AmAjrii,r'i9?9.rm'  ^       ^  Pharmaceutical  Chemist.  223 
so-called  "  dead  oils "  as  a  basis  for  disinfectants  of  considerable 
potency;  pure  cresylic  acids,  to  make  antiseptics  for  surgical  or 
general  use ;  and  phenol  for  use  as  such  or  in  various  compounds 
such  as  phenyl  salicylate  (salol)  or  the  phenolsulphonates  of  zinc 
and  calcium. 
The  dye  chemist  furnishes  for  medicinal  use  such  things  as  phe- 
nolphthalein,  so  widely  employed  as  a  laxative ;  phenolsulphonaph- 
thalein  as  a  test  for  activity  of  the  kidneys;  scarlet-red  for  stimulat- 
ing healthy  and  rapid  growth  of  skin  over  surfaces  denuded  by  burns 
or  other  accidents;  acriflavine,  but  recently  recommended  in* solution 
as  a  surgical  dressing  for  extensive  wounds,  to  be  used  in  a  manner 
similar  to  the  sodium  hypochlorite  solution,  known  as  Dakin's  Solu- 
tion, being  destructive  to  bacteria  in  high  dilution  and  apparently 
harmless  to  living  tissues ;  malachite  green  proposed  and  widely 
experimented  with  for  the  same  purposes;  or  methylene  blue,  so 
extensively  used  in  certain  types  of  urethritis. 
Physical  chemistry  lends  its  aid  in  the  production  of  such  reme- 
dial agents  as  colloidal  solutions  of  silver,  mercury,  sulphur,  etc.,  ob- 
tained either  by  direct  electrolytic  action  or  in  the  presence  of 
proteins,  and  adds  to  our  slowly  acquired  empirical  knowledge  of 
emulsions  an  understanding  of  the  reasons  why,  and  the  conditions 
under  which  the  best  results  may  be  obtained. 
Radiochemistry  finds  its  pharmaceutical  application  in  the  use 
of  ultra-violet  rays  for  sterilizing  water  or  various  solutions,  or  the 
employment  of  radium  salts  and  radioactive  solutions  in  the  treat- 
ment of  various  diseases,  notably  cancer. 
The  petroleum  industry .  gives  to  the  pharmaceutical  ■  chemist 
solid  and  liquid  petrolatum  of  varying  degrees  of  purity  ranging 
from  cruder  petrolatum  for  veterinary  ointments  to  the  most  highly 
purified  liquid  oil  intended  for  human  use  as  an  intestinal  lubricant, 
and  paraffin  as  an  ingredient  of  ointments  or  base  of  surgical  dress- 
ings for  application  to  extensive  superficial  wounds  or  burns. 
The  consideration  of  oils  and  fats,  both  vegetable  and  animal, 
applied  one  way  or  another  to  medicinal  use,  opens  up  another  wide 
range  through  which  our  chemical  investigations  may  lead  us,  in- 
cluding such  things  as  the  familiar  castor  and  cod-liver  oils ;  the 
intensely  active  cathartic,  croton  oil ;  that  relic  of  old-time  pharmacy, 
citrine  ointment,  made  from  lard,  nitric  acid,  and  mercury  by  a 
process  similar  to  the  familar  elaidin  test  for  olive  oil;  the  com- 
paratively little  known  chaulmoogra  oil,  which  has  been  used  with 
