.324 



J 



DISEASES 



Sect. XIV. i. 6. 



a 



malt 



d may b 



fily mad 



ketable and equally 



t^ood ; for the livin? ?rairi will not abforb much water in a (h 



to 



to to 



may be mixed with clean fand, and after being well ag 



ted th 



d 



ay be feparated 



ddl 



d if neceffary 



fame find may be wadded and dried for repeated ufe. 



6. Befides the four internal difeafes above fpoken of, as mentioned 

 by Linneus ; and the uredo of Mr. Lan:ibcrt, there are probably many 

 others, which have not yet been fufficiently attended to, as the caii- 

 ker, c^ano-rena ; the honey-fvveat, exfudatio mellita ; the miliary 



fweat, exfudatio miliaris ; the fap-flow, fluxus umbiiicalis ; and the 

 jm fecretion, fecretio gummofa. 

 The canker, which may be termed gangrena vegetabilis, is a pha- 



to 



edenic ulcer of the bark ; which is very deftrudive to appl 

 nd pear-trees, as it fpreads roui 



dth 



k or bi 



dd 



flroys them. 



Mr. Knisht has obferved this difeafe to be mofl frequent and fatal 



thofe 



the fruit of which has been long in falh 



they 



have been perpetually propagated for a century or two by ingraft 

 which he believes to be a continuation of the old 

 ri(hed by a new flock ; and that the 



thoucrh 



canker is th 



difeafe of old 



arifes 



age, like th@ mortification of the hmbs of elderly people, and ar 

 from the irritabihty of a part of the fyflem . 



But it feems more probably to be an hereditary difeafe, as the buds 

 of trees being a lateral progeny, and more exadlly refembling their 

 parents, muft be more liable to the difeafes gradually acquired or in- 

 creafed by the influence of foil or climate ; and have not the proba- 

 bility of impravement, which attends the progeny of fexual genera- 

 tion. 



It is neverthelefs frequently produced on trees by external violence, 



as by a flroke with a fpade by a carelefs labourer, who is digging near 

 them ; but this probably may more eafily affed the old grafts above 



mentioned. When a deftrudion of the bark is thus produced by ex- 



H 



ternal 



