ANALYSIS  OF  CHURCH-HILL  ALUM  WATER.  271 
r.     Ifl    AAA  nnrtnata 
In  IU,UUU  parts 
of  tlie  water. 
gaits, 
Su.lptiu.ric  _A.cid» 
Sulphate  of  potassa, 
0.419 
0.192 
SnliVhat.p  of  soda. 
0.333 
0.188 
Chloride  of  sodium, 
0.793 
Sulphate  of  ammonia, 
0.110 
0.077 
Sulphate  of  lime. 
15.219 
8.952 
Sulphate  of  magnesia, 
14.744 
9.827 
Sulphate  of  alumina,  (neutral,) 
12.494 
8.747 
Protosulphate  of  iron, 
4.281 
2.253 
Persulphate  of  iron,  (neutral,  • 
8.783 
5.270 
Persulphate  of  iron,  (|  basic,)  . 
14.280 
7.140 
Silica,  ..... 
1.787 
Phosphoric  acid, 
trace 
73.243 
42.648 
The  neutral  sulphates  of  alumina  and  peroxide  of  iron  have  the 
formulae  Fe2  03,  3S03  and  Al2Os  3S03 ;  and  the  basic  salt  has  the 
formula  Fe2  03,  2S03.  The  above  salts  may  be  thrown,  for  con- 
venience, into  the  three  following  groups  : 
Grains. 
Per  gallon.  Pergiil. 
Total  amount  of  alkaline  salts,      .       .      184  J      .       .  6 
"  salts  of  iron,        .  159 £  .  5 
"  persulphate  of  alumina,  73  .  2£ 
Of  the  alkaline  salts  nearly  one-half  is  Epsom  salts,  and  nearly 
one  half  of  the  iron-salts  consists  of  the  oxides  of  iron. 
We  have  carefully  compared  the  analysis  of  this  water  with  the 
analysis  of  a  large  number  of  the  alum-waters  of  Europe,  and  find 
only  four  of  them  which  will  compare  with  it  in  richness  of  solid 
content,  and  none  of  them  contain  the  ingredients  of  the  several 
classes  as  well  proportioned.  We  therefore  regard  it  as  one  of 
the  richest  and  best  proportioned  of  all  the  alum-waters  known. 
It  is  at  the  same  time  an  alterative,  astringent,  tonic  and  laxative. 
The  large  proportion  of  iron  salts  renders  it  an  excellent  tonic. 
The  aluminous  salt  tends  to  give  it  astringency,  but  this  effect  is 
modified  by  the  laxative  agency  of  the  alkaline  salts,  especially  of 
Epsom  salt.  The  combination,  as  a  whole,  makes  it  an  alterative. 
It  will  unquestionably  be  regarded  as  a  useful  adjuvant  to  the 
physician,  and  a  valuable  addition  to  the  materia  medica. 
