capacity of receiving the aétion of ftimuli. 
is increafed by the effect produced from 
the application of the fedative cold ; for, 
1. The fedative effeét of cold diminifhes 
all the a€tions of the body ; 2. It dimi- 
nithes the temperature ; 3. It diminifhes 
the a&tion of the heart and arteries in the 
firt inftance, by rendering them quick and 
feeble, in the fecond by rendering them 
flow and feeble; 4. Its effeéts are expe- 
rienced more readily by adult than by 
young animals ; 5. Animals of an infe- 
rior temperature, whole excitability is 
abundant, can fubfift under lower degrees 
of this power than warm-blooded animals, 
or thofe whofe excitability is not fo abun- 
dant ; 6. Animals expofed to its effects 
have their capacity to receive the action 
of {timulants increafed. 
Hence it is inferred by Dr. A., thata 
power which diminifhes the a€tion of the 
heart and arteries, the energy of the brain, 
and increafes the excitability of the fyftem, 
is afedative. It is alfo inferred from the 
experiments, as a final conclufion, that the 
appearances exhibited by the animal body 
under the influence of opium are direétly 
analogous to thofe exhibited under the ac- 
tion of ether and fpirits of wineand yola- 
tile alkali ; that as thefe powers are {fti- 
mulant, fo in like manner, and depending 
upon equal proofs, is opium a ftimulant. 
Mr. Gipson has laid before the Man- 
ehefter Society a Paper on the Ufe of Su- 
tures in the Skulls of Animals. He ob- 
ferves, that of the many ufes attributed to 
them, fome are totally erroneous 5 fuch as 
that for allowing the tranfpiration of moif- 
ture, to keep the brain cool and fit for 
thinking ; for admitting a more free com- 
munication by blood-veflels between the 
external and internal parts of the head ; 
or for affording interftices, that the bones 
may be pufhed afunder by the growth of 
the brain, left that organ fhould be cramp. 
ed in its growth, in confequence of the 
comparatively flow growth of the bones 
of the fkul]. Ocher ufes attributed to the 
futures, are advantages derived from their 
ftruéture, which are enjoyed in early in- 
fancy, or till adult life, but gradually 
ceafe after that period. “Thus at the time 
of birth the loofe unicn of the bones of the 
ikull accommodates the fhape of the head 
to the figure of the different parts of the 
cavity through which it pafits: Atadult 
age, when the futures are formed, they 
may check the progrefs of a frafture ; or 
vibrations communicated to the bones of 
the fkull will be propagated with lefs 
force to the brain, in confequence of the 
bones being (eparated at the futures. 
Proceedings of Learned Socicti¢se 
It is however evident to Mr. G., that 
thefe are not the main purpofcs for which 
the futures are formed ; otherwife they 
would not begin to be obliterated at a pe- 
riod of life when they would perform their 
offices more ufefully thanever. The true 
purpofe for which they are formed, and 
the particular procefs with which they are 
conneéied, is fully completed before their 
obliteration takes place. 
Such is Mr. Gibfon’s theory ; and he 
fays, that in almoft all the bones that do 
not admit of motion, the cartilage and 
periofteum, which was once isterpofed, is. 
in time obliterated, and the different por- 
tions coalefce. It appears alfo that the 
bones of the body are increafed in length, 
not by an uniform extenfion of the whole 
fubftance, but by an addition of bony 
matter in fome particular part. Thus the 
bedy of a cylindrical bone is lengthened 
by. addition to each end. Hence it may 
be inferred that the fame general plan is 
purfued in the extenfion of the fiat bones 
of the body, which is effe&ted by additions 
to their edges, and of courfe that the bones 
of the fkull are increafed in extent by the 
depofition of offeous matter at their edges, 
or where they are joined together by fu- 
ture. For this purpofe it is neceflary that 
they fhould be retained at a certain dif- 
tance from each other, that the periofteum 
with its veffels may pafs down between 
them, free from compreffion, and fecrete 
the ofleous matter. At the fame time the 
thin bones compofing the upper part of 
the fkull, refting as an arch upon its bafis, 
muft be united together fo firmly, as not 
to be feparated by common degrees of vi- 
olence. For this purpofe projecting points 
from the external furface of each bone are 
reciprocally received into correfponding 
niches which only penetrate through one- 
half of the thicknefs of the fkulJ, and 
form an irregular kind of dove-tailing. 
Thus the projeéting points from each 
fide, refting upon the falid furface of the 
oppofite bone, can refift more effeétually 
any violence which might tend to force 
the bone inwards ; and the internal part 
of the fkull prefents, by this means, a 
{mooth furface to the coverings of the 
brain. Hence the futures of the human 
fkull, by their formaticn, at once unire the 
bones together, and fo far feparate them, 
as to allow tne interposition of a vafcular 
organ, by which their fuperficies is gradu- 
ally increafed toits greateft extent, This 
explanation of their ufe acccunts for the 
fironger adhe“on of the dura mater inter- 
naly, and periojeum externally, than ‘ia 
cther parts ef the fkull, becaufe thefe 
membranes 
