498 



CARTILAGE. 



sac, and, in some instances, distinctly outside 

 it. Laennec often found them between the 

 tunica vaginalis testis and the tunica albuginea, 

 and on one occasion in the lining membrane 

 of the lateral ventricles of the brain. Andral 

 saw three of these bodies in the serous mem- 

 brane of the brain ; one of them floated loose 

 and unattached in the sac of the arachnoid ; 

 the other two were attached to the choroid 

 plexus by a delicate cellulo-vascular prolonga- 

 tion. He also often found them in the peri- 

 toneum, sometimes perfectly isolated, at other 

 times appended to the serous membrane.* 



2. Accidental cartilages of incrustation, 

 occurring in plates, are very irregular in size 

 and shape. They are most frequently found in 

 fibro-serous membranes, as the dura mater, the 

 pericardium, and the immediate coverings of 

 the testis and spleen. Upon this last viscus 

 they are seen more frequently than in any other 

 situation whatsoever. Bichat supposed they 

 were altered portions of the fibrous membrane, 

 having so generally met with them where the 

 latter existed. The subserous cellular tissue is 

 the proper seat of them. We often find them 

 between the middle and internal coats of ar- 

 teries, in what may likewise be called a sub- 

 serous cellular tissue. (See ARTERY.) 



It is exceedingly rare to meet with them 

 under mucous membranes. Andral saw one 

 solitary instance of a true cartilaginous mass 

 developed in the submucous cellular tissue of 

 the stomach. The subcutaneous cellular sub- 

 stance is likewise nearly exempt from them ; 

 but the same experienced pathologist relates, 

 that one of the lower extremities of a woman 

 who died in La Charite in the year 1820, was 

 affected with elephantiasis ; underneath the 

 skin, and occupying the place of the muscles, 

 which were reduced to a few pale fibres, was 

 found an enormous mass of condensed hard 

 cellular tissue, possessing, in many places, all 

 the physical characters of cartilage. In all 

 these instances there is every reason to believe, 

 from the closest examination, that the newly 

 formed substance is developed at the expense 

 of the cellular tissue alone, and that neither 

 the fibrous nor the serous membranes are al- 

 tered, nor indeed any adjoining texture. These 

 last seem to be replaced by the accidental for- 

 mation, but they are only absorbed to make 

 room for it, and not transformed into the new 

 substance. An exception must, perhaps, be 

 made in favour of mucous membrane, which 

 appears capable of undergoing this change. 

 Laennec relates the case of a child, in the 

 membranous portion of whose urethra he 

 found a large calculus. The mucous mem- 

 brane of the part presented several patches, of 

 the size and thickness of a man's nail, which 

 appeared to him semi-cartilaginous, and were 

 incorporated with, and formed part of, the 

 mucous membrane. In like manner Beclard 

 found the mucous membrane of the vagina, in 

 a case of prolapsus uteri, studded over with 

 cartilaginous spots ; and he observed a similar 



* Andral's Pathological Anatomy, translated by 

 Townsend and West. 



appearance on the prepuce of an old man, who 

 had had phymosis from the time of birth. 



What is the cause of these formations ? 

 Most probably they have their commencement 

 in some obscure inflammatory action. It is 

 true we often find them where there is no other 

 appreciable lesion whatsoever, nor any trace of 

 inflammation in the neighbourhood ; but, on 

 the other hand, they seem to be but a step re- 

 moved, in structure, from coagulable lymph, 

 and are sometimes imbedded in it; and the 

 irritation and consequent inflammation pro- 

 duced by foreign bodies must be allowed to 

 have occasioned them in the instances just 

 related from Bichat and Beclard. 



3. The irregular or amorphous masses 

 which we sometimes see in the thyroid gland, 

 ovaries, uterus, testes, brain, liver, lungs, 

 spleen, kidneys, and heart, are supposed to 

 differ from the preceding classes, not only in 

 form, but in connexions and origin. They 

 appear to be united by continuity of substance 

 with the tissues in which they are developed, 

 and, in fact, to be altered portions of them. But 

 it is by no means proved that cellular tissue 

 may not, even in these cases, be the nidus of 

 such concretions, and that the organs have not 

 rather been absorbed to make room for them, 

 than transformed into them. 



In false articulations, old cicatrices of the liver, 

 lungs, &c., we find a substance resembling car- 

 tilage ; but its description belongs to " Fibro- 

 cartilage" to which we refer. 



Chemical composition. On this subject there 

 is some difference among writers ; Dr. Davy* 

 found diarthrodial cartilage to consist of 



Albumen 44*5 



Water 55-0 



Phosphate of lime 00 5 



100-0 



Berzelius professes his ignorance of its com- 

 position. Neither diarthrodial nor non-articular 

 cartilage yielded gelatine, and he doubts " whe- 

 ther the mass which constitutes them be of a 

 peculiar nature, or similar to what we find in 

 the fibrous coat of arteries." f By boiling 

 costal and synarthrodial cartilages, gelatine is 

 developed. He looks on them to be imperfectly 

 developed bone, and to have the composition of 

 its animal part, with the addition of 3-402 per 

 cent of earth in the false ribs of a man of 

 twenty. 



In 100 parts of this earth he gives the fol- 

 lowing analysis from Frommherz and Gugert ; 

 Carbonate of soda .... 35-068 



Sulphate of soda 24-241 



Muriate of soda 8-231 



Phosphate of soda .... 0*925 



Sulphate of potass 1-200 



Carbonate of lime .... 18-372 

 Phosphate of lime .... 4'056 

 Phosphate of magnesia . 6-908 

 Oxyde of iron, and loss . - 999 



100-000 



* Monro's Elements of Anatomy, vol i. 

 f Traite de Chimie, torn. vii. Par. 1833. 



