1807.] 
valis does alfo, hence it has been inferred 
that the aninval, by this act, formed its 
own tomb, fince it could no longer def- 
troy the wood in which it was contained. 
Mr. Home, however, has fowd that in 
the teredo gigantea, death is not the con- 
fequence of this feclufion from the fub- 
itance in which it is imbedded. He has 
adduced a variety of facts to prove that 
this teredo when arrived at its ful! growth, 
or when prevented from increaling its 
length, clofes up the end of its fhell and 
lives a long time afterwards, furnifhed 
with food from the fea-water which it re- 
ceives like the aétinie. 
The teredines in their anatomicad 
ftructure are more perfect than many of 
the vermes, and have a portion of red- 
blood. They turn round in their fhell, 
with which the body has no attachment, 
and with which their covering only has a 
flight conneétion, at one particular fpot, 
tg prevent the external tubes from being 
diftarbed. This motion of the animal 
Is for the purpofe of boring. Their moft 
ftriking peculiarities are having three ex- 
ternal openings inftead of two: the fto- 
mach beimg unutually large and the brea- 
thing-orgzns having an uncommon con- 
formation, As the teredo gigantea 
bores inthe mud, on which it cannot be 
fuppofed to fubtili, itis become a queftion 
whether the *sredo navalis receives its 
fupport from the wood it deftroys, or 
is fupplied with food from the fea.. 
Mr. Home produces arguments and 
faéts in defence of the laft opinion, fup- 
poling that it forms its habitation in a 
jubftance from which it receives no part 
of its fultenance: 
conv#yed through the inteftines ts not 
digefted, particularly as that examined 
by Mr. Hatchet had not undergone the 
fighteit change: when burnt, the fmoke 
had the odour of Wood ; and it formed a 
charcoal eafily confumed, and was con- 
verted into white afhes in every refpect 
like vegetable charcoal. The tiraight 
courfe of the inteitine in the teredines 
makes it probablé that the faw-dutt re- 
tards the progrefs of the food, fo as te 
render corfvolutions unneceflary. In 
fome of the actinee the inteltine is fo 
much convoluted, that it appears to be 
wound round acentral cylinder, in clofely 
compacted turns. 
SOCIETY OF ARTS, COMMERCE 
- AND MANUFACTURES, 
} HE gold medal has been awarded to 
& Dr. Cocay of Bath, for his Invention 
9. a Drag for railing the Bodies of Pere 
Proceedings of Learned Societies. 
and that the faw-duft » 
367 
fons who have funk under Water.. Inhis 
defeription the mventor fays that he 
diflikes the conttruction of drags hitherto 
in ufe both inthis, and in othercountries. 
Thofe ufed in Holland cannot without 
much danger be appled tothe naked 
body, and are applicable only in cafes in 
which the fubjects fall into the water 
with their cloths on. The drag ufed 
in London is clumfy and dangerous. To 
remedy thefe defects Dr. Cogan has in- 
vented two drags ; of which one is recom- 
mended on account of its cheapness; 
the other is applicable to every cate and 
is fo conttructed as to multiply the chan= 
ces of laying a fecure hold of any part of 
the body without the pofiibility of an in- 
jury. ‘* Had the dimentions,” fays Dr. 
C, ‘“‘ been fmaller than they are, the drag 
would not encompafs every part of the 
human body; and without the partition 
and curvatures at the extremities, the 
diftances would be too great, and the 
body of a child might fall through the 
sintermediate {paces. By means of the 
fliding hooks at the ends, the infirument 
is adapted both to naked bodies, and 
thofe which are clothed. As bathers are 
naked, the fharp-pointed extremitiés 
might lacerate, in adifagreeable manner, 
or, by entering the {kin, they might im- 
pede a firmer hold. They are, therefore, 
made to recede.” 
The upper extremities are made both 
with a focket and a loop to be ufed either 
with a pole or cord, or with both which 
are preferable to either fingly, becaufe 
it has been proved by experiment, that 
a cord tied to the ring or loop, and paf- 
fing through a hole made at the upper 
end of the pole gives a double advantage. 
The drag with a pole attached to it may 
be projected feveral yards further than 
without it; and in drawing forward 
the drag, till the end of the pole is brought 
within reach of the hand, the fubject may 
be raifed above the furface of the water 
in the moft proper direction. 
“We have not,” fays Dr. Cogan, as 
yet had an opportunity of trying thefe 
drags on the human booy; but upon an 
ethyy made in every refpect as like as 
poffible in form to the human body, 
both clothed and unclothed, they have 
anfwered in the moft fatisfactory manner. 
The ettigy was brought to the furface in 
various directions, without once tipping 
from the hold. I fhall add, that with 
two drags and a boat, aliftance given in 
time would almoft enfure fuccefs. A 
hock catching a fingle thread, will, # is 
well known, be fufficient to bring a hu- 
es ira 3A _anan 
