352 
Forms Observed: q = {011}, large and very lustrous; a = {100}, 
large, mostly with one rudimentary face, but yielding good reflexes ; 
b= {010}, narrower, sometimes curved; r= {101}, great and lustrous ; 
m == {110}, perfectly reflecting; w= {111}, mostly narrow, but in 
the needle-shaped individuals as large as am, while 7 is here lacking 
in most cases; finally 0 = {311}, often well developed. The aspect 
of the erystals is thick prismatic, with a slight elongation parallel 
to the a-axis; rarely needles parallel to the same axis. 
Angular values: Observed: Calculated: 
q:q= (011): (O11) =* 67959! 2e 
g: a= (011): (100);—* 780-9 == 
a:m=(100): (110) =* 52 14% — 
g:6b6=(011):(010)= 56°0 56210 
a:r= (100):(101)= 53 14 53.21 
ger == (OL) S00 sal 14 41 9 
b:m= (010): (110) = 37 44 37 45! 
a:w=(100):(111)= 74 49 Tyee 
wee MD Ollie 25.08 24 49 
a:o=(100):(311)= 40 50 40 58 
ong = (311)... 5e 1 58 53 
No distinct cleavage was found. 
The extinetion-angle on {010} is 31° with respect to the a-axis. 
The specific weight of the crystals is: 1,454 at room-temperature; 
the equivalent-volume is thus: 165,06, and the topical axes are 
calculated at: x: W:w = 7,5309 : 5,7009 : 3,9291. 
§ 7. V. p-Toluene-sulpho-ethylamide. 
This compound, which melts at 64° C., has the structure: 
CH, 
2 
SO,NH(C3H5) 
It crystallizes from a mixture of absolute alcohol and ether in 
colourless, parallelogram-shaped, thin plates, or small prismatic crystals. 
The solutions have a tendency to supersaturation. 
Triclinic-pedial 
a:6:c=0,6481 : 1: 0,4136; 
oa 173 A= TS 
BOS 2 BS VSB 
y = 102°55}3; CG = 102 
