370  Chemistry  of  British  Pharmacopoeia.    {Am^vJ^  Si|rm' 
water  made  isotonic  with  sodium  chloride  and  preserved  by  satura- 
tion with  chloroform. 
Alum  has  had  its  official  title  changed  from  alumen  to  alumen 
purificatum,  but  for  what  reason  is  not  clear,  as  the  requirements 
for  purity  remain  the  same  as  in  the  previous  edition. 
Under  the  Latin  title  Barbitonum  is  described  diethyl-barbituric 
acid,  with  the  synonyms  "  Malonurea  "  and  "  Diethyl-malonyl-urea." 
No  mention  is  made  of  the  proprietary  title  "  Veronal." 
Bensamince  Lactas,  or  benzamine  lactate,  is  the  unfamiliar  name 
for  beta  eucaine.  It  is  defined  as  the  lactate  of  benzoyl-vinyl-diace- 
ton-alkamine,"  a  rather  unusual  designation  for  trimethyl-benzoxy- 
piperidine,  which  is  ordinarily  given  as  the  chemical  name  for  beta 
eucaine. 
The  title  Benzol  has  been  changed  to  Benzenum.  There  is  no 
danger  of  confusion  with  petroleum  benzin,  which  is  recognized 
only  in  the  Appendix  under  the  unmistakable  name  of  petroleum 
spirit,  with  petroleum  ether  as  a  synonym. 
The  title  Borax  has  been  changed  to  borax  purificatus.  The 
reason  is  no  more  apparent  than  for  the  similar  change  referred  to 
under  alum,  for  the  requirements  are  practically  identical  in  both 
books. 
Calcium  Lactate  is  officially  recognized  for  the  first  time  with  a 
rubric  of  93  per  cent,  of  a  salt  containing  5  molecules  of  water  of 
crystallization. 
Cantharidin,  C10H12O4,  is  also  recognized  for  the  first  time.  It 
is  described  as  being  obtained  from  various  species  of  cantharis  or 
of  mylabris,  and  the  melting-point  is  given  as  2100  to  2120  C. 
The  title  of  Carbonis  Bisulphidum  has  been  changed  to  "  Carbon 
disulphidum,"  the  requirements  remaining  essentially  unchanged. 
Chloral  Formamidum  is  the  official  name  of  chloralamide,  recog- 
nized for  the  first  time. 
Cresol  is  recognized  for  the  first  time  and  is  described  as  "  a 
mixture  of  the  isomers  of  the  formula  C7H7OH."  It  is  used  in  pre- 
paring liquor  cresol  saponatus,  also  a  new  addition,  which  consists  of 
50  per  cent,  weight  in  volume  of  cresol  in  a  castor  oil-potash  soap. 
Diamorphince  Hydro chloridum  is  the  rather  unusual  name  selected 
for  the  hydrochloride  of  heroin  or  diacetylmorphine. 
Ethyl  Chloride  is  described  for  the  first  time,  and  in  order  that 
it  may  be  advantageously  made  from  methylated  spirit  it  is  permitted 
to  contain  "  a  small  but  variable  proportion  of  methyl  chloride/' 
