p.7

7

Liebig divides the cultivated plants as follows
Alkali plants-as Potatoes, Beets &c
Lime plants-as Clover, Pears &c
Silex plants, the Grasses
Phosphorus plants-Rye, wheat &c-
Probably the last should have been Silico-phosphorus, plants as they contain both substances.

[Line crossed out]

Grasses are fewest at the Equator, and increase gradually towards the poles-

There are about 4000 species of grasses, of which only about 70 are cultivated as food for man.

[Schleider' Boussingault multiplies the number of days a plant requires to grow, by the mean temperature of the same period, which may be considered the quantity of heat required by the plant. Hence a greater heat requires a less time, and a lesser heat a longer time to perfect any given plant-[Summer heat therefore regulates the growth of plants not the mean nor the [winter?] temperature.

A curious inquiry perhaps worth carrying out!

Barley Most northern grain 65 deg. 60. Oats.
Rye-next
Wheat-The Indian corn next [lat 60] -51-
Rice next-37-

7

Liebig divides the cultivated plants as follows
Alkali plants-as Potatoes, Beets &c
Lime plants-as Clover, Pears &c
Silex plants, the Grasses
Phosphorus plants-Rye, wheat &c-
Probably the last should have been Silico-phosphorus, plants as they contain both substances.

[Line crossed out]

Grasses are fewest at the Equator, and increase gradually towards the poles-

There are about 4000 species of grasses, of which only about 70 are cultivated as food for man.

[Schleider' Boussingault multiplies the number of days a plant requires to grow, by the mean temperature of the same period, which may be considered the quantity of heat required by the plant. Hence a greater heat requires a less time, and a lesser heat a longer time to perfect any given plant-[Summer heat therefore regulates the growth of plants not the mean nor the [winter?] temperature.

A curious inquiry perhaps worth carrying out!

Barley Most northern grain 65 deg. 60. Oats.
Rye-next
Wheat-The Indian corn next [lat 60] -51-
Rice next-37-