345 
of the c-axis the angular values are mostly oscillating, the reflexes 
being multiple; with very thin individuals, however, exact measure- 
ments could be made. The aspect of the crystals is that of prisms 
elongated in the direction of the c-axis. No distinct cleavage was 
found. The prism-faces (110) and (110) were much more lustrous 
and yielded much sharper images than the faces (110) and (110), 
which ordinarily were somewhat curved and duller. 
Angular Values: Observed: Calculated: 
):(110) =* 44 18 = 
ya(101)=*) 37 12 = 
):(010) = 45 44 45°42’ 
):(110)= 91 28 91 24 
LON 1124 71 24 
PO Vine 10 76 1845 
(Op = Te 76 18}/s 
The crystals are positively birefringent. 
The optical axial plane is {001}; on the 
prism-faces, just at the border of the field, 
the emergence of an optical axis is obser- 
vable. The dispersion bas a rhombic charac- 
ter, with 9 >v. The aspect of the crystals 
is very much like that of the B-derivative. 
§ 4. p-Chloro-tetracetyl-d-fructose 
(mpt.: 108° C.) erystallizes from benzene 
U 
' 
' 
' 
‘ 
' 
‘ 
| 
1 
' 
1 
' 
| 
- “~ 
in the shape of large, clear, very lustrous 
and short prismatic crystals, which with 
exception of their smaller development in 
the direction of the c-axis, show an un- 
Fig 2 (-Chloro-tetracetyl- 5 ; 
: Et Nh deniable analogy with the erystals of the 
a-compound. 
Big, colourless crystals, yielding, however, ordinarily multiple 
. reflections, and imperfectly built. 
Rhombic-bisphenoïdical. 
20762157478: 1 OM EL2: 
Forms observed: a =—={100} and m=={110}, well developed and 
giving sharp images; r == {101}, large, eminently reflecting; once a 
positive bisphenoid, probably {523}. and very subordinate, was 
observed, difficultly measurable. 
