ABQ'jifiy''i9Sfrm'}    Recent  Literature  Relating  to  Pharmacy.  357 
severely  damages  within  twenty-four  hours;  O-i  per  cent,  thymol 
destroys  its  fermentative  power. 
A.  — Yeast  invertase  (invertin). 
B.  — With  700  C.  moist  heat  it  is  rapidly  destroyed ;  at  500  a 
longer  time  is  required.  It  works  best,  according  to  A.  Mayer,  at 
3 1 0  C. ;  according  to  Kjeldahl,  at  from  5  2°-56°  C.  (These  statements 
certainly  have  reference  to  different  invertases.) 
C.  — In  entirely  dried  yeast  there  is  still  active  invertin  present. 
O'Sullivan  and  Thompson  have  prepared  it  from  powdered  beer 
yeast. 
D.  — The  purer  the  invertase  the  more  it  is  injured  by  alcohol 
(O'Sullivan  and  Thompson).  And  it  is  said  to  be  easily  dissolved 
out  of  the  yeast  by  means  of  water.  The  invertase  in  cane-sugar 
solution  can  be  heated  25 0  C.  higher  than  the  temperature  at  which 
it  was  destroyed  in  pure  water  (O'Sullivan  and  Thompson). 
E.  — The  ammonia  salts,  even  in  higher  concentration,  accelerated 
the  production.  Very  small  additions  of  sulphuric  acid  act  favor- 
ably (0  001  to  002  per  cent.,  according  to  O'Sullivan  and  Thomp- 
son). 
F.  — 01  per  cent,  mercuric  chloride  does  not  entirely  impede  the 
inversion  of  cane  sugar,  but  0-5  per  cent,  prevents  it  in  two  days, 
0-02  per  cent,  silver  nitrate  does  not  impede  it,  but  01  percent, 
prevents  it  entirely.  5  per  cent,  of  formaldehyde  does  not  destroy 
in  t\>\enty-four  hours. 
G.  —  I  per  cent,  sodium  hydrate  destroys  the  fermentative  power 
in  twenty-four  hours;  0  5  per  cent,  does  not  destroy  it  even  within 
four  days.  0.5  per  cent,  sulphuric  acid  damages,  but  does  not 
entirely  destroy  the  fermentative  power  within  twenty-four  hours, 
hydrochloric  acid  acting  the  same.  1  per  cent,  oxalic  acid  does  not 
perceptibly  damage  within  twenty-four  hours. 
H.  —  1  per  cent,  carbolic  acid  does  not  damage  within  twenty-four 
hours;  the  same  with  o-i  per  cent,  thymol.  Borax  damages.  Even 
absolute  alcohol  does  not  destroy  by  an  action  of  twenty  days. 
W.  S.  Weakley. 
THE   VALUATION   OF  CORTEX  GRANATI. 
Stoeder  (Pharm,  Weekblad.,  1902,  21)  gives  the  following  method 
for  the  valuation  of  this  bark  :  Twenty  grammes  of  the  dry  pow- 
dered bark  are  shaken  well  with  100  c.c.  of  chloroform  and  5  c.c. 
