C 7 ] 
is at ioo degrees J, we may conclude, that the open? 
air, heated to that degree, will be fuffer’d with lefs- 
uneafinefs y than when it is fo confined. 
6. That medicines, for whofe operation a pretty 
high degree cf heat is" neceffary, cannot be taken 
iafely, where the heat is very variable, tho’ it fhould 
not be lefs than the degree requifite for the work- 
ing of fuch medicines. Thus a mercurial falivation 
may be carried on fafely, where" the heat is kept 
from 66 to 72 degrees ; but, were the heat fuddenly 
to vary 15 or 20 degrees, the change would be dan- 
gerous* tho’ the heat was not to fall below 66 de- 
grees. 
7. That the body is fometimes differently affedledj, 
according to the different conftitutions of the air $ 
tho’ the air remains the fame, fo far as we can judge, 
with regard to heat, humidity, and gravity. 
8- That, when the thermometer is high, our bo- 
dies are very fenfible of a fmall addition of heat : 
but it is uncertain, whether this proceeds from the 
heat being near the greateft degree we can bear ; 
or, that a greater proportion of heat is requifite to 
raife the thermometer the fame number of degrees 
after it is high, than when it is low. If this be the 
cafe, then, in graduating the thermometers, the de- 
grees ought to be marked fhorter, proportionally to 
the height of the mercury ; but in what proportion, 
is not yet difeovered* I am, & V. 
Edinburgh, Oft. 3. 
1750. 
} Martin’* EfTay*. 
Table 
