40 ANIMAI. PAEASITES 



tJie blood, irritating salts, melancholic juices, and 

 special fermentation, — the presence of the itch- 

 mite, when admitted, being accounted for by 

 equivocal generation. These observers saw and 

 described the insects quite perfectly, found their 

 eggs, and discovered the females laying them, and 

 came to the conclusion that the itch-disease, or, 

 scabies, arose solely from the presence of an ani- 

 mal which is incessantly biting the skin, and 

 thereby causing the patient to allay the itching by 

 scratching. They also explained the contagious 

 character of the affection by the transference of 

 the insects from one individual to another. Be- 

 cause these discoveries were true, they were 

 denied and combated by the medical writers of 

 those days ; yet nearly one hundred and fifty 

 years passed before any better natural history of 

 the mite appeared. King George II.'s physician, 

 Dr. Richard Mead, of London, reported Bonomo 

 and Cestoni's observations to the Royal Society, 

 and published them in No. 283 of the "Philosoph- 

 ical Transactions." 



We have given this little historical sketch to 

 show how old the disease is, and how old a 

 knowledge of its cause is also. Notwithstanding, 



