£44 Mr Black adder on Circu mstances connected with the 
alone of a horizontal piece of metal is coated with condensed 
vapour; but, if it has been lying on the grass, both its' sides may 
be moist. 
Instances of the third variety of ways in which polished metals 
may acquire moisture after sunset, are much less familiar than 
either of the former ; — and, indeed, can seldom be observed 
without some trouble, self-denial, and even risk. Few things of 
the kind being more injurious to the health of persons accus- 
tomed to the usual refinements of life, than lengthened exposure 
in the open air on such nights as are most fitted for making ex- 
periments and observations on the spontaneous condensation of 
moisture. There can be little doubt, that the persevering and 
ingenious Dr Wells injured his health not a little by the unwea- 
ried ardour with which he prosecuted his favourite pursuit ; and 
that too, according to his own account, under very disadvanta- 
geous circumstances. 
When a piece of polished metal is placed on grass, whose 
temperature is already considerably reduced below that of the 
air at a short distance above the ground, if its size is not consi- 
derable, or if the cold of the grass is great, relative to the tem- 
perature of the subjacent soil, the piece of metal will also be- 
come somewhat colder than the air a short distance above it, and 
the more speedily, if repeatedly moved to different parts of the 
grass. Again, if a piece of polished metal be suspended in the 
air, a short distance above the grass, after, or until the latter 
has had its temperature considerably reduced, the metal will ac- 
quire the temperature of the air in contact with it, and this being 
colder than the air a few feet from the ground, so also must the 
piece of metal be colder than the air at that height. Here, 
then, we have two instances of polished metals becoming colder 
English. Now, there are two ways of ejecting the saliva, the one practised by 
those who have but little, the other by those who have rather a superfluity of that 
fluid. If, then, we attend to climate, in as far as that has a tendency to pro- 
mote the cutaneous more than the mucomembranous discharges, and vice versa , 
and if we apply this to the case of Greece and Britain, we may be led to infer, 
that one mode of ejecting the saliva would be most common in the one country, 
and the other {at the time the word was first used,') in the other. Hence the ori- 
gin, perhaps, of two words which, though very different in sound, nevertheless 
exactly imitate the same action. Such is Etymology ! 
