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 carefulb 

 corked and sealed with mastic; by subjecting the sealcc 

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

 due course of time, the fluids thus treated became infecte( 

 with microscopic life, and, inasmuch as Needham believ< 

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

 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 know; 

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

 actively engage in his churchly offices, but, following an innat< 

 love of natural science and .of investigation, devoted himsel 

 to experiments and researches and to teaching. He was fin 

 a professor at Bologna, and afterward at the University ci 

 Pavia. He made many additions to knowledge of th< 

 development and the physiology of organisms, and he was 

 the first to make use of glass flasks in the experimental stud; 

 of the' question of the spontaneous generation of life. 



Spallanzani thought that the experiments of Needhai 

 had not been conducted with sufficient care and precision; 

 accordingly, he made use of glass flasks with slender necl 

 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 mad( 

 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- 



