352 Dr. W. Marcet on the Nutrition of 



tissue is formed of fibres running parallel with each other in the 

 form of bundles^ which are not in mutual contact^ but separated 

 from those in their immediate vicinity by connective tissue. 

 These fibres consist physically of animal matter and water, 

 held together by a peculiar power which cannot be considered 

 due to a chemical property, but appears to exhibit the character 

 of colloid attraction. The present view rests on the follomng 

 considerations : — 



1st. That muscles have a soft pliable consistence, and are dry 

 to the touch as a jelly would be. 



2nd. That Kiihne, of Heidelberg^ has obtained from muscular 

 tissue a real jelly he has called myosine. 



3rd. That muscular tissue contains a proportion of water 

 which does not appear to vary in health. 



4th. That chloride of sodium, in a certain proportion, inter- 

 feres with the setting of gelatine ; and muscular tissue is nearly 

 free from this substance, while blood (which reoiains liquid) 

 contains it in a comparatively large quantity. And it is worth 

 noticing that when blood loses its chloride of sodium by dialysis 

 (difi'usion) it becomes considerably thickened. 



5th. That after removing by diffusion (dialysis) certain difi'u- 

 sible substances which muscles contain in the small proportion of 

 about 25 per 1000, there remains a mass differing, it is true, from 

 a jelly, inasmuch as it yields a solution of colloid substances by 

 trituration in water, but like a jelly in the fact that the re- 

 moval of these colloid substances leaves a material consisting of 

 substances in a semisolid condition, which are fixed by the water 

 present ; no amount of trituration or pounding or squeezing in 

 water will alter the composition of this soft solid mass, which, if 

 it were not for its tenacity and fibrous consistence, would possess 

 in many respects the characters of a jell}^, holding certain pro- 

 portions of albumen and other equally colloid substances. 



The fact of there being a fixed proportion of water in muscular 

 tissue is remarkable. The consistence of a jelly depends on the 

 amount of water it contains ; a solution of gelatine in too large 

 a bulk of water will not set at all, while the less water this solution 

 contains the more solid the jelly will be. Now it is but fair to 

 assume that muscles must have a certain fixed consistence for the 

 normal performance of their functions ; and if their consistence 

 depends on the proportion of water present, as in the case of a 

 jelly, muscles must contain a fixed proportion of water, which 

 they really do. 



Kiihne has succeeded in extracting from the muscles of frogs 

 immediately after death a substance which sets into a firm 

 coagulum. 



" If a frog be opened, a 1-per-cent. solution of chloride of 



