. How crops grow. A treatise on the chemical composition, structure, and life of the plant, for all students of agriculture ... Agricultural chemistry; Growth (Plants). 34 HOW CROPS GROW. ash. Exposed to heat, this body melts, and presently evolves oxygen in great abundance. Exp. 4.—The following fiuTirc illustrates the apparatus employed for preparinij and collecting this gas. A tube of difficultly fusible ^'lass, 8 inches Ion;? and J^ inch wide, con- tains the oxide of mercury or chlorate of potash.* To its mouth is con- nected, Mir-tisht, by a cork, a narrow tube, the free extremity of whic
. How crops grow. A treatise on the chemical composition, structure, and life of the plant, for all students of agriculture ... Agricultural chemistry; Growth (Plants). 34 HOW CROPS GROW. ash. Exposed to heat, this body melts, and presently evolves oxygen in great abundance. Exp. 4.—The following fiuTirc illustrates the apparatus employed for preparinij and collecting this gas. A tube of difficultly fusible ^'lass, 8 inches Ion;? and J^ inch wide, con- tains the oxide of mercury or chlorate of potash.* To its mouth is con- nected, Mir-tisht, by a cork, a narrow tube, the free extremity of which passes under the shelf of a tub nearly filled with water. The shelf has beneath, a sauc'cr-shaped cavity opening above by a narrow orifice, over which a bottle filled with water is inverted. Heat being applied to the. Fig. 3. wide tube, the common air it contains is first expelled, and presently, oxygen bubbles rapidly into the bottle and displaces the water. When the bottle is full, it may be corlicd and set aside, and its place supplied by another. Fill four pint bottles with the gas, and set them aside with their mouths in tumblers of water. From one ounce of chlorate of pot- ash about a gallon of oxygen gas may be thus obtained, which is not quite pure at first, but becomes nearly so ou standing over water for some hours. "When the escape of gas becomes slow and cannot be quickened by increased heat, remove tlie delivery-tube fmm the water, to prevent the latter receding and breaking the apparatus. * The chlorate of potash is best mixed with about one-qnarter its weight of powdered black oxide of manganese, as thi? facilitates the preparation, and ren- ders the heat of a common spirit lamp sufEcicnt. Digitized by Microsoft®. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Johnson, Samuel Willia
Size: 1738px × 1438px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, booksubjectagricul, bookyear1868
