570 SUPPLEMENT 
M. Tilesius writes thus concerning the physaliz: all the 
physaliz consist of along bladder inflated with air, floating 
on the water, having upwards a sort of comb, which answers 
as a sail, and underneath some long tentacula, which consti- 
tute at once the mouth and helm. Although to examine 
these is difficult enough, because they burn more strongly than 
nettles, when they are touched, he has been enabled to dis- 
tinguish three different kinds at least, on separate individuals. 
M. Tilesius has made most observations on the sting pro- 
duced by touching these animals. He ascertained that the 
burning sensation which is felt, when one has touched more 
or less strongly the tentacula of a living physalia, and which 
is more intense than that produced by nettles, is owing, not 
to a mucous matter which covers them,.as he had supposed 
at first, but to some little hairs of a rose colour, which the 
mucosity introduces into the pores of the skin. In fact, one 
day when he was severely burned by handling too much 
the tentacula of a physalia, after having tried without success 
to calm the pain, with vinegar, solution of salt-petre, salt, 
sulphuric or ammoniac acid, he only achieved the point by 
frequent lotions of soap and water on the affected parts, hav- 
ing previously carefully taken out the little hairs with a 
tweezers. We must, nevertheless, believe that the mucous 
matter itself also possesses this burning property; for the 
same observer found, that on washing himself in a porcelain 
vase, in which a physalia had been preserved, and which had 
not been sufficiently cleaned, his lips, nose and cheeks, were 
severely burned. 
The physaliz live in the waters of the sea, at tolerably great 
distances from the shore; except when they are driven thi- 
ther by currents, or by the wind. Observers not having seen 
them, except at the surface, it has been generally admitted 
that they are always there, the bladder being partly out of the 
