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ior of organic cells, either containing air, or a pellucid watery liquid, or some special chemical secretions of the cell protoplasm. Contractile vacuole. (Zoöl.) See under Contractile, and see Illusts. of Infusoria, and Lobosa. -- Food vacuole. (Zoöl.) See under Food, and see Illust. of Infusoria.

with a brush, or otherwise. When applied the varnish soon dries, either by evaporation or chemical action, and the resinous part forms thus a smooth, hard surface, with a beautiful gloss, capable of resisting, to a greater or less degree, the influences of air and moisture.

A large vessel, cistern, or tub, especially one used for holding in an immature state, chemical preparations for dyeing, or for tanning, or for tanning leather, or the like. Let him produce his vase and tubs, in opposition to heaps of arms and standards. Addison.

A probable chemical element discovered by Sir William Crookes in 1898. Its nitrate is obtained byy practical decomposition and crystallization of yttrium nitrate. At. wt., about 117.

hich the visual rays unite; the position of the eye. -- Visual purple (Physiol.), a photochemical substance, of a purplish red color, contained in the retina of human eyes and in the eyes of most animals. It is quickly bleached by light, passing through the colors, red, orange, and yellow, and then disappearing. Also…

he functions of a living organism are due to an unknown vital principle distinct from all chemical and physical forces.

ning to Alessandro Volta, who first devised apparatus for developing electric currents by chemical action, and established this branch of electric science; discovered by Volta; as, voltaic electricity.

That form of electricity which is developed by the chemical action between metals and different liquids; voltaic electricity; also, the science which treats of this form of electricity; -- called also galvanism, from Galvani, on account of his experiments showing the remarkable influence of this agent on animals.…

voltaic electricity passing through it, by its effect in decomposing water or some other chemical compound acting as an electrolyte.

or exhibiting to the eye the changes of volume of a gas or gaseous mixture resulting from chemical action, and the like.

ly regarded in certain mathematical speculations as the typical form and structure of the chemical atom. -- Vortex wheel, a kind of turbine.

er, by the process of vulcanization. Vulcanized fiber, paper, paper pulp, or other fiber, chemically treated, as with metallic chlorides, so as to form a substance resembling ebonite in texture, hardness, etc. Knight. -- Vulcanized rubber, India rubber, vulcanized.

ng silver ores by grinding in pans or tubs with the addition of mercury, and sometimes of chemicals such as blue vitriol and salt.

k.(Chem.) A round concavo-convex glass of shallow depth used for certain manipulations of chemicals in a laboratory. -- Watch guard, a chain or cord by which a watch is attached to the person. -- Watch gun (Naut.), a gun sometimes fired on shipboard at 8 p. m., when the night watch begins. -- Watch light, a low-burn…

A suffix used as a characteristic termination of chemical radicals; as in ethyl, carbonyl, hydroxyl, etc.

Animal chemistry; particularly, the description of the chemical compounds entering into the composition of the animal body, in distinction from biochemistry.

A mother substance, or antecedent, of an enzyme or chemical ferment; -- applied to such substances as, not being themselves actual ferments, may by internal changes give rise to a ferment. The pancreas contains but little ready-made ferment, though there is present in it a body, zymogen, which gives birth to the fermen…

t of the Bacterium lactis, which sets up certain fermentative processes by which definite chemical products are formed; -- distinguished from a pathogenic organism. Cf. Micrococcus.