Muscular and Pulmonary Tissues, 353 



sodium driven through the blood-vessels until all the blood is 

 removed, the muscles then rapidly chopped up and subjected to 

 firm pressure, a liquid will be obtained which in a short time 

 sets into a firm coagulum." — Myologische Untersuchungen (ex- 

 tracted from Watts^s Dictionary of Chemistry). 



Therefore juice of flesh has a tendency to coagulation, as would 

 a solution of gelatine ; this tendency must be possessed by those 

 substances in juice of flesh which are soluble and colloid, and 

 therefore, as I shall show, destined to the nutrition of flesh, or 

 to become transformed into muscular tissue. 



I conclude that there is a strong ground for the belief that 

 the elementary physical constitution of muscle is that of a jelly — 

 with this difference, that it is organized so as to possess due 

 tenacity for the performance of its functions ; but the water, al- 

 bumen, and other constituents hold apparently the same rela- 

 tion to each other as water would to gelatine in a jelly*. 



Bone may be considered as consisting criginally of a jelly of 

 a colloid material and water, the water being subsequently re- 

 placed by phosphate and carbonate of lime and magnesia, which 

 are united with the colloid material much in the same way as 

 the water had been originally united to this same material. 

 The existence of a colloid constituent of bone very much resem- 

 bling gelatine is easily demonstrated by the well-known expe- 

 riment of immersing a bone in dilute hydrochloric acid, when the 

 earthy matters are removed, water taking their place and entering 

 into a colloid union with the gelatinous matrix, the union being 

 apparently similar to that which had existed before between the 

 earthy matters and the colloid material. The connexion between 

 water and gelatine in a jelly obviously takes place between two 

 colloid bodies, although water may under certain circumstances, 

 as under the influence of cold, assume the crystalloid condition ; 

 and moreover we find that, in the formation of bone, phosphate 

 and carbonate of lime and magnesia exist in an amorphous or 

 non-crystalline state; I therefore consider these earthy sub- 

 stances as existing in a colloid condition in osseous tissue. 



Animal tissues, although in some respects resembling a jelly, 

 vary, of course, essentially from this colloid material because of 

 their having a definite structure. Virchow has discovered with 

 the microscope that there exists in muscular and other tissues 

 a complex system of minute channels, the object of which is ap- 

 parently to allow of the transmission of the nutritive material 

 to the different parts of the tissues. Indeed it is very difficult, 

 not to say impossible, to account for the distribution of the col- 

 loid material destined to nourish tissues after it has left the blood, 



* Nerves and vessels form such a very minute proportion of muscle that 

 I have overlooked them in the present inquiry. 



Phil. Mag, S. 4. Vol. 44. No. 294. Nov, 1872. 2 A 



