Dimorphism, b. [336].

Dioptra, a. [165].

Dipolarization, b. [80], [82].

Direct motion of planets, a. [138].

Discontinuous functions, b. [36].

Dispensatoria, b. [366].

Dispersion (of light), b. [126].

Doctrine of the sphere, a. [130].

Dogmatic school (of medicine), b. [439].

Double refraction, b. [69].