THE EARTH. 279 



juniper, if we may credit the ancients. Those 

 who walk through fields of poppies, or in any man- 

 ner prepare those flowers for making opium, are 

 very sensibly affected with the drowsiness they 

 occasion. A physician of Mr Boyle's acquaint- 

 ance, causing a large quantity of black hellebore 

 to be pounded in a mortar, most of the persons 

 who were in the room, and especially the person 

 who pounded it, were purged by it, and some of 

 them strongly. He also gathered a certain plant 

 in Ireland, which the person who beat it in a mor- 

 tar, and the physician who was standing near, 

 were so strongly affected by, that their hands and 

 faces swelled to an enormous size, and continued 

 tumid for a long time after. 



But neither mineral nor vegetable steams are 

 so dangerous to the constitution, as those pro- 

 ceeding from animal substances, putrefying either 

 by disease or death. The effluvia that come 

 from diseased bodies, propagate that frightful 

 catalogue of disorders which are called infec- 

 tious. The parts which compose vegetable va- 

 pours, and mineral exhalations, seem gross and 

 heavy, in comparison of these volatile vapours, 

 that go to great distances, and have been describ- 

 ed as spreading desolation over the whole earth. 

 They fly every-where; penetrate every-where; 

 and the vapours that fly from a single disease 

 soon render it epidemic. 



The plague is the first upon the list in this class 

 of human calamities. From whence this scourge 

 of man's presumption may have its beginning, is 

 not well known ; but we know that it is pro- 



