PART I. GENERAL 



HISTORICAL INTRODUCTION. 



BIOLOGY, chemistry, medicine, and surgery, in their evolu- 

 tion, contributed to a new branch of knowledge, Bacteri- 

 ology, whose subsequent development has become of in- 

 estimable importance to each. Indeed, bacteriology illus- 

 trates the old adage, " The child is father of the man," 

 for while it is in part the offspring of the medicine of the 

 past, it has established itself as the dictator of the medicine 

 of the present and future, especially so far as concerns the 

 infectious diseases. 



THE EVOLUTION OF BACTERIOLOGY. 



I. BIOLOGIC CONTRIBUTIONS j THE DOCTRINE OF SPONTANEOUS 

 GENERATION. 



Among the early Greeks we find that Anaximander 

 (43d Olympiad, 610 B. C.) of Miletus held the theory that 

 animals were formed from moisture. Empedocles of 

 Agrigentum (450 B. C.) attributed to spontaneous genera- 

 tion all the living beings which he found peopling the 

 earth. Aristotle (384 B. C.) is not so general in his view 

 of the subject, but asserts that "sometimes animals are 

 formed in putrefying soil, sometimes in plants, and some- 

 times in the fluids of other animals." 



Three centuries later, in his disquisition upon the Pytha- 

 gorean philosophy, we find Ovid defending the same doc- 

 trine of spontaneous generation, while in the Georgics Virgil 

 gives directions for the artificial production of bees. 



The doctrine of spontaneous generation of life was not 

 only current among the ancients, but we find it persisting 

 through the Middle Ages, and descending to our own genera- 

 tion. In 1542, in his treatise called " De Subtilitate," we 



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