38 BREAD, CHARCOAL, ETC. 



however, in such vast quantities as is required for vegetables may be a 

 matter of wonder ; but on an examination of the natural resources and 

 a glance at the views of Leibeg this wonder will cease. The grains 

 of one season in this country, must afford by the straw many thousands 

 of tons of carbon. Yet this is but a limited resource compared with 

 the quantity yielded by other vegetable productions, the combustion of 

 coal and other fuel, and by expirations from, and decomposition of 

 animals. The amount of carbonic acid gas emitted from the lungs of 

 a healthy person in 24 hours is 40,000 cubic inches, or 11 oz. of solid 

 carbon. Thus about 100 tons of solid carbon are exhaled in this 

 city every 24 hours from man alone. The facility with which it 

 blends in the air, notwithstanding its superior gravity, prevents those 

 deleterious effects on animal life which we might otherwise experience. 



The formation of proximate principles, such as we have before 

 mentioned, requires carbon to unite with oxygen and hydrogen in the 

 proportion in which they form water. Thus 100 parts of sugar is 

 composed of 40 carbon and 60 water; starch 41 carbon and 59 water; 

 gums 42 carbon and 58 water ; acetic acid 47 carbon and 53 water, 

 and wood 50 carbon and 50 water, with small proportions of other 

 elements. Starch and paper may be converted into gum, wood into 

 acetic acid, woody fibre into gelatin, starch 'nto sugar and wood into 

 starch. As flour is principally composed of starch, wood, in being 

 converted into starch, is converted into the principle constituent of 

 bread. It is known that a pound of starch may be converted into 

 more than a pound of sugar, simply by boiling it, diluted with water. 

 Letting the water and starch stand together will in time produce the 

 same results. 12,00 parts of water with 100 of starch, allowed 

 to stand two months, yields sugar 48 parts, gum 24, and starch 22. 



Bread may be made of beech saw-dust, carefully roasted to a pale 

 brown, kneeded with yeast and baked in the common way. It will 

 be seen that a small difference exists in the elementary constituents 

 of the before mentioned bodies, and that these differences may be cor- 

 rected by heat and by the addition of an acid or by the abstraction of 

 carbon and oxygen, when those substances may be converted from one 

 to another. Most vegetable substances contain sugar in greater or 

 less quantities. When sugar is produced a partial conversion of the 

 woody fibre takes place during the first fermentation. 



Charcoal, as we have said, is the purest state of carbon next to the 

 diamond ; and it may appear singular that these two states of this 

 element are derived from two entirely different kingdoms. It is ob- 

 tained, as may be known, by driving off, under cover of earth and 

 through the agency of a uniform and moderate heat, all the aqueous, 

 alkaline, volatile and resinous parts, leaving the carbon of the wood 

 alone. Its uses in the arts as well as for fuel are of the greatest im- 

 portance. In the manufacture of gunpowder, the lightest, most compact 



