266  ON  THE  ALUM  SPRINGS  OF  VIRGINIA. 
vary  in  the  proportion  of  solid  constituents,  and  the  same  spring 
is  not  uniform  in  composition,  being  affected  by  rains.  The  fol- 
lowing analysis  of  spring  No.  2  was  made  by  Dr.  Hayes  of  Boston, 
the  quantity  examined  being  one  gallon : 
ouipnaie  oi  potasn 
1  76^ 
grs. 
Sulphate  of  lime 
3.263 
a 
Sulphate  of  magnesia 
1.763 
u 
Protoxide  of  iron 
4  QUO 
cc 
Alumina  - 
-  17.905 
a 
Crenate  of  ammonia  - 
0.700 
it 
Chloride  of  sodium 
1.008 
U 
Silicic  acid 
2.840 
et 
Free  sulphuric  acid 
-  15.224 
tc 
Free  carbonic  acid. 
7.536 
a 
56.867 
a 
Pure  water 
58315.133 
u 
58372.000  " 
The  diseases  in  which  this  water  has  most  reputation  are  dys- 
pepsia, scrofula,  chronic  diarrhoea  and  skin  diseases. 
The  Bath  Alum  Springs  are  located  about  17  miles  west  of 
the  Rockbridge  Springs,  in  Bath  County.  The  springs  are  six  in 
number,  and  issue  at  the  base  of  a  hill  only  15  or  20  feet  high, 
of  slate  formation.  The  following  is  Dr.  Hayes'  analysis  of  spring 
No.  3,  viz : 
Free  sulphuric  acid 
7.878 ; 
grs, 
Carbonic  acid 
3.846 
u 
Sulphate  of  potash 
0.258 
CC 
Magnesia  - 
1.282 
(6 
Lime  - 
2.539 
u 
Protoxide  of  iron 
-  21.776 
it 
Alumina 
12.293 
a 
Crenate  oi  ammonia  *  - 
1.776 
tt 
Silicate  of  soda 
3.150 
ct 
54.798 
iC 
Pure  water 
58317-202 
58372.000 
a 
