SYNTHETICAL EESEAECHES ON ACIDS OF THE LACTIC SERIES. 



325 



Combinations : — 



Angles. 



10 0, 110 

 010,101 

 1 0, 2 1 

 110, 001 

 110, 201 

 TlO, 001 

 IlO, TOl 

 IlO, 201 



10 0, 010, 001, 110 



10 0, 010, 001,101 



100, 010, 001, 110, 101 



10 0, 010, 001, 110, 110 



100, 010, 001, 110, TOl, 201 



10 0, 010, 01, 110, TOl, IlO 



100, 010, 001, 110, lOl, TlO, 201. 

 Cleavage : — 



10 0, 010, very perfect and easily obtained. 



The optic axes seen in air through the faces of the form 010 appear to make with 

 one another an angle of about 71°. Denoting by a, jS the extremities of radii of the 

 sphere of projection drawn parallel to the directions of the optic axes seen in air 

 through the faces of the form 010, the arcs joining a, p and the nearest poles of faces 

 are approximately as follows : — 



This acid is readily soluble in ether, alcohol, and water ; it is greasy to the touch, and 

 nearly inodorous. It sublimes readily at 50° C, and slowly even at common tempera- 

 tures, a small quantity of the acid left on a watchglass gradually disappearing, though 

 in other respects it is permanent when exposed to the air. It fuses at 74°'5 C Sub- 

 mitted to analysis it gave the following numbers : — 



I. '2732 gvm. gave "5432 grm. carbonic anhydride and -2251 grm. water. 

 II. -3477 grm. gave -6944 grm. carbonic anhydride and -2867 grm. water. 

 MDCCCIAVI. 2 y 



