Emil Chr. Hansen 5 Særtryk 1901-1909

HANSEN : CONSIDERATIONS ON TECHNICAL MYCOLOÖY. 58Ö extract in closed flasks, and, since organisms developed in these flasks, he considered that they must have been produced by spontaneous generation. Buffon, and a large number of other naturalists, adopted his doctrine. There were, however, some opponents to it, the most celebrated of whom was Spallanzani. In 1765 he commenced the publication of a series of researches controverting the view upheld by Needham. The flasks with which he made his experiments were closed hermetically and placed in a vessel of boiling water, the high temperature being maintained for about an hour. No micro-organisms appeared after this treatment, not even after they had been cooled; when, however, air was allowed to enter, growth at once occurred. Spallanzani concluded from his experiments that spontaneous genera- tion did not take place, and that the germs, or, as he called them, the eggs, for the development of micro-organisms were present in the air. When these gained access to the decoctions with which he and Needham experimented, their further development ensued. This contest, after languishing for some time, was then taken up with renewed vigour. Schwann embraced Spallanzani’s view, whereas Kützing took Needham’s, which Cagniard Latour also seems to have done. The dispute was kept going for a considerable time with ever varying chances as to who should carry off the final victory; and no small number of distinguished scientists became participants in it as time went on. Much has been written on this subject, and it is here only possible for me to deal with the main issüe; I have also elsewhere treated more fully of it. Schwann had shown that different substrata, easily affected by fermentation or putrefaction, would keep when boiled, and that, after having been subjected to that process, they would remain unaltered, even if air was allowed to enter into contact with them, only provided it had been deprived beforehand of all the germs it carried by means of heating. He had then gone one step farther than Spallanzani. In his papers, dating from the year 1839, he furthermore showed that yeast cells perish when they are acted upon by chemical compounds, and he thus laid the foundation of the doctrine of antiseptics, which also subsequently became of such importance in technical mycology. In spite of the experiments carried out by Schwann and other scientists, some obscurity still prevailed, and the adherents of spontaneous generation availed themselves of this. We owe it to the brilliant and penetrating researches of Pasteur