and Observations on the component Parts of Membrane. 393 



to a pulpy mass.* I am inclined therefore to suspect, that strong 

 and completely formed muscular fibre, considered as a distinct 

 substance, is not of easy putrescibility ; and that the readiness 

 with which muscle in general enters into putrefaction, is prin- 

 cipally owing to the gelatin, which is combined and mixed with 

 it, in a large proportion, as a component part, and which, with 

 the natural quantity of moisture, is requisite to give the fibre a 

 proper degree of toughness and flexibility. 



The residuum afforded by muscular fibre which had been 

 long steeped in dilute nitric acid, and afterwards immersed in 

 ammoniac, consisted principally of fat, mixed with a small por- 

 tion of the fibre which had not been sufficiently acted upon by 

 the acid ; and little or no earthy matter was thus obtained. 



But, when the prepared muscular fibre was dissolved in boil- 

 ing nitric acid, a complete solution, resembling that of albumen, 

 in its general properties, was formed ; and some fat floated, in 

 drops, at the top of the liquor. 



Ammoniac was then added, so as to super-saturate the 

 acid, and produced the same effects as on the nitric solutions 

 of albumen, excepting, that a copious white precipitate was 

 obtained. 



This precipitate, while moist, was agitated with a quantity of 

 acetous acid, which dissolved, and separated, a small portion 

 of phosphate of lime; but the remainder, and by much the 

 greatest part of this precipitate, was scarcely attacked, even 



when the acid was boiled. 



1 



When exposed to a red heat, it became dark gray, and then 



* A portion of this muscular fibre was kept under water during two months ; it 

 did not however become putrid, nor was it converted into that fatty substance which 

 is obtained from recent muscle, under similar circumstances. 



3E 2 



