282 BIOLOGY AND ITS MAKERS 



were conducted by extracting the juices of meat by boiling; 

 by then enclosing the juices in vials, the latter being carefully 

 corked and sealed with mastic; by subjecting the sealed 

 bottles, finally, to heat, and setting them away to cool. In 

 due course of time, the fluids thus treated became infected 

 with microscopic life, and, inasmuch as Needham believed 

 that he had killed all living germs by repeated heating, he 

 concluded that the living forms had been produced by spon- 

 taneous generation. 



Spallanzani. The epoch-making researches of Spallan- 

 zani, a fellow-countryman of Redi, were needed to point out 

 the error in Needham's conclusions. Spallanzani (Fig. 90) 

 was one of the most eminent men of his time. He was 

 educated for the church, and, therefore, he is usually known 

 under the title of Abbe Spallanzani. He did not, however, 

 actively engage in his churchly offices, but, following an innate 

 love of natural science and of investigation, devoted himself 

 to experiments and researches and to teaching. He was first 

 a professor at Bologna, and afterward at the University of 

 Pavia. He made many additions to knowledge of the 

 development and the physiology of organisms, and he was 

 the first to make use of glass flasks in the experimental study 

 of the question of the spontaneous generation of life. 



Spallanzani thought that the experiments of Needham 

 had not been conducted with sufficient care and precision; 

 accordingly, he made use of glass flasks with slender necks 

 which could be hermetically sealed after the nutrient fluids 

 had been introduced. The vials which Needham used as 

 containers were simply corked and sealed with mastic, and 

 it was by no means certain that the entrance of air after 

 heating had been prevented ; moreover, no record was made 

 by Needham of the temperature and the time of heating to 

 which his bottles and fluids had been subjected. 



Spallanzani took nutrient fluids, such as the juices of vege- 



