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VI. Objervatlons an certain horny Excrefcences of the Humana 
Body . By Everard Home, EJf F. R. $. 
HE hiftory of difeafes belongs not properly to the pro- 
vince of the naturalift or philofopher ; it is intimately 
connected with the inquiries of the phyfician and anatomift ; 
but when difeafe becomes a caufe of the formation of parts 
fimilar to others exifting in nature, but rendered uncommon by 
novelty of fituation, or produced in animals to which they are 
not naturally appropriated, it may be confidered as having in- 
ftituted a monftrous variety, highly deferving of attention from 
the naturalift. 
To defcribe fuch varieties is indeed more fully the office of 
natural hiftory than of medicine ; but the inveftigation of dif- 
eafes which are found to fubvert the ordinary laws of nature 
refpeCting the fituation or production of parts in an animal 
body, undoubtedly belongs to the medical practitioner. 
By thefe, confederations I have been induced to lay before the 
Royal Society the following account of a difeafe which occurs 
fometimes in the human body, very remarkable in its effeCts, 
but very little underftood as to its caufe ; namely, the pro- 
duction of an excrefcence fimilar to a horn. So curious a phe- 
nomenon has naturally attracted the attention of the ignorant 
as well as the philofopher; and the individuals who have had 
the misfortune to be fubjeCt to this difeafe have been confidered 
as m on fters. - 
Horny excrefcences arifing from the human head have not 
only occurred in this country, but have been met with in fe- 
Read February 17, 1791. 
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