176 
Mile  feding, 
J  Am.  Jour.  Pharm. 
I    April  1,  1873. 
may  be  held  to  be  only  relative,  the  precise  quantity  of  any  oil 
"  emulsifiable"  by  a  given  quantity  of  mucilage  depending  directly 
upon  the  degree  of  viscosity  of  the  latter.  If  it  be  desired  to  combine 
an  oil  in  much  larger  proportion  than  appears  in  the  formula  given, 
this  may  be  effected  to  an  almost  incredible  extent  by  substituting 
brisk  stirring  in  a  mortar  during  the  adding  of  an  oil,  for  the  mere 
agitation  that  sufficed  in  the  former  case.  It  is  probable  that  a  great 
variety  of  substances  upon  which  I  have  not  yet  experimented  may 
be  treated  advantageously  as  above. 
My  experience  has  been  mainly  with  the  oils  of  castor,  cod-liver, 
olive  and  turpentine,  and  the  success  attending  the  use  of  these  was 
perfect,  none  of  them  showing  any  disposition  to  separate  after  many 
months  keeping,  and  retaining  then  a  degree  of  sweetness  and  fresh- 
ness that  proved  keeping  qualities  of  a  very  perfect  order. — Pharm. 
Journ.  and  Trans.,  March  8,  1873. 
MILK  TESTING. 
By  Thomas  Garside. 
I  wish  to  point  out  a  fact,  in  connection  with  the  estimation  of  cream 
in  milk  by  means  of.  the  lactometer,  which  I  have  not  hitherto  seen 
noticed,  namely,  the  great  difference  in  the  results  which  a  slight 
variation  in  the  temperature  produces.  In  Dr.  Hassall's  article  on 
the  estimation  of  the  cream,  given  in  his  work  "Adulteration  Detected," 
I  do  not  observe  that  any  account  is  taken  of  this  ;  the  only  reference 
to  temperature  which  I  find  being  in  the  following  terms  : — "  Cream 
forms  more  quickly  in  warm  than  cold  weather  ;  and  in  making  com- 
parative observations  on  a  number  of  samples,  it  is  proper  that  each 
should  be  set  aside  in  lactometers  at  the  same  time  and  for  the  same 
period''  (p.  225).  Provided  that  the  lactometers  were  all  maintained 
at  the  same  temperature,  this  method  would  give  accurate  results  for 
the  samples  operated  upon  ;  but,  as  the  following  experiments  will 
show,  no  dependence  could  be  placed  upon  them  unless  the  latter  con- 
dition were  complied  with,  nor  could  any  set  of  observations  be  of 
use  for  comparison  with  another  set  unless  the  temperature  were  main- 
tained at  the  same  point. 
In  each  of  the  following  cases  two  graduated  tubes  were  filled  with 
milk  from  the  same  pail,  as  supplied  in  the  usual  way  by  the  dealer, 
and  a  uniform  temperature  was  maintained  during  the  time  mentioned. 
