Appendix, 



days he invariably found in the vials infusoria present in great 

 and constantly increasing numbers. His argument then was that 

 if they were produced from germs, the germs must exist either in 

 the substance which had been boiled, the water in which it was 

 boiled, or in the air enclosed in the vial. Now boiling destroys 

 the vitality of all germs, hence no infusoria should be developed 

 in his infusions. But they were invariably present in his vials 

 and accordingly he assumed that they were generated by a reor- 

 ganization of the dead animal matter. But as Huxley says, most 

 eloquently, "the great tragedy of science the slaying of a beau- 

 tiful hypothesis by an ugly fact which is so constantly being 

 enacted under the eyes of philosophers, was played almost imme- 

 diately for the benefit of Buffon and Needham." 



The Abbe Spallanzini* thought that Needham's experiments 

 had not been conducted with sufficient care and precision, as no 

 account had been taken of the absolute temperature to which the 

 flasks and infusions had been subjected, nor had the mouths of 

 the flasks been absolutely closed from contact with the external 

 air. He therefore took glass flasks partly filled with organic in- 

 fusions, and after closing them by hermetically sealing up the 

 necks, exposed them to the temperature of boiling waterf for an 



* LAZZARO : an Italian physician, born in the duchy of Modena, 1729, died 

 at Pavia, 1799. He was educated at Bologna, where he subsequently became 

 a Professor, and still later he was appointed to the Chair of Natural History 

 in the University at Pavia. He was one of the most eminent men of his day, 

 an honorary member of nearly all the learned societies of Europe, and uni- 

 versally held in the highest esteem. His scientific studies were principally 

 in physiology, especially of the lower animals; and by these studies which 

 have been incorporated into the text-books, his name is more familiar to 

 the medical student of to-day than that of many other recent observers. He 

 refused offers of Professorships in a number of the prominent institutions of 

 the time, among them the Jardin des Plantes in Paris. 



t Various expedients for ridding the flasks of any existing infusoria or 

 germs have been adopted by different experimenters. Those usually em- 

 ployed are 



1. Calcination causing air to pass through red-hot tubes. 



2. Filtration passing air through any substance which shall catch and 

 retain all foreign matters. 



3. $M&mtence-^-allowing the particles to settle by gravity. 



4. Expulsion driving out air and particles contained therein by hermet- 

 ically sealing neck of flask while contents are in an active state of ebullition. 



Two or even more of these methods may of course be combined in a sin- 

 gle experiment. The great difficulty of excluding all germs from the flasks by 



