300 FRAGMENTS OF SCIENCE. 



throw abundant light upon their author, but no shade 

 upon Pasteur. 



Redi, as we have seen, proved the maggots of putre- 

 fying flesh to be derived from the eggs of flies ; Schwann 

 proved putrefaction itself to be the concomitant of 

 far lower forms of life than those dealt with by Eedi. 

 Our knowledge here, as elsewhere in connection with 

 this subject, has been vastly extended by Professor 

 Cohn, of Breslau. ' No putrefaction,' he says, ' can occur 

 in a nitrogenous substance if its bacteria be destroyed 

 and new ones prevented from entering it. Putrefaction 

 begins as soon as bacteria, even in the smallest numbers, 

 are admitted either accidentally or purposely. It 

 progresses in direct proportion to the multiplication 

 of the bacteria, it is retarded when they exhibit low 

 vitality, and is stopped by all influences which either 

 hinder their development or kill them. All bactericidal 

 media are therefore antiseptic and disinfecting.' 1 It 

 was these organisms acting in wound and abscess which 

 so frequently converted our hospitals into charnel- 

 houses, and it is their destruction by the antiseptic 

 system that now renders justifiable operations which no 

 surgeon would have attempted a few years ago. The 

 gain is immense to the practising surgeon as well as 

 to the patient practised upon. Contrast the anxiety of 

 never feeling sure whether the most brilliant operation 

 might not be rendered nugatory by the access of a few 

 particles of unseen hospital dust, with the comfort 

 derived from the knowledge that all power of mischief 

 on the part of such dust has been surely and certainly 



1 In his last excellent memoir Cohn expresses himself thus: 

 *Wernoch heut die Faulniss von einer spontanen Dissociation der 

 Proteinmolecule, oder von einem unorganisirten Ferment ableitet, 

 oder gar aus " Stickstoffsplittern " die Balken zur Stiitze seiner 

 Faulmsstheorie zu zimmern versucht, hat zuerst den Satz " keine 

 Faulniss ohne Bacterium Termo " zu widerlegen.' 



