24 



burned and destroyed as they entered, lie allowed the air to have 

 free access to the tube. Beef-tea kept in this manner was found at 

 the expiration of some months to be perfectly sweet, but when the 

 neck of the tube was broken off and boiling heat no longer main- 

 tained, the liquid was quickly decomposed, and in twenty-four 

 hours swarmed with bacterial life. Thus whs demonstrated the 

 fact that decomposition is due to the micro-organisms which throng 

 the air, and not to any power of spontaneous generation in the 

 liquid itself. 



Dr. Bastian, however maintained that by his experiments it 

 "was equally well proved that a decomposable fluid placed in 

 sterilised tubes, boiled, and then hermetically sealed, was capable 

 of setting up spontaneous generation. The balance of scientific 

 opinion was, however against him, and M. Pasteur's theory was 

 fully confirmed by Professor Tyndall, who showed by many 

 elaborate experiments that the most decomposable liquids, if first 

 sterilised by boiling, and then effectually secluded from the air by 

 cotton wool, would keep good for an indefinite period. He also 

 demonstrated that if, after being boiled, they were simp'y kept at 

 an extreme altitude, where the air is free from germs, they are 

 equally proof against decomposition 



These experiments are, to my mind, deeply interesting, for I 

 confess I am one of those who cannot believe in the chemical 

 origin of even the lowest forms of life. T believe that even in the 

 very humblest organism exists a vital power, not only different 

 from, but, as we see in our own bodies, even opposed to chemical 

 action. We may not be able to define this marvellous power, or to 

 say in what it consists, but we see and feel its might, and our own 

 minds recognise it as that breath of life which emanated from a 

 supreme being. Life can never be a mere heterogeneous collection 

 of atoms ; there must be some guiding influence, directing each 

 tiny particle to the place it is to fill in the grand and harmonious 

 scheme of nature. Nothing in creation is more calculated to 

 excite our emotions of wonder and awe than the knowledge that 

 two tiny molecules of precisely similar appearance are destined, 

 perhaps, to develop, the one into a sentient and immortal man 

 with all his wonderful apparatus of ever beating heart, active and 

 reflecting brain, and complex organisation, and the other into 

 merely a simple lichen clinging to some weather beaten stone. 



M. Pasteur having identified the special fungus or yeast ferment 

 which transforms brewers' wort into beer, he was able readily to 

 detect, by the aid of the microscope, the other germs which so 

 frequently turned the beer sour, and spoiled the brewing. These 

 injurious microbes with which the air of a brewery teems in conse- 

 quence of the decomposable nature of many of the materials used, 



