September 25, 1896.] 



SCIENCE. 



419 



the part concerned or other unusual cir- 

 cumstances, it is impossible to carry out 

 the antiseptic system completely. These, 

 however, are quite exceptional ; and even 

 in them much has been done to mitigate 

 the evil which cannot be altogether avoided. 



I ask your indulgence if I have seemed 

 to dwell too long upon matters in which I 

 have been personally concerned. I now 

 gladly return to the labors of others. 



The striking results of the application of 

 the germ theory to surgery acted as a 

 powerful stimulus to the investigation of 

 the nature of the micro-organisms con- 

 cerned; and it soon appeared that putrefac- 

 tion was by no means the only evil of mi- 

 crobic origin to which wounds were liable. 

 I had myself very early noticed that hos- 

 pital gangrene was not necessarily attended 

 by any unpleasant odor; and I afterwards 

 made a similar observation regarding the 

 matter formed in a remarkable epidemic of 

 erysipelas in Edinburgh obviously of infec- 

 tive character. I had also seen a careless 

 dressing followed by the occurrence of sup- 

 puration without putrefaction. And as 

 these non-putrefactive disorders had the 

 same self- propagating property as ferments, 

 and were suppressed by the same antiseptic 

 agencies which were used for combating 

 the putrefactive microbes, I did not doubt 

 that they were of an analogous origin ; and 

 I ventured to express the view that, just as 

 the various fermentations had each its 

 special microbe, so it might be with the 

 various complications of wounds. This 

 surmise was afterwards amply verified. 

 Prof. Ogston, of Aberdeen, was an early 

 worker in this field, and showed that in 

 acute abscesses, that is to say, those which 

 run a rapid course, the matter, although 

 often quite free from unpleasant odor, in- 

 variably contains micro-organisms belong- 

 ing to the group which, from the spherical 

 form of their elements, are termed micro- 

 cocci; and these he classed as streptococci 



or staphylococci, according as they were 

 arranged in chains or disposed in irregular 

 clusters like bunches of grapes. The German 

 pathologist, Fehleisen, followed with a beau- 

 tiful research, by which he clearly proved 

 that erysipelas is caused by a streptococcus. 

 A host of earnest workers in different 

 countries have cultivated the new science 

 of Bacteriology, and, while opening up a 

 wide fresh domain of Biology, have demon- 

 strated in so many cases the causal relation 

 between special micro-organisms and special 

 diseases, not only in wounds, but in the sys- 

 tem generally, as to afford ample confirma- 

 tion of the induction which had been made 

 by Pasteur that all infective disorders are 

 of microbic origin. 



JSTot that we can look forward with any- 

 thing like confidence to being able to see 

 the materies morhi of every disease of this 

 nature. One of the latest of such discov- 

 eries has been that by Pfeiflfer, of Berlin, of 

 the bacillus of influenza, perhaps the most 

 minute of all micro-organisms ever yet de- 

 tected. The bacillus of anthrax, the cause 

 of a plague common among cattle in some 

 parts of Europe, and often communicated 

 to sorters of foreign wool in this country, is 

 a giant as compared with this tiny being; 

 and supposing the microbe of any infectious 

 fever to be as much smaller than the influ- 

 enza bacillus as this is less than that of an- 

 thrax, a by no means unlikely hypothesis, 

 it is probable that it would never be visible 

 to man. The improvements of the micro- 

 scope, based on the principle established by 

 my father in the earlier part of the century, 

 have apparently nearly reached the limits 

 of what is possible. But that such para- 

 sites are really the causes of all this great 

 class of diseases can no longer be doubted. 



The first rational step towards the pre- 

 vention or cure of disease is to know its 

 cause; and it is impossible to over-estimate 

 the practical value of researches, such as 

 those to which I am now referring. Among 



