Muscular and Pulmonary Tissues. 355 



with the material destined to its nutrition, to which the albumen 

 belonged. It might be objected that a small quantity of blood 

 was possibly left in the tissue after slaughtering, which would 

 account for the presence of albumen in the water in which the meat 

 was steeped ; but meat from slaughtered animals is perfectly free 

 from blood. On triturating minced ox-flesh with salt water I 

 could not find any blood-corpuscles by subjecting various por- 

 tions of the mass to microscopical examination, while on adding 

 one or two drops of serum containing some blood-corpuscles to 

 a few ounces of the pulpy mass, and agitating the whole 

 together, the blood-corpuscles could be detected most readily. 

 In the tissue of the heart of the ox, however, I usually found 

 small quantities of blood, and had to give up determining the 

 albumen in extracts of that organ because of the results being 

 too high on that account. On these occasions I had no diffi- 

 culty in detecting the presence of blood. 



Keturning to my subject, I hope to have succeeded in showing 

 that muscular tissue consists of a solid material permeated by 

 channels containing an albuminous fluid, and that the consti- 

 tuents of the solid material are bound together by a force similar 

 to that which connects gelatine and water in a jelly. 



On the Mode of Nutrition of Tissues. 



A tissue consists of a solid portion containing a fluid nutritive 

 material within its mass. It must appear obvious at the outset 

 that if the solid portion is colloid, the material for its for- 

 mation must also be colloid ; indeed it is well known that albu- 

 men, a thoroughly colloid substance, takes a considerable share 

 in the process of nutrition. I shall show that the phosphoric 

 acid, together with the small quantity of potash (and, we may 

 assume, also the magnesia), which enter into the composition of 

 the nutritive material are also colloid ; muscular tissue contains, 

 however, nearly 25 per 1000 of crystalloid material, consisting of 

 potash and magnesia salts, and very small proportions of chlo- 

 rine and soda, together with crystalloid organic nitrogenized sub- 

 stances, such as kreatine and kreatinine. It occurred to me that 

 the formation of these crystalloid substances was due to the pro- 

 cess of w^aste — a view which derived some support (before it was 

 thoroughly investigated) from the fact that the urinary secretion 

 consists of difi'usible substances ; the transformation of colloids 

 into difi'usible crystalloids appeared moreover at the outset a 

 convenient method for a process of elimination ; and also, blood 

 being much more colloid than tissues, could hardly be considered 

 the source of the crystalloid substances they contain. 



The nitrogenized crystalloids in tissues would result entirely, 

 according to this view, from a transformation of assimilated albu- 



2 A2 



