if it were said by the Almighty, " Let there be progeny," and straight it is so ?
Let physicians, therefore, cease to wonder at what always excites their astonishment, namely, the manner in which epi- demic, contagious, and pestilential diseases scatter their seeds, and are propagated to a distance through the air, or by some 1 fomes ' producing diseases like themselves, in bodies of a different nature, and in a hidden fashion silently multiplying themselves by a kind of generation, until they become so fatal, and with the permission of the Deity spread destruction far and wide among man and beast ; since they will find far greater wonders than these taking place daily in the generation of animals. For agents in greater number and of more efficiency are required in the construction and preservation of an animal, than for its destruction ; since the things that are difficult and slow of growth, decay with ease and rapidity. Seneca x ob- serves, with his usual elegance, " How long a time is needed for conception to be carried out to parturition ! with what la- bour and tenderness is an infant reared ! to what diligent and continued nutrition must the body be subject, to arrive at adolescence ! but by what a nothing is it destroyed ! It takes an age to establish cities, an hour to destroy them. By great watching are all things established and made to nourish, quickly and of a sudden do they fall in pieces. That which becomes by long growth a forest, quickly, in the smallest interval of time, and by a spark, is reduced to ashes." Nor is even a spark necessary, since by the solar rays transmitted through a small piece of glass and concentrated to a focus, fire may be immediately produced, and the largest things be set in flames. So easy is every thing to nature's majesty, who uses her strength sparingly, and dispenses it with caution and foresight for the commencement of her works by imperceptible additions, but hastens to decay with suddenness and in full career. In the generation of things is seen the most excellent, the eternal and almighty God, the divinity of nature, worthy to be looked up to with reverence ; but all mortal things run to destruction of their own accord in a thousand ways.
1 Nat. Quaest. lib. iii, cap. 27.
