346 LAY SERMONS, ADDRESSES, AND REVIEWS. [xv 



directly, to the working out, by seven generations of 

 patient and laborious investigators, of the thought 

 which arose, more than two centuries ago, in the mind 

 of a sagacious and observant Italian naturalist. 



It is a matter of every-day experience that it is 

 difficult to prevent many articles of food from be- 

 coming covered with mould ; that fruit, sound enough 

 to all appearance, often contains grubs at the core; 

 that meat, left to itself in the air, is apt to putrefy 

 and swarm with maggots. Even ordinary water, if 

 allowed to stand in an open vessel, sooner or later 

 becomes turbid and full of living matter. 



The philosophers of antiquity, interrogated as to 

 the cause of these phenomena, were provided with a 

 ready and a plausible answer. It did not enter their 

 minds even to doubt that these low forms of life were 

 generated in the matters in which they made their 

 appearance. Lucretius, who had drunk deeper of the 

 scientific spirit than any poet of ancient or modern 

 times except Goethe, intends to speak as a philoso- 

 pher, rather than as a poet, when he writes that " with 

 good reason the earth has gotten the name of mother, 

 since all things are produced out of the earth. And 

 many living creatures, even now, spring out of the 

 earth, taking form by the rains and the heat of the 

 sun." * The axiom of ancient science, " that the cor- 

 ruption of one thing is the birth of another," had its 

 popular embodiment in the notion that a seed dies 

 before the young plant springs from it ; a belief so 



1 It is thus that Mr. Munro renders 



" Linquitur, ut merito maternum nomen adepta 

 Terra sit, e terra quoniam sunt cuncta creata. 

 Multaque nunc etiam exsistant animalia terria 

 Imbribua et calido solis concreta vapoi*e." 



De Rerum Nalura, lib. v. 793-796. 



But would not the meaning of the last line he better rendered "Deve- 

 loped in rain-water and in the warm vapours raised by the sun" ? 



