L 143 ] 
mer purity as foon as the leaves are 
produced. And this is what Abbé 
Fontana found to be a conftant 
fa&t 
If I had more leifure, I fhould be 
inclined to expatiate in a wide and 
open field of reflections, which pre- 
fent themfelves to my mind, ‘and to 
draw all the confequences which 
feem to flow, as from a fountain- 
head, from the already mennones 
obeeraitbiees: 
Is it not probable, that thofe 23 
labour under confumptive and afth- 
matic complaints, and who find the 
greateft relief, and fometimes a per- 
fect cure, by retiring to mild cli- 
mates, where vegetation is lively, 
aud begins fooner in the fpring, 
fhould go to fuch places where the 
conftitution of the air is found by 
sae to be during the whole 
year 
