A N A T 
the healthy ffatd, poffeffes a low degree of fenfibility. 
Theadtual cautery, which, in former periods, was much 
employed by furgeons, is known to produce a fenfation in 
the bone, though faid to be rather pleafant than painful. 
-This, however, is a fufficient proof) that the bones are 
not abfolutely incapable of feeling. But the fenfibility 
of bone is fufficiently obvious in the difeafed ftate : inju¬ 
ries of various kinds will excite inflammation in it, as well 
as in the foft parts ; and we obferve the fame phenomena 
produced in both. An increafed determination of blood 
to the part fwelling, a fpongy loofenefs of texture, fup- 
puration, and ulcer, take place in bone, in a manner pre- 
cifely fimilar to what we obferve in the foft parts. And, 
as in the latter the organization is deflroyed, fo alfo in the 
former we obferve the bone eroded, and difcharged by 
ulceration. During the progrefs of fuch a difeafe, the 
fenfibility of the bone is aftonifhingly increafed. Thus in 
the parts which polfefs the mod acute feeling, we obferve 
the fenfibility increafed by difeafe. In like manner the 
bones, ligaments, burke, and other parts, in which, during 
health, the feeling is fcarcely perceptible, become, by dif¬ 
eafe, extremely fenfible, fo as to give the molt exquifite 
pain in many cafes, fuperior to what is experienced in a 
fimilar difeafe of the foft parts. 
In every view that we can take of the fubjedfc, bone ap¬ 
pears to be as perfectly organifed matter as any other 
part of the body. It receives its Ihare of the fanguiferous 
and abfovbent velfels ; it is fupplied with nerves, and by 
all of them is immediately and intimately conne&ed with 
the fyftem at large. It is produced by the a limalizing 
procefs ; it is liable to difeafe and death ; it is fufceptible 
of impreffions from ftimuli; and by their operation is ex¬ 
cited to arition. Thus the bones are conftrudted upon a 
plan admirably calculated for the purpofe they are in¬ 
tended to'lerve in the body. In order to give them hard- 
nefs and inflexibility, they are chiefly compofed of up 
earthy fait. This fait is depofited by circulating velfels, 
which enter their fubftance ; and when it has remained for 
a certain period, it is abforbed and carried out of the fyf¬ 
tem by velfels deltined fur that purpofe. Thus a conti¬ 
nual depofition and abforption is going on in the bones, 
as well as in any other' part of the body. The nerves 
with which bone is fupplied, are doubtlefs intended to 
fupply the veffels which are ramified through its fub- 
flance ; as we cannot fuppofe that they have any ufe with 
refpredt to the inorganate earthy fait, of which bone is 
chiefly formed. Upon the whole, then, it appears, that 
bone mull be lefs capable of fenfation, and lefs liable to 
be adted upon, than perhaps any other part of the body, 
as it is only the velfels and nerves which belong to it that 
are capable of fenfation. 
Cartilage polfelfes a degree of organization fomewhat 
inferior to that of bone. This fubftance is interpofed be¬ 
tween bones, particularly at the joints, with the view of 
abatingfridlion, and preventing thofe injuries which might 
be expedted from the collifion of the harder bony matter. 
Hence they are fo conftituted as to polfefs a degree, of 
elafticity, by which they yield to the weight of theT body, 
and are reftored to their original fize when that weight is 
removed. Cartilage was at one time fuppofed to be a 
mere concrete, having little or no connedlion with the 
other parts of the fyftem, except by mechanical cohefion. 
But, in the original formation of bone, it appears that car¬ 
tilage is organized matter, and as truly connedted with the 
fyftem as any other part of the animal. Thus we obferve, 
that the bones are terminated at their articulations by a 
thin cartilage; and the periofteum is extended over the 
furface of the cartilage. The circulation in cartilage is 
indeed not very adtive, but fufficient to preferve it in the 
living ftate. Had the powers of life been confiderable in 
cartilaginous matter, had its feelings been acute, it muft 
have produced very confiderable’ inconveniencies to the 
animal: it would have been liable to frequent inflamma¬ 
tion, and other diforders. But, having received a peculiar 
Vol. I, No. 34. 
O M Y. 529 , 
mode of organization, in which the feeling is obfeure, and 
the excitability dull, it is admirably fitted to perform all 
the motions of'the body, and is fubjedted to the fridlion of 
the joints, without being liable to injury. 
The cellular fubftance, like bone and cartilage, pofTefTes, 
a low degree of fenfation, and its excitability is obfeure. 
This matter, tinder various modifications, is employed to 
unite, cover, and defend, the other parts of the fydent¬ 
in all the forms in which it fubtlfts in the body, it po defies 
little fenfibility ; and may, when compared with the muf- 
cularand nervous folids, be alrnoft confidered as inanimate 
matter : that is, when in the healthy ftate, like bone and 
cartilage, its excitability is in a very low degree. Both 
mechanical and chemical ftimulants, when applied to it, 
give but little fenfe of pain. 
Fir ft, the cellular fubftance is extended over the whole 
body, and interpofed between all the parts. Formed into 
an infinite multitude of cells, which contain fat and a thin¬ 
ner fluid, it is happily conftrudled to allow the parts to 
glide and move ealily. It penetrates into the hmfcles, and 
keeps their fibres at a proper diftarice, fo that the adiion. 
of each may be duly exerted. It appears alfo to fupport 
and lubricate the mufcular fibre, infomuch that the ftrength 
of the fyftem in health, and its weaknefs in difeafe, have 
been fuppofed in fome degree to depend upon the proper on 
improper ftate of the cellular matter. It has generally 
been admitted, that the thinner fluid contained in the cells 
is designed to render the play of the fibres eafy and free ; 
and that the fat is intended to fupport the fibres in their 
arition, to lubricate them, and to give a plumpnefs to the 
body. It has alfo been fuggefted, that it may be reab- 
forbed for various ufes in the fyftem. It is probable, 
however, that the febaceous matter, like the phofphate of 
lime in the hones, can only be applied to its proper ufes in 
the fyftem for a certain period. By degrees it becomes 
unfit for the purpoles of the animal economy. It is fe- 
creted and depofited in the cells, and, when reabforbed, is 
probably, with other excrementitious matter, thrown out 
of the fyftem. Secondly, a modification of the cellular 
fubftance is employed as a covering to the bones. The 
periofteum appears to be a condenfation of the cellular 
fubftance applied in fuccefti,ve layers, fo as to produce a 
thick membrane, which conveys the blood-veffels, &c„ 
to the bones. Thirdly, the tendons of the mufcles are 
produced by a mere continuation of the periofteum, from 
which they are evidently derived, and not from the nmf- 
cles, as the old anatomifts imagined. Fourthly, the. ten¬ 
dinous matter fomewhat differently modified, fo as to form 
a thin membranous fheet, is employed to cover the mufcles 
forming the vaginae or fafeite of the mufcles. The cellu¬ 
lar fubftance which lies under the fafeia, and which imme¬ 
diately furrounds the mufcle, appears to be only more 
loofely attached laminae of the fafeia. It is from the fafeia 
that the cellular matter is derived which penetrates into 
the mufcles. Fifthly, the periofteum, formed into a 
thicker membrane, and ftrengthened by the adhefion of 
furrounding parts, is employed for the capfules of the 
joints. Sixthly, the burke mucofie derive their origin 
front the fame fubftance. The burke are formed in thofe 
parts where a tendon plays over a bone’. The upper fur-- 
face of the burfa is formed by the tendon itfelf; the lower 
furface of the fame burfa is produced from the periofteum. 
of the bone ; and the lides-of the burfa are formed by the 
common cellular fubftance. The burke mucofae and cap- 
fular ligaments do not materially differ in their nature. 
They contain precifely the fame kind of liquor, and they 
frequently communicate with each other. Thus, under a 
variety of modifications, the cellular fubftance is applied 
to many ufeful purpoles in the fyftem. It joins the bones 
to each other, it unites the mufcles to the bones, it gives 
fecurity and fimnefs to their motions by the fluids which 
it contains, it lubricates the joints and mufcular fibre, 
and it is further employed to give a plumpnefs and agree¬ 
able ftiape to the limbs. For all thefe purpoles it appears 
6 T to 
