44 CARTILAGE. 



the microscope to the action of a solution of potash, sulphuric 

 acid and water ; the granular or slightly fibrous intercellular sub- 

 stance first disappeared, next the margin or investing membrane 

 of the original parent-cells (which also disappears after prolonged 

 exposure to the action of acetic acid), then the membranes of the 

 cells, and finally their nuclei. If from this it would seem a probable 

 conclusion that the cell-walls and the nuclei did not essentially 

 differ in their chemical constituents from the intercellular sub- 

 stance, the more especially as by continuous boiling with water 

 the cells appear to be expelled and converted into chondrin, yet 

 Mulder and Donders were led, from the relations of elastic fibro- 

 cartilage, to the view that the morphological elements of cartilage 

 closely resemble, in a chemical point of view, the intercellular 

 substance, and that the observed differences are only dependent 

 on a varying degree of cohesion of the deposited materials. The 

 elastic fibro- cartilages, for instance, yield chondrin on boiling, 

 while, with the exception of the cartilage-cells, they appear to 

 contain no chondrin-yielding substance : while, on the other hand, 

 the semilunar cartilages of the knee, notwithstanding their con- 

 taining an abundance of cartilage-cells, yield only glutin, and not 

 a trace of chondrin. It was this last-named circumstance that 

 induced Hoppe* to take up the rigid investigation of fibro- 

 cartilage and its relations, and he came to the conclusion that the 

 cartilage-corpuscles are imbedded in a chondrin-yielding substance 

 within the elastic tissue. He found, namely, that after elastic 

 fibre -cartilage had been boiled for three hours, a certain amount of 

 chondrin was formed, but that the cartilage-cells (for the most part 

 perfectly unaffected) might be observed in the fluid as well as in the 

 residual, strongly contracted elastic tissue. (The compressor was 

 requisite to see them in the latter.) Hence Hoppe concluded that 

 cartilage- cells cannot consist of gelatigenous substance, and was led 

 to the axiom that cell-membranes and cell-contents never consist 

 of such a substance, and further, that a cell-membrane can never be 

 metamorphosed into gelatigenous tissue. Donders has, moreover, 

 essentially modified his former view regarding the chemical consti- 

 tution of the walls of the cartilage-cells, and both these experi- 

 mentalists may be regarded as perfectly coinciding in these general 

 statements and results. (See " Elastic Tissue. 5 ') 



Mulder first proved that chondrin contains a small quantity of 

 sulphur ; but the amount of this substance in the tissue of true 

 cartilage, and whether the sulphur exists in all, or only in some of 

 * Arch. f. pathol. Anat. Bd. 5, S. 170-188. 



