XIV.] MUSCLE. 99 



CuS0 4 . This is best seen on slightly heating. Take care not to 

 boil the liquid, or the reaction for sugar will be got instead. 



(//.) Extract some wheaten flour with a 10 per cent, solution of 

 common salt for twelve hours. Filter, and drop some of the clear 

 filtrate into a large vessel of water ; a milky precipitate of a 

 globulin is obtained. 



(/?.) On saturating some of the filtered saline extract (g.) with 

 powdered NaCl or MgS0 4 , a precipitate of a globulin is thrown 

 down. 



('.) Fats. Shake up some wheaten flour with ether in a cylindrical stop- 

 pered vessel or test-tube, with a tight fitting cork. Allow the mixture to 

 stand for an hour shaking it from time to time. Filter off the ether ; place 

 some of it on a perfectly clean watch-glass, and allow it to evaporate spon- 

 taneously, when a greasy stain will be left. 



(,/.) The chief salt is potassium phosphate. The watery extract 

 gives a yellow precipitate with platinic chloride, showing the 

 presence of potassium ; while heating it with molybdate of am- 

 monium and nitric acid gives a canary-yellow precipitate, proving 

 the presence of phosphates. 



12. Pea-Meal. 



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

 the same experiments with them as in Lesson XIII. 11, (c.), (d.), 



M, (A (.?)> W- 



(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. " 



13. Bread. 



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

 filtrate. Its reaction is alkaline. 



(b.) Test for starch and sugar. 



(c.) The insoluble residue gives the xanthoproteic and othei 

 proteid reactions. 



LESSON XIV. 



MUSCLE. 

 1. Reaction. 



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

 blue, side by side. Pith a frog ; cut out the gastrocnemius, remove 

 as much blood a ^ossibte, divide the njusftle transversely, and 

 press the cut ends on the litmus-paper : a faint blue patch is pro- 



