MUSCLE AND NERVOUS TTSSl'E 



199 



Take equal parts of voluntary muscle, heart muscle, and plain muscle 

 (say from the stomach wall), and extract each for the same time with equal 

 amounts of O15 per-cent. solution of sodium carbonate. Filter and add to 

 each nitrate acetic acid, drop by drop. The extract of voluntary muscle 



Fro. 61. 1, Absorption spectrum of myohaematin, as seen in muscle rendered transparent by 

 glycerin. 2, Absorption spectrum of modified myohaematin. 



gives an opalescence only ; in the case of the plain muscle there is an 

 abundant precipitate ; the heart muscle gives a result intermediate between 

 the other two. 



10. Pigments of Muscle : 



(a] Notice the difference between the red and pale muscles of the rabbit. 



PIG. 62. A desiccator. (Gscheidlen.) a, glass plate ; b, bell -jar ; c, dish of sulphuric acid : 

 d, stand for capsules. 



(b) Examine a piece of red muscle (e.g. the diaphragm) spectroscopically 

 for oxyhaemoglobin (or it may be more convenient to make an aqueous 

 extract of the muscle and examine that). 



((} A piece of the pectoral muscle of a pigeon has been soaked in glycerin. 



