MICRO-ORGANISMS AS EXCITING AGENTS OF DISEASE. 95 



from them the corresponding mould, and could in this 

 way demonstrate the true cause of the disease. By the 

 investigation of and cultivation from a great variety of 

 diseased organs and excreta Hallier obtained a series of 

 different fungi which he proclaimed to be the causes of 

 the diseases ; and in a short time scarlet fever, measles, 

 as well as cholera, typhoid fever, and all other diseases 

 of this class, were referred to their supposed cause. 



The reaction to this period of fantastical exaggeration Reaction 

 was inevitable. Authorities on fungi like de Bary yf<?^! 

 showed that Hallier's investigations were quite value- 

 less, because they were conducted with totally insufficient 

 precautions against the entrance of extraneous organ- 

 isms. De Bary's objections could not be upset, the 

 structure of Hallier's teaching on parasitic diseases fell, 

 and at the same time a serious blow was given to the 

 whole parasitic theory ; even up to the present day 

 there are those who, as the result of the overthrow of 

 these errors, look on the development of disease by 

 micro-organisms as an erroneous and exploded view. 



Further positive discoveries with regard to parasites 

 which have been made by numerous investigators in 

 recent years tended, however, to restore the lost faith. 

 These discoveries had chiefly reference to the infective Micro- 

 diseases of wounds ; Rindfleisch, Waldeyer, and von fn 

 Recklinghausen (1866, 1870) were the first who directed 

 attention to the micro-organisms which occurred in 

 pyaemic processes ; similar Observations were made in 

 erysipelas, in phlegmon, in diphtheria, and in puerperal 

 fever (Hiiter, Orth, Oerftel, and others). The pathogenic 

 nature of the micro-organisms found was confirmed by 

 numerous experiments on animals (Coze and Feltz, 

 Davaine, Hiiter, Eberth, Leber, Frisch, Klebs, and 

 others) . 



The striking results of Lister's antiseptic treatment of Lister's 

 wounds had a most important influence on the recogni- treatment of 

 tion of the parasitic theory ; carried out with the definite wounds - 

 aim of preventing or hindering the action of the infective 

 organisms, and followed by astonishing results, it spread 

 widely the knowledge and importance of the micro- 



