480  Chemical  and  Pharmacognostical  Notes.  {^'stlTuM1^' 
obtained,  which  bear  the  constant  relation  of  1  :  3*7,  as  determined  in 
about  twenty  samples  of  yellow  wax.  About  4  grams  wax  is  treated 
with  20  cc.  neutral  95  per  cent,  alcohol,  heated  to  fusion,  and  titrated 
with  alcoholic  potash  solution,  phenolphthalei'n  being  used  as  indicator. 
When  the  first  number  has  been  obtained,  20  cc.  potash  solution  are 
added,  and  the  excess  titrated  with  half  normal  hydrochloric  acid. 
For  the  acid  in  1  gram  wax  about  19  to  21  mgrm.  KHO  are  required, 
and  for  the  saponification  73  to  76  more  are  required.  The  proportion 
varies  between  1  ;  3*6  and  1  :  3*8,  and  the  total  potassium  hydroxide 
used  is  92  to  97  mgrm.  The  author  designates  the  numbers  thus 
obtained  as  acid  number,  ether  number,  and  saponifying  number, 
respectively.  Wax  substitutes  give  very  different  values  for  these 
numbers,  as  the  following  average  results  show  : 
Substance. 
Acid 
Ether 
Saponifying 
Proportion 
number. 
number. 
number. 
ether:  acid 
20 
200 
220 
.  10 
4 
75 
* 
19  . 
Tallow   
4 
176 
180 
44 
195 
0 
195 
0  :  195 
110 
1*6 
112 
0*015 
0 
0 
0 
0 
20 
75 
95 
3-75 
Hence  if  the  saponifying  number  falls  below  92  with  a  proper  pro- 
portion, the  wax  is  adulterated  with  an  inert  substance  (i.  e.,  paraffin). 
If  the  proportion  be  greater  than  3*8,  an  addition  of  Japan  or  carnauba 
wax  or  tallow  is  probable.  If  the  acid  number  be  low,  Japan  wax  is 
excluded,  and  of  the  remaining  two  the  ether  number  will  determine 
which  has  been  used.  If  the  proportion  be  below  3*6,  stearic  acid  or 
resin  has  probably  been  added.  It  is  also  clear  that  the  simultaneous 
presence  of  an  active  and  an  inactive  substance  may  be  detected  by  the 
figures  obtained.    The  subject  is  being  further  investigated. — Ibid. 
Gelatin.— H.  Weiske  ("Bied.  Centr."  1883,  p.  673)  has  prepared 
gelatin  in  various  ways,  and  has  found  that  the  products  differ  in  pro- 
perties. Pieces  of  bone  were  treated  repeatedly  and  for  a  long  time 
with  dilute  hydrochloric  acid  to  remove  the  inorganic  matter  as  com- 
