RoyalSocietv. 23 1 
mach is chilled, and he is in danger of a flux, and that imme- 
diately : Again, men are not lo careful to guard themielves from 
the air^ for the air here, tho' not fo cold, is much more fubrile 
and piercing than in England, and it corrodes iron looner, but 
not by moiiture, for the air is not fo moift5 in rainy weather 
the mortality is obferved not to be fo great. 
Tl:ie TiijfeBion of a Leech , by Mr. Poupart. Phil. Tranf. 
N^ 299. p. 722. 
THE upper lip of a Leech is firetched out into a point, and 
falls upon the under lip, which is round like a creicenr, 
andfhorter; its throat, on the indde, is covered with a great many 
white mufcles, about 5 or 5 lines long, as large as a fmall thread, 
and lying parallel to each other, along its body j when it applies 
the mouth to the flejfli of any animal, all thele mufcles contra^' 
ing themfelves, it fucks with fo great violence and greedinels, 
that the part becomes of the form of a fiTiall nipple 5 {o that all 
the effect of fuci:ion terminating in a very fmall Ipace, of neceffity 
the fiefh muft break in that part. There is fecn at the extremity 
of its tail, a little flat parr, exactly round, the border of which 
is elevated far above the tail, and all round it; and this it ap- 
plies fo uniformly to the bodies on which it faflens, that it 
touches them in all their parts, and then drawing up a little the 
middle ©f this flat part, without taking off the edges, flie makes 
of it, as it were, a little balm, and leaves a cavity m the middle - 
this excellent glue flicks fo llrongly to the tail of the leech, that 
it IS a hard matter to pull it away without making fbme rent, 
efpecially if you draw it perpendicularly from the furface on 
which the animal is faflened; it has always recourfe to this little 
inflrument, f jr faftening its body, to the end it may not be fuf- 
pcnded in the air, whilft it draws nourifhment by fuction, or 
cjfe that it may not be carried away with the current of water, 
whilli it moves its head to and fro' in learch of food. Its gut 
goes in a flreight line from the mouth to the ^;///5, it is as large 
as a goofe quiil, and all along belet with a great number of lit- 
tie valves- feme of which make a perFefl circle with a hole in 
the middle, iind others a half-moon 3 ff^me are fhaped ipiral-wife, 
and of thefe there is a large one near the tail, falhioned like the 
heart, which leaves only a very little hole, near which is found a 
great deal of yellow fat, which fills all the cavity of the intefline 
to half an inch 5 there are two fmall inteftines or appendixes, 
each half an inch in length, and as large as the feather of a limll 
bird's wing, which open into the great gut, and are fluit at the 
other 
