CHAP. IX.] THE CONTRACTILE TISSUES. 337 



Perparation An aqueous extract of muscle (preferably of the 



from Muscle. muscular tissue of the heart) is prepared. This is freed 

 joedecter's f rom a ik umm by "boiling &c., then treated with baryta 

 water to free it from phosphates; it is concentrated, set 

 aside, and the creatine is allowed to crystallize out; the mother liquor 

 is boiled with four times its volume of alcohol; a precipitate is formed 

 which, according as it adheres to the bottom or separates in a floccu- 

 lent form, is separated by decantation or nitration. The clear liquid 

 is set aside for 24 hours, when crystals of inosit often separate ; if not, 

 ether is added and the mixture of alcohol and ether shaken again 

 and again ; inosit then separates out gradually in the form of leaflets 

 having the lustre of mother-of-pearl. An excess of ether does not 

 interfere with the precipitation, but merely causes the separating 

 crystals to be smaller (Hoppe-Seyler). The impure inosit obtained 

 by the above methods is collected on a filter, washed with cold 

 alcohol, and recrystallized from water. 



Pr parties Inosit crystallizes in the form, of large, colourless, 



roonoclinic tables, sometimes arranged in groups like 

 cauliflower-heads. 



The crystals of inosit have a specific gravity of 1*1154 at 5 ; they 

 effloresce in dry air, or in vacuo ; at 100 C. the whole of the water of 



FIG. 56. INOSIT FROM THE MUSCULAR SUBSTANCE OF THE HEART OF MAN. (FREY.) 



crystallization is given off, and the anhydrous inosit melts at 110, 

 setting, on sudden cooling, in fine needles. Inosit dissolves in 6 parts 

 of water at 19 0. ; it is insoluble in absolute alcohol and ether. 

 Solutions of inosit when boiled with basic lead acetate yield instantly 

 a transparent jelly (containing the compound C 6 H 12 6 2Pb 2 0) ; this 

 reagent has been, indeed, employed by some observers in the separation 

 of inosit. 



Inosit has a sweet, saccharine, taste ; it is not fermentable ; it 

 does not rotate the plane of polarization ; it does not yield a yellow or 



1 Boedecker, Ann. d. Chem. u. Pharm., Vol. cxvu. p. 118. 

 G. 22 



