Am.  Jour.  Pharm. )     State  Pharmaceutical  Associations. 
Noyember,  1909.  J 
541 
parts  of  ether,  and  in  3800  parts  of  chloroform  at  25 0  C.  (770  F.) 
is  a  mass  of  information  that  for  practical  purposes  is  difficult  to 
remember  and  if  remembered  difficult  to  apply;  and  suggests  that 
for  all  practical  purposes  the  use  of  certain  expressions,  if  properly 
defined,  would  be  sufficient.  For  all  ordinary  purposes  he  advises 
the  inclusion  of  the  following  definitions  in  the  Pharmacopoeia. 
Articles  that  are  soluble  in  less  than 
1  part  of 
1-10  parts  of 
10-100  parts  of 
100-1000  parts  of 
1000-10,000  parts  of 
10,000-100,000  parts  of 
More  than  100,000  parts  of 
solvent  =  very  soluble, 
solvent  =  freely  soluble, 
solvent  =  soluble, 
solvent  =  slightly  soluble, 
solvent  =  very  slightly  soluble, 
solvent  =  nearly  insoluble, 
solvent  =  practically  insoluble. 
The  same  definition  is  stated  in  another  form  as  follows : 
100  c.c.  of  solvent  will  dissolve : 
100  Gm.  or  more  of  a  "  very  soluble  "  substance. 
10  to  100  Gm.  of  a  "  freely  soluble  "  substance. 
1  to     10  Gm.  of  a  "  soluble  "  substance. 
0.1  to      1  Gm.  of  a  "  slightly  soluble  "  substance. 
0.0 1  to  0.10  Gm.  of  a  "  very  slightly  soluble  "  substance. 
0.001  to  0.0 1  Gm.  of  a  "  nearly  insoluble  "  substance. 
Less  than  0.001  Gm.  of  a  "  practically  insoluble  "  substance. 
Exact  information,  the  writer  states,  regarding  solubilities  could 
be  tabulated  in  the  appendix,  as  is  done  in  the  Belgian  Pharma- 
copoeia. This  would  be  an  incentive  for  concerted  effort  to  correct 
and  correlate  data  regarding  solubilities.  As  an  illustration  of  the 
need  for  such  work  he  gives  the  solubility  of  acetanilid  in  cold 
water  and  cold  alcohol,  as  published  in  twelve  well-known  books. 
Solubility  of  acetanilid  as  given  in  these  books,  usually  without 
temperature  qualifications : 
Ph.  Germ. 
Ph.  Belg. 
Ph.  Bri.  Ph  Helv.  Ph  Dan. 
U.  S.  P.   B.  P.  C.  Ph.  Hisp.  Ph.  Md.  Cordex.  Ph.  Svec  Ph.  Austr. 
Sol.  in  water   179       190      200      210      220      230  250 
Sol.  in  alcohol....     2.5         4       3.5       3.6       3.5       3.5  3.5 
Pa.  Pharm.  Assoc. 
