882 



SCIENCE 



[N. S. Vol. XLI. No. 1068 



in the upper realms of imagination saw the 

 "germs" or "microbes" and firmly be- 

 lieved them to be the cause of infection. 

 In 1900, at the age of seventy-three, Lister 

 restated his earlier work= and illuminated 

 it by many observations, experiments and 

 drawings made in these early years, but 

 first published fifty years after they were 

 made. 



If you wish to know the man, his fertil- 

 ity in devising new and convincing experi- 

 ments, and his mental acumen in inter- 

 preting them "read, mark, learn and in- 

 wardly digest" that paper and use it as a 

 model. 



Pare in his na'ive way tells us that he 

 sought various applications which might 

 "mitigate the pains [of his patients] and 

 happily" — mark the word "happily" — 

 ' ' bring them to suppuration. ' ' That is the 

 "laudable pus" of the pre-Listerian days. 

 Lister, on the contrary, believing that in- 

 fection and suppuration were evils, and 

 avoidable evils, sought by various means to 

 prevent them. But he says ' ' all my efforts 

 [during his work in Glasgow, 1860-69] 

 proved abortive," and then adds signif- 

 icantly " as I could hardly wonder when I 

 believed with chemists generally that putre- 

 faction was caused by the oxygen of the 

 air. ' ' 



They and he were deeply impressed with 

 the absence of putrefaction in simple frac- 

 tures when the air and its oxygen had no 

 access to the fracture. In my own lectures, 

 as I often used to express it, ' ' The very best 

 antiseptic dressing is an unbroken skin." 

 In compound fractures on the other hand 

 when the air and its oxygen Jiad access to 

 the lesion, putrefaction always took place 

 an,d caused a frightful mortality. 



To test this supposed noxious influence 

 of oxygen he devised many experiments, and 

 among them one which may be well called 

 2 Brit. 'Med. Jour., 1900, II., 969. 



an ' ' experimentum crucis. ' ' He filled four 

 flasks one third full of urine (a quickly 

 putrescible liquid) and drew out the 

 necks to tubes one twelfth of an inch in 

 diameter. All these tubes were left open. 

 Three of these long necks he bent at vari- 

 ous angles downwards ; the fourth was left 

 vertical upwards and also open. He then 

 boiled all four flasks and awaited the re- 

 sult. The air and its oxygen had free ac- 

 cess to the urine, being slowly drawn in 

 during the colder night hours and driven 

 out in the warmer daytime. Any supposed 

 "germs" floating in the air, he reasoned, 

 being heavier than air, could not climb up 

 the slanting necks and fall into the liquid. 

 In a short time the urine in the flask with 

 the vertical open neck was decomposed, but 

 the other three flasks, also with open necks 

 biit bent downward, remained undecom- 

 posed for four years !^ 



Could there be a more convincing proof 

 that the oxygen had no influence whatever 

 in producing putrefaction, but that it was 

 due to living matter, "germs," in the air? 

 It was a fine instance of the "scientific use 

 of the imagination." "Germs" had been 

 observed from time to time, but had not 

 been generally accepted as the vera causa 

 of putrefaction. The experiment just re- 

 lated was tried about 1867. The common- 

 est, all-pervading germs, the staphylococcus 

 and streptococcus, were not identified and 

 proved to be the chief pyogenic (pus- 

 producing) organisms until 1881, fourteen 

 years after Lister had seen them so clearly 

 with his mind 's eye ! Even in 1898 when I 

 published my ' ' Surgical Complications and 

 Sequels of Typhoid Fever" I had to prove 

 by elaborate citations of experimental and 

 clinical evidence that the typhoid bacillus 

 itself could cause suppuration, and that it 



3 For a fuller account of this interesting ex- 

 periment with references see my ' ' Animal Ex- 

 perimentation and Medical Progress, ' ' pp. 204- 

 205. 



