246  Minutes  of  the  Pharmaceutical  Meeting.  {Arn^yv;^Tm^ 
used  for  nitrogen  estimation,  another  is  precipitated  by  barium 
chloride,  to  ascertain  the  amount  of  adhering  ammonium  sulphate. 
(The  relation  of  the  ammonia  to  the  sulphuric  acid  in  the  solution 
used  should  be  determined,  not  calculated.)  The  corrected  nitrogen 
in  the  precipitate  gives  the  amount  of  albumose  and  gelatin. 
The  peptone  is  known  by  difference,  its  actual  presence  being 
confirmed  by  concentrating  the  remainder  of  the  solution,  preci- 
pitating the  albumose  and  gelatin  by  solid  ammonium  sulphate, 
and  testing  the  filtrate  by  adding  a  trace  of  cupric  sulphate  and  a 
large  excess  of  strong  soda  solution.  Peptone  gives  a  characteristic 
red  color. 
The  gelatin  is  best  estimated  by  means  of  the  viscosimeter,  the 
viscosity  being  compared  with  that  of  a  standard  solution  of  the 
best  white  gelatin,  to  which  an  equal  volume  of  a  20  per  cent,  solu- 
tion of  serum  peptone,  free  from  gelatin,  has  been  added.  A  10  per 
cent,  solution  of  the  substance  is  prepared  and  cooled  for  three 
hours  to  a  temperature  lower  than  that  at  which  the  comparison  is 
to  be  made.  It  is  then  gradually  warmed  to  a  standard  temperature, 
and  immediately  examined  for  viscosity.  Very  dilute  solutions  may 
be  compared  at  o-i°,  whilst  strong  ones  may  need  to  be  warmed 
to  25 °,  but  it  is  not  permissible  to  warm  above  the  standard 
temperature,  and  again  cool  just  before  testing.  Calling  the 
viscosity  of  a  10  per  cent,  solution  of  serum  peptone  100,  the  addi- 
tion of  0-25  per  cent,  of  gelatin  raises  it  to  130  at  o-i°,  114  at  150, 
106  at  200. 
Having  now  ascertained  the  amount  of  nitrogen  in  the  alcohol 
precipitate  in  the  form  of  albumose  ,  peptone  and  gelatin,  the  remain- 
ing nitrogen  is  to  be  regarded  as  belonging  to  the  flesh  bases. 
The  principal  of  these  is  creatin,  with  32-8  per  cent,  of  nitrogen, 
whence  the  multiplication  of  the  nitrogen  by  the  factor  3-12,  gives 
the  total  amount  of  the  bases  with  but  small  error. 
MINUTES  OF  THE  PHARMACEUTICAL  MEETING. 
Aprix  25,  1893. 
On  motion  of  Prof.  Remington,  Mr.  Mclntyre  was  called  to  preside.  The 
minutes  of  the  last  meeting  were  read,  and  no  corrections  being  required,  they 
were  approved. 
Professor  Trimble  presented  two  quarto  volumes  of  Macquer's  Dictionary  of 
Chemistry,  1778.    It  is  interesting  as  a  history  of  the  science  at  that  time. 
