203 DISEASES CLASS II. 1. 3. 10. 



become hereditary. Which incapacity of receiving a second time 

 the small-pox may be explained from the general law of anima- 

 tion, that stimuli greater than natural lose their effect by habit, 

 or from their being too violently or too frequently applied. 



As the cow-pox is said to be so favourable to infants, great 

 benefit might accrue to mankind by their early inoculation, 

 which might in time exterminate the small-pox. This might 

 be perhaps effected by establishing a dispensary in towns, and 

 even villages, and allowing a premium of a few shillings to every- 

 one of the poor who should be thus inoculated, as well as their 

 daily sustenance for eight or ten days, that their arms might be 

 inspected by a surgeon, to ascertain that they underwent the 

 genuine disease. 



10. Rubeola irritata, morbilli. The measles commence with 

 sneezing, red eyes, dry hoarse cough, and are attended with sen- 

 sitive irritated fever. On the fourth day, or a little later, small 

 thick eruptions appear, scarcely eminent above the skin, and af- 

 ter three days, changing into very small branny scales. 



As the contagious material of the small-pox may be supposed 

 to be diffused in the air like a fine dry powder, and mixing with 

 the saliva in the mouth to infect the tonsils in its passage to the 

 stomach; so the contagious material of the measles may be suppos- 

 ed to be more completely dissolved in the air, and thus to impart 

 its poison to the membrane of the nostrils, which covers the sense 

 of smell; whence a catarrh with sneezing ushers in the fever; 

 the termination of the nasal duct of the lachrymal sac is subject 

 to the same stimulus and inflammation, and affects by sympathy 

 the lachrymal glands, occasioning a great flow of tears. See 

 Sect. XVI. 8. And the redness of the eye and eyelids is pro- 

 duced in consequence of the tears being in so great quantity, 

 that the saline part of them is not entirely reabsorbed. See 

 Sect. XXIV. 2. 8. 



The contagion of the measles, if it be taken a sufficient time 

 before inoculation, so that the eruption may commence before 

 the variolous fever comes on, stops the progress of the small-pox 

 in the inoculated wound, and delays it till the rneasle-fever has 

 finished its career. See Sect. XXXIII. 2. 9. 



The measles are usually attended with inflammatory fever with 

 strong pulse, and bear the lancet in every stage of the disease. 

 In the early periods of it, venesection renders the fever and 

 cough less; and, if any symptoms of peripneumony occur, is 

 repeatedly necessary; and at the decline of the disease, if a 

 cough be 'left after the eruption has ceafied^ and the subsequent 

 branny scales aie falling off, venesection should be immediately 

 used; which prevents the danger of consumption. At this time 



