82 FERMENTS AND MICRO -PARASITES. 



putrefaction was observed. In the same way in urine, 

 kept with certain precautions, an alkaline reaction and 

 commencing putrefaction were observed after some time 

 (Colin, Billroth, Hiller, &c.) Attempts were also 

 made to kill the organisms by the action of heat (Bastian, 

 Huizinga, &c.), or by the addition of a moderate amount 

 of carbolic acid (e.g., urine 0'5 per cent. Hoppe-Seyler). 

 Nevertheless putrefaction sometimes occurred. Finally, 

 attempts were made to remove the organisms from 

 putrefying or fermenting fluids by filtration ; but here, 

 also, putrefaction or fermentation of the fluid thus 

 filtered, and free from organisms, occurred in several 

 cases (Helmholtz 1843, Fleck, and others). 



In all these cases when the putrid fluids were ulti- 

 mately examined the observers found either no trace of 

 organisms, in which case the fermentation could only 

 have occurred under the influence of chemical ferments, 

 the existence and activity of which would lower the role 

 of the micro-organisms to a subordinate position ; or in 

 spite of all the precautions against the entrance of 

 organisms, they were found in the putrid substrata, and 

 then the supporters of abiogenesis saw therein a new 

 proof of the accuracy of their views. Even in quite 

 recent times Bechamp and Wigand have supported with 

 the greatest energy, and after many experiments, the 

 theory of the spontaneous generation of minute organ- 

 isms from the dying cell-protoplasm of higher organic 

 beings. They observed the origin of moving and 

 multiplying micro-organisms from the minutest consti- 

 tuents of dead animal and vegetable cells, and when all 

 external germs had apparently been completely excluded, 

 putrefaction and fermentation occurred under the influ- 

 ence of these organisms. 



Sources of In spite of the large number of observers and 



e"eriment8 S experiments, the germ theory is however not in any 

 way upset by these contradictory results. Sufficient 

 weight cannot be laid on the fact stated above, that in 

 these observations and experiments the results which 

 are unfavourable to the vitalistic theory always coincide 

 with possible errors of experimentation, or with want of 



