Composition of the Potato. 199 
Composition of the Phosphates. 
Phosphate of per oxide of iron, - 7-900 
lime, - - 2-933 
magnesia, - - -055 
silicic acid, - - trace. 
Phosphoric acid, - - 27-612 
Phosphate, 38-500 
It will be observed that the phosphates and alkalies abound, as 
soda and potash, and that the former (soda) is found in combina- 
tion with chlorine, forming common salt. Sulphuric acid, also, 
is another element which enters quite largely into the potato. 
2. Composition of the Scotch Grays. Analyzed by Mr. Balh 
Organic analysis gives the following results: 
Water, - - - - 71-63 
Starch, . . - . 9-28 
Albumen, ... - 0-92 
Casein, . - - . -20 - 
Dextrin, .... -40 
Sugar and extract, - - - 3-64 
Gluten and fat, - - - -40 
Fibre, ... - 11-39 
98-86 
Per cent, of Ash, - - - 1-12 
99-98 
The vScotch Gray is an excellent potato, being heavy, firm, and 
not much inclined to decay. It will be observed that it contains 
less water than the Mercer, and that it is rich in the valuable or 
nutritive elements. 
The Mountain June or Early July is another excellent potato. 
The following exhibits its orsfanic constitution: 
Water, - . . . 74-902 
Starch, - - - - 13-378 
Casein, - . - . 2-053 
Albumen, ... -085 
Sugary matter, . _ - 1-364 
Dextrin, - - - -912 
Fibre, .... 6-827 
Gluten and fat, ... -008 
99-529 
