Am'ju°iy?i?9h3arm"}        Decomposition  of  Chloroform.  359 
by  the  varying  intensity  of  daylight,  as,  indeed,  Mr.  Dott  states  that 
he  has  found  to  be  the  case  in  regard  to  chloroform  of  1-498  sp.  gr. 
The  amount  of  alcohol  present  in  any  sample  of  chloroform  may 
be  inferred  with  accuracy  from  the  specific  gravity  of  the  sample  in 
question,  but  as  alcohol  does  not  reduce  the  gravity  in  exact  arith- 
metical ratio  to  its  amount,  we  have  found  it  necessary  to  determine 
the  specific  gravity  of  known  mixtures  of  absolute  alcohol  and 
chloroform.    In  that  way  we  have  obtained  the  following  data  : 
Specific  gravity 
at  150  C.  =  59°  P. 
Pure  chloroform    1  '5020 
"       with  C25  p.  C.  alcohol   i'4977 
"0-5"       "    1*4939 
"    i-o     "       "   1-4854 
"  "  "2-0"       "    1*4705 
According  to  these  data  the  chloroform  of  1-5  sp.  gr.  operated 
upon  by  Mr.  Brown  (see  ante,  p.  792)  would  have  contained  g~i-¥  of 
absolute  alcohol  (provided  its  specific  gravity  was  determined  at 
590  F.),  an  amount  which  is  in  close  correspondence  with  the 
observed  retardation  of  its  decomposition  under  the  influence  of 
oxygen  and  sunlight. 
In  reference  to  the  interesting  fact  of  the  accelerated  decompo- 
sition of  chloroform  in  an  atmosphere  of  pure  oxygen,  we  are 
disposed  to  ascribe  that  result  to  the  absence  of  the  nitrogen  with 
which  oxygen  is  mixed  in  ordinary  atmospheric  air.  At  one  time 
we  entertained  the  idea  that  ozonization  of  the  oxygen  in  contact 
with  chloroform  and  under  the  influence  of  sunlight  might  have 
something  to  do  with  the  decomposition,  but  that  was  during  the 
earlier  period  of  our  investigations,  and  the  experiments  made  in 
reference  to  this  point  during  1868  showed  that  no  ozonization  takes 
place. 
In  conclusion,  we  agree  with  Mr.  Brown's  opinion  that  the 
gradual  disappearance  of  free  chlorine  when  chloroform  is  under- 
going decomposition  is  a  sign  of  its  further  action  upon  the  chloro- 
form, producing  hydrochloric  acid  and  altering  the  relative  propor- 
tions of  carbon  oxychloride  and  hydrochloric  acid  so  as  to  increase 
the  latter. 
Magnesium  sulphate,  according  to  Dr.  Suckling,  administered  as  a 
-purgative  to  the  mother,  also  causes  looseness  in  the  nursling,  while  senna 
cascara  and  aloes  rarely  affect  the  child's  bowels. 
