VOL. XC.] PHILOSOPHICAL TRANSACTIONS. 741 



coarse and rigid fibre of adult and aged animals, than in the tender fibre of those 

 which are young ; and this seems to be corroborated by the tendency to morbid 

 ossification, so frequently observed in aged individuals of the human species. 



Gelatin, albumen, and muscular fibre, not only differ very much from each 

 other by the relative quantity of their saline or earthy residua, but also by the 

 proportion of one of their essential and elementary principles, namely carbon. 

 500 gr. of isinglass, made perfectly dry by distillation, yielded 56 gr. of coal, from 

 which, 1.50 gr. of earthy residuum, obtained by incineration, being deducted, the 

 proportion of coal appears to have been 54.50 gr. 500 gr. of dry albumen 

 afforded 74.50 gr.; and as the saline residuum amounted to 11.25 gr., the quantity 

 of mere coal was 63.25 gr. 500 gr. of tortoise-shell yielded 80 gr. of coal; from 

 which 3 gr. of earthy matter being deducted, 77 gr. remain, for the proportion of 

 coal. And 500 gr. of the dry prepared muscular fibre of beef, when distilled, 

 left 108 gr. of coal, which, by incineration, afforded 25.60gr. of earthy residuum; 

 the coal may therefore be estimated at 82.40 gr. There appears much reason 

 therefore to believe, that the gelatinous substances and muscular fibre, differ from 

 simple and unorganized albumen, by a diminution of the carbonic principle in the 

 one, and by an excess of it in the other; and as, in vegetables, the fibrous part is 

 that which contains the largest proportion of carbon, so, in respect to the other 

 animal substances, muscular fibre appears to contain the greatest quantity of it. 



The nature of the residua obtained by the incineration of the substances lately 

 mentioned, also deserves to be noticed. Only 1 .50 gr. was obtained from 500 gr. 

 of isinglass ; and, as far as the quantity would allow, was proved to be phosphate 

 of soda, mixed with a very minute proportion of phosphate of lime. The 3 gr. 

 afforded by tortoise-shell, consisted of phosphate of soda and of lime, with some 

 traces of iron : it is probable that the latter was accidentally present. The pre- 

 pared muscular fibre of beef yielded 25.60 gr. ; the greatest part of which was 

 carbonate of lime, mixed with some pure lime, and a small portion of phosphate ; 

 there can be no doubt but that the latter would have been more abundant, had 

 it not been for the repeated boilings to which the muscular fibre had been sub- 

 jected. The recent muscles of veal and mutton were with great difficulty reduced 

 to ashes ; for, towards the end of the process, the ashes and remaining coal be- 

 came coated and glazed with saline matter, which appeared to be soda, partly in 

 the state of phosphate; and it is not a little remarkable that the 11.25 gr., ob- 

 tained from albumen, consisted chiefly of soda, in a caustic state, by reason of the 

 long continued heat, mixed with a small quantity of phosphate of soda, and 

 a very minute portion of phosphate of lime. Pure albumen therefore, which has 

 not been subjected to the effects of organization, appears to contain a considerable 

 portion of saline matter, and very little of any earthy substance ; but the contrary 

 seems to happen in bodies which, though evidently derived from albumen, have 

 suffered various changes by the action of the vital principle; which may be con- 

 sidered as the cause of organization, by which these bodies are differently modified, 



