MUSCLE. 75 



(j.) The chief mineral matter, or salts, consists of potas- 

 sium and phosphoric acid. The watery extract gives a 

 yellow precipitate with platinic chloride, showing the pre- 

 sence of potassium ; while heating it with molybdate of 

 ammonium and nitric acid gives a canary -yellow precipitate, 

 proving the presence of phosphates. 



11. Pea Meal. 



(a.) Make corresponding watery and saline extracts, and 

 perform the same experiments with them as in Lesson XI., 



10, (C.), (d.), (6.), (/.), (0.), (h.) 



(b,) Observe the copious precipitate on boiling the watery 

 extract. 



(c.) Note specially the copious deposit of globulin on 

 adding the saline extract to water. 



12. Bread. 



(a.) Make a watery extract with warm water, filter, and 

 test the nitrate. Its reaction is alkaline. 



(b.) Test for starch and sugar. 



LESSON XII. 



MUSCLE. 

 1. The Reaction. 



(a.) Arrange two strips of glazed litmus-paper, one red 

 and one blue, side by side. Pith a frog; cut out the gastro- 

 cnemius, remove as much blood as possible, divide the 

 muscle transversely, and press the cut ends on the litmus- 

 paper; a faint blue patch is produced on the red paper, 

 showing that the muscle is alkaline during life. The blue 

 paper is not affected. 



(b.) Have some water at 50 C. Dip into it the other 

 gastrocnemius until rigor mortis sets in. Test its reaction ; 

 now it is acid. 





