348 
ON  MYCOSE,  THE  SUGAR  OF  ERGOT  OF  RYE. 
already  called  attention  to  this  fact  on  several  occasions,  and 
indeed  first  with  regard  to  the  acid  phosphate  and  arseniate  of 
potash,  which  are  obtained  with  smooth  faces  from  a  solution 
containing  a  little  neutral  salt ;  with  a  slight  excess  of  acid,  the 
inclination  of  the  secondary  plans  towards  one  another  becomes 
more  obtuse,  by  as  much  as  1°,  and  with  a  greater  excess  the 
faces  become  so  curved  that  they  are  no  longer  measurable. 
The  form  of  the  crystals  is  a  regular  octahedron.  When  ex- 
posed for  a  long  time  to  a  temperature  of  212°  F.,  in  a  water- 
bath,  the  sugar  fuses  into  a  perfectly  transparent  fluid,  which 
becomes  glassy  on  cooling,  and  only  grows  crystalline  after  a 
considerable  time  ;  at  the  same  time  it  gives  off  but  little  water, 
which  was  undoubtedly  only  enclosed  mechanically.  Heated  to 
266°  F.,  in  the  zinc-bath,  it  gives  off  much  water,  and  becomes 
inflated  ;  at  last  it  again  becomes  solid,  and  even  when  strongly 
heated  gives  off  no  more  water ;  at  410°  F.,  the  hard,  vesicular 
mass  fuses,  becomes  brown  when  a  little  more  strongly  heated, 
and  at  the  same  time  evolves  an  odor  of  caramel.  Sugar  that 
lias  been  heated  to  this  temperature  dissolves  in  water  with  a 
brown  color,  and  its  solutions,  evaporated  in  the  air,  furnishes 
crystals  of  unaltered  sugar,  with  which  some  uncrystallizable 
sugar  is  mixed.  When  exposed  to  a  higher  temperature,  it  is 
completely  decomposed;  a  spongy  coal  remains,  which  burns 
without  residue  in  the  air.  At  212°  F.,  it  loses  9-62  per  cent. 
The  analysis  gave,— - 
C  38-37  12  38-09 
H  6-87  11  6-88 
0      54-76      11  55-02 
Of  water  of  crystallization  it  would  contain  2  atoms  =9-52 
per  cent,  so  that  the  sugar  would  consist  of  C12  H11  Ou+2HO. 
0.7485  grms.  of  the  sugar  was  dissolved  in  a  little  water,  the 
solution  poured  into  a  glass  bottle,  which  displaced  7-463  grms. 
of  water,  and  the  bottle  was  filled  with  water.  The  fluid  weighed 
7*7310  grms.  so  that  it  had  a  spec,  grav.  of  1*036 ;  this  solu- 
tion therefore  contained  9.68  per  cent,  or  10-03  grms.  of  sugar 
in  100  cub.  centims.  When  put  into  a  tube  200  millims.  in 
length,  this  solution  rotated  the  plane  of  polarization  by  34f  ° 
to  the  right;  the  same  quantity  of  cane-sugar  effects  a  rotation 
