530 
Fourth  Report  on  the  Analysis 
The  two  next  tables  give  the  composition  of  these  ashes : — 
Composition  in  100  parts  of  the  Ash  of  Potatoes  : — 
Specimen 
No.  1. 
Specimen 
No.  2. 
Specimen  . 
No.  3. 
Silica 
5-46 
1 -18 
•91 
Phosphoric  Acid  . 
15-10 
17-68 
17-15 
Sulphuric  Acid 
1-70 
3-31 
3-19 
Carbonic  Acid  . 
10-97 
7-30 
12-14 
Lime 
4-50 
3-76 
2-65 
Magnesia  .... 
5-70 
3-87 
4-21 
Peroxide  of  Iron 
•29 
2-11 
1-06 
Potash 
50-88 
50-93 
50-89 
Soda 
none. 
none. 
2-41 
Chloride  of  Potassium  . 
5-01 
8-98 
none. 
Chloride  of  Sodium  . 
•29 
•88 
5-38 
Total  .... 
99-98 
100-00 
99-99 
The  total  quantity  of  sulphur  in  1000  grs.  of  potatoes  undried 
was — 
£ No.  1.  No.  2.  No.  3. 
•035  -043  -063 
Composition  in  100  parts  of  the  Ash  of  Potato  Haulm: — 
Silica 
Phosphoric  Acid  . . 
Sulphuric  Acid 
Carbonic  Acid  . . 
Lime  . . . . . 
Magnesia  . 
Peroxide  of  Iron 
Potash 
Soda 
Chloride  of  Potassium  . 
Chloride  of  Sodium 
Total  . . . . 
No.  1. 
No.  2. 
2-20 
8-22 
6-62 
2-27 
4-58 
5-12 
11-46 
14-09 
29-86 
37-02 
5-46 
6-00 
3-89 
3-78 
10-07 
11-44 
none. 
none. 
21-08 
traces. 
4-77 
12-06 
99-99 
100-00 
The  total  sulphur  in  1000  grs.  of  the  undried  potato  haulm 
was — 
No.  1.  No.  2. 
Not  determined.  *029 
The  analyses  now  given  of  potatoes  will  serve  to  point  out  their 
general  characters ; they  do  not  call  for  any  particular  remark  in 
this  place. 
Grasses. 
The  examination  of  the  natural  grasses  has  always  presented 
