oxygenating the secreted matter, may probably produce a new 

 acid. And, secondly, that in hectic fever a part of the purulent 

 matter is absorbed; or acts on the surface of the ulcer; as va-' 

 riolous matter affects the inoculated part of the arm. And that 

 hectic fever is therefore caused by the matter of an open ulcer; 

 and not by the sensation in the ulcer independent of the aerated 

 pus, which lies on it. Which may account for the venereal mat- 

 ter from buboes not giving the infection, according to the experi- 

 ments of the late Mr. Hunter, and for some other phenomena 

 of contagion. See Variola discreta, Class II. 1. 3. 9. 



SPECIES. 



1 . Gonorrhoea venerea. A pus-like contagious material dis- 

 charged from the urethra after impure cohabitation, with smart- 



