ALBUMENOID SUBSTANCES. 



6, Myosine. 



The contractile substance of the striped muscular fibres during life 

 consists largely of a thickish fluid or semifluid alkaline plasma. After 

 death it coagulates, and the coagulating substance, terme<\ "myosine," 

 presents some analogy with the fibrinous matter of the blood. Its 

 spontaneous coagulation gives rise to the condition of cadaveric rigid- 

 ity, in which the muscular fibres lose their power of contraction and 

 relaxation, becoming solidified and opaque. At the same time the 

 reaction of the muscular tissue changes from alkaline to acid. 



The coagulation of the muscular plasma, like that of the blood, is 

 retarded for a time by the action of cold ; and it takes place less 

 rapidly, after death, in the cold-blooded than in the warm-blooded 

 animals. This fact has been used by Ku'hne for its extraction, from 

 the muscular tissue of frogs, in a liquid condition. The vascular 

 system is first deprived of blood by an injection of a one-half per cent, 

 solution of sodium chloride. The muscles, thoroughly washed, are then 

 subjected for two hours to a temperature of t to 10 C. below the 

 freezing-point, reduced to a pulp in a cold mortar, and then allowed 

 gradually to thaw upon a filter. As the temperature rises the filtered 

 fluid coagulates. 



Coagulated myosine is a gelatinous amorphous substance, insoluble 

 in water and in concentrated solutions of sodium chloride ; but is dis- 

 solved by a watery solution of salt, made in the proportion of ten per 

 cent, or less. It may be extracted after death by bruising the muscu- 

 lar tissue to a pulp in a ten per cent, solution of sodium chloride, filter- 

 ing the expressed liquid, and allowing it to fall by drops into a large 

 quantity of distilled water, when the myosine separates by precipita- 

 tion. It is distinguished from coagulated fibrine by its solubility in 

 neutral saline solutions of a certain strength, as well as by its ready 

 solubility in feebly acidulated solutions. When dissolved in a neutral 

 saline fluid it is coagulable by heat, like the albumen of blood. 



7, Syntonine. 



Syntonine is so called because formerly supposed to be the contractile 

 ingredient of muscular flesh, from which it was obtained by extraction 

 with a dilute acid. But a substance having the same characters may 

 be extracted by similar means from many of the animal solids and 

 fluids. Any one of the albuminous matters, if treated with a solution 

 of hydrochloric acid of about 4 parts per thousand, after a time dis- 

 solves and becomes altered in its properties, so that it is soluble in 

 either dilute acids or alkalies, but insoluble in neutral watery liquids 

 and saline solutions. Its solution in a dilute alkali is coagulable by 

 heat, and if previously boiled in water it becomes insoluble in dilute 

 acids. It appears to be identical in character, from whatever source it 

 is derived. 



Obtained by the above means, syntonine is an artificial product. 

 But the same substance is formed in the stomach during digestion by 



