. A Manual of botany : being an introduction to the study of the structure, physiology, and classification of plants . Botany. 786 PEEPAEATION OF The asphalte is applied by means of a hair pencil, the slide being placed on a turn-table (fig. 954), which has circular marks on it corre- sponding to the required dimensions of the cavity. The depth of the cavity can be varied according to circumstances, by putting one or more layers of asphalte. After the thin glass cover is put on, it is luted carefully with asphalte. The cavity is filled with distilled water, weak pyroligneous acid, alco
. A Manual of botany : being an introduction to the study of the structure, physiology, and classification of plants . Botany. 786 PEEPAEATION OF The asphalte is applied by means of a hair pencil, the slide being placed on a turn-table (fig. 954), which has circular marks on it corre- sponding to the required dimensions of the cavity. The depth of the cavity can be varied according to circumstances, by putting one or more layers of asphalte. After the thin glass cover is put on, it is luted carefully with asphalte. The cavity is filled with distilled water, weak pyroligneous acid, alcohol, diluted glycerine, a very weak solution of creazote (one drop to the ounce of distilled water), or some other fluid. When specimens are very minute the asphalte cell is not required; the thin glass is applied at once to the slide, a drop or two of the fluid being ioserted along with the specimen. In the case of some dry preparations, as pollen-grains and the fine-lined Diatoms, no fluid whatever is required, but precautions must be taken against the access of damp. Canada balsam is useful in some instances. The specimen is laid on a slide,'then a drop of the solution of Canada balsam is put on it, and the thin glass above all. It is then set aside to dry, and ultimately a rim of asphalte is made round the margin of the glass cover. Canada balsam is well fitted for many Diatoms, and for thin sections of woods. In putting up woods, the specimen is placed in the centre of the slide, a drop of turpentine is insinuated below it, with a camel- hair pencil, in order to expel the air; a solution of Canada balsam is then applied, and the same procedure is followed as above. To MAKE Cells, and to fix the thin Glass Covers.—The cells are made either round or square by thin layers of cement, according to the depth required. Perhaps the round ones are neater, but they require circular pieces of glass for covers, and by the aid of the turn- table (fig. 954) the roundness of the mounti
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
