ITS CHEMICAL RELATIONS. 47 



fectly unmixed condition. In addition to vessels, nerves, fat- 

 cells, and similar structures, the connective tissue constantly 

 exhibits elastic fibres (nuclear fibres], and very frequently also 

 smooth muscular fibres. As these intermixed parts do not admit 

 of being mechanically separated from true connective tissue, such 

 tissues only have been selected for chemical analysis as present 

 the fewest of these morphological elements. On this account the 

 tendons, for instance, have been chosen for analysis. But when so 

 accurate an analyst as J. Scherer* has found that the chemical 

 elements are in the same numerical relations in tendon, notwith- 

 standing this admixture, as in the glutin produced from connective 

 tissue, we cannot wholly reject the assumption that the connective 

 tissue possesses the same elementary composition as glutin. Much 

 weight cannot, however, be attached to conclusions drawn from 

 the best elementary analyses of these substances with high atomic 

 weights ; for even the fact that the tendinous tissue intersected 

 with elastic fibres was found to present the same ultimate compo- 

 sition as the glutin produced only from the fibres of connective 

 tissue in the tendons, sufficiently proves that our analytical methods 

 are not very sensitive in detecting slight admixtures of even very 

 different substances. We should, however, be guilty of rashness, 

 if we regarded it as an established fact, that the connective tissue 

 is isomeric with glutin ; for the constitution of the latter has not 

 been determined with certainty. 



On placing connective tissue in boiling water, it usually at first 

 contracts, but soon swells up, assumes a gelatinous form, and dis- 

 solves after prolonged boiling (the length of time depending upon 

 the density of the tissue, or the minuteness of its previous divi- 

 sion). It contracts also in a slight degree, and thus loses the ten- 

 dency to putrefaction, when treated with bichloride of mercury, 

 alum, basic sulphate of iron, and tannic acid. If the connective 

 tissue is treated for a prolonged time with dilute acids or alkalies 

 at the boiling point, it is found to be much more rapidly metamor- 

 phosed into glutin than when it is boiled in mere water. 



The connective tissue swells in concentrated acetic acid and be- 

 comes transparent, or at all events this is the case with the tendons, 

 ligaments, &c., which are chiefly formed of this tissue ; but this 

 gelatinous mass is only thoroughly dissolved on the addition of water 

 and the application of heat, and neither red nor yellow prussiate of 

 potash produces any precipitate from this acetic-acid solution. The 

 true fibres of the connective tissue are found by micro-chemical iri- 

 * Ann. d. Ch. u. Pharm. Bd. 40, S. 1-45. 



