154 
GARDENING AS A SCIENCE. 
But gum, while such, is gum, and nothing else ; no chemist could by any 
human means so re-combine the elements oxygen, hydrogen, and carbon, as to 
give them the form of gum. In truth, by the energy of heat, and the attraction 
of re-agents employed, a substance (as gum) is electrolysed, rent, and torn to 
pieces, and converted to gases. As, however, analysis acts equally on all the 
substances submitted to its energy, the gaseous, liquid, or solid products so 
obtained, become standards of comparison ; and thereby we obtain data whence to 
infer that the real natural elements must, to a very great extent, correspond with 
their developed representatives. 
2. Starchy according to the same authorities, yields to analysis — 
Carbon . . 43-55 Or in another view — Carbon . . . 43*55 
Oxygen , . 49-68 Oxygen and Hydrogen in the proportions toi ^g.^^ 
Hydrogen . 6-77 form water . . . . • • J 
100 100 
Starch forms a principal part of a number of esculent vegetable substances, 
Sowans, Cassava, Salop, Sago, and all of them owe their nutritive powers princi- 
pally to starch. 
Potatoes contain much starch {Amylum)^ the quantity varying from about 
one-eighth to one-sixth of the pulp ; and from this product, or perhaps from the 
pulp itself, sugar can be, and we believe, is, prepared to a considerable extent. 
The French are now in the habit of strengthening their clarets with starch sugar 
in those bad, moist seasons when the grape-juice is deficient of the saccharine 
principle ; and, as this sugar is analogous to grape sugar, it might be desirable to 
substitute it, in wine-making, for the less wholesome and congenial sugar of the 
*' Cane," which experience proves to be improper for the preparation of our own 
grape, currant, and other fruit wines. 
" 3. Sugar, according to the recent experience of Gay-Lussac and Thenard, 
consists of 42*47 of carbon, and 57'58 of water or its elements. Lavoisier and 
Dr. Thompson's analyses agree very nearly with the proportions of 3 carbon, 4 of 
oxygen, and 8 hydrogen" (i. e., in atomic equivalents). 
Thus, upon every authority, sugar, starch, and gum agree closely in their 
developed elements ; and, therefore, we need not be surprised that sugar may 
be readily produced from starch, and that all can be converted into oxalic 
acid. 
4. " Albumen is a substance common to the animal as well as to the vegetable 
kingdom." So Davy asserted, soon after its discovery in the kernel of the Almond, 
Peach-nut, &c. ; and the identity with animal albumen has been proved by Liebig 
and other modern chemists. Like the white of egg, which furnishes the most 
familiar example of animal albumen, that obtained from vegetables is coagulated 
by the action of heat or acid, when mixed with water, even when 1 grain only is 
diffused through 1,000 grains of water. Albumen is an azotised product ; hence 
its approach to the quality of human blood, 100 parts of white of egg yield of 
