Part 10

Decurrent. Extending downward, as the base of a leaf.

Dehydrate. Remove water, dry.

Dendrology. The scientific study of trees.

Devonian. Of the geological formation between the Silurian and the Carboniferous.

Dew point. The temperature at which the air is saturated with water-vapor.

Diadelphous. Formed into two bundles. (Of stamens.)

Diandrous. With two stamens.

Dielectric. Insulating, insulator of electricity.

Diesel engine. An internal combustion motor which compresses the air highly and which successfully burns oil which is unsuitable for the ordinary motor of an automobile.

Disease. Malady. Of some foods and drinks, an impairment in quality caused by bacteria.

Dissipation of energy. The change of energy to such a form that it cannot be used to do work.

Dissociate. Ionize, decompose, split up.

Doldrums. A region of calms and light winds near the equator.

Dolichocephalic. Long-headed, having a skull with the breadth less than four-fifths of the length.

Drug. A medicine, a medicinal agent, especially one of vegetable origin.

Dynamics. The branch of physics dealing with forces.

Dyne. The amount of force that acts for a single second on a mass of one gram to give it a velocity of one centimeter per second.

Eccentric. Not concentric to a given circle. Arranged to change rotary motion back and forth.

Echinoderm. One of a class of animals including the sea-urchins.

Eclipse. Of a heavenly body, obscured by passing between it and the observer or its source of light.

Ecliptic. The apparent orbit of the sun.

Ecology. The science dealing with the relations between organisms and their environment.

Economics. The science of wealth, especially of its production, distribution, and consumption.

Edentate. Toothless or without canine teeth.

Effect. See Cause.

Efferent. Carrying outward or away.

Efficiency. The ratio between the amount of work put into a machine and the amount derived from it.

Efflorescence. The loss of water of crystallization.