248 
Pharmacy  of  Calcium  Glycerophosphate.    {  Aful°nrig^jarm' 
In  5  per  cent,  alcohol 
In  10  per  cent,  alcohol 
In  12  per  cent,  alcohol 
1  :  41.6 
1 :  55-6 
1 :  66.6 
assuming  that  the  composition  of  the  precipitate  is  the  same  as  that 
of  the  original  salt.  The  method  here  employed  gives  quantitative 
results  only  for  the  case  where  the  solute  is  in  excess  as  before 
stated.  It  does  show,  however,  that  small  amounts  of  alcohol 
markedly  repress  the  solubility  of  the  salt. 
2.  Influence  of  Acids  upon  the  Solubility  of  Calcium  Glycero- 
phosphate in  Dilute  Alcohol. — A.  To  25  mils  of  the  saturated  solu- 
tion used  in  the  first  series  0.33  mil  of  lactic  acid  was  added. 
Alcohol  was  now  added  drop  by  drop  and  thoroughly  mixed  in  until 
a  permanent  cloudiness  was  produced.  The  total  volume  was  31.9 
mils.  Allowing  3  per  cent,  for  shrinkage  the  alcoholic  content  of  the 
mixture  was  nearly  23  per  cent,  by  volume  and  the  solubility  was 
about  1  : 40.  Thus,  1  per  cent,  of  lactic  acid  increases  the  solubility 
of  the  salt  so  that  23  per  cent,  alcohol  equals  the  solvent  power  of 
5  per  cent,  alcohol  without  such  addition. 
B.  To  the  foregoing  0.9  mil  of  lactic  acid  was  added  which 
redissolved  the  precipitate.  Alcohol  was  added  to  permanent  cloudi- 
ness as  before.  The  final  volume  was  101  mils  and  the  alcoholic 
content  nearly  72  per  cent.  The  acid  concentration  was  1.22  per 
cent,  and  the  solubility  about  1  :  128.  Without  the  acid  calcium 
glycerophosphate  would  be  scarcely  soluble  at  all  in  72  per  cent, 
alcohol. 
C.  To  25  mils  of  the  saturated  solution  3.5  mils  (12  per  cent.) 
of  alcohol  were  added.  A  precipitate  occurred  which  was  redis- 
solved by  0.2  Gm.  citric  acid.  Within  twenty-four  hours  a  crystal- 
line precipitate  of  calcium  citrate  appeared. 
D.  To  25  mils  of  the  saturated  solution  3.5  mils  of  alcohol  were 
added  and  0.6  mil  of  U.  S.  P.  phosphoric  acid  were  used  to  redis- 
solve  the  precipitate.  This  solution  became  cloudy  in  a  short  time, 
but  did  not  deposit  a  precipitate. 
E.  To  25  mils  of  the  saturated  solution  3.5  mils  of  alcohol  were 
added.  0.6  mil  of  lactic  acid  redissolved  the  precipitate.  Solution 
has  remained  clear  for  three  months. 
3.  Influence  of  Glycerin  upon  the  Solubility  and  Hydrolysis. — 
A.  To  75  mils  of  the  saturated  solution  25  mils  of  glycerin  were 
added.  In  8  days  the  solution  became  cloudy;  in  7  days  more  a 
precipitate  settled  out. 
