150 THE IDENTITY OF BACTERIUM FCETIDUM WITH SOIL COCCI. 



spores being in all respects identical with the cocci found upon 

 the feet. 



While examining the coccus form of Bacterium fostidum and the 

 cocci of surface soil ( " corpuscules brillants" of Pasteur), I was 

 struck by the great similarity between them, and determined to 

 ascertain wliether the identity were real or merely apparent. That 

 there is a real identity the following experiments tend to show. 



Morpholotjical proof of the idenlity of Bacterium foetiduin Thin tvith 



soil- cocci. 



The method adopted was to cultivate, in imitation of Dr. Thin, 

 ferment from soil lying immediately beneath the surface, and the 

 Bacterium (obtained by scraping fetid socks after a short soaking 

 in distilled water), in test-glasses containing vitreous humour. As 

 in Dr. Thin's experiments, the test-glasses, provided with glass 

 caps and covered by a larger glass, were purified by exposure to a 

 temperature above 300° Fahr. for two hours ; the vitreous humour, 

 forced through fine muslin, was sterilised by introducing it with 

 care into carbolised cotton-wool plugged test-tubes previously puri- 

 fied similarly to the glasses, and then kept in boiling water for 

 half an hour. The soil, freed as far as possible from traces of 

 organic matter, was sifted through fine muslin before being placed 

 in a test-glass.* Dr. Thin satisfied himself that his fluids were 

 sterilised by the above treatment, and one of my fluids examined 

 after a fortnight showed no trace of organisms. I, however, made 

 some additional experiments, with the same results as were ob- 

 tained with fluids treated according to Thin's method — with fluids 

 sterilised in test tubes provided with firmly secured corks previously 

 soaked in creosote and turpentine, and kept in boiling water for 

 several hours on three successive days. A test-fluid so treated 

 remained clear for upwards of two months, and showed no trace of 

 organisms when examined. 



After cultivating for two or three days in a warm chamber kept, 

 by means of a Page's apparatus, at 9G°-99° Fahr., the surface of 

 the liquid in Avhich the Bacterium fcetidiim. was growing, as well as 

 of that charged with soil, was covered with a firm resistant scum. 

 In the scum of the latter, and in the liquid below it, were found 

 the series of forms now to be described. 



At the first stage bright cocci are seen contained each in a 

 darker wedge- or canoe-shaped envelope; their position in the canoe 

 is almost always a little to one side of the centre, in the wedge 

 at the wider end. The wedge or canoe may end either sharply or 

 bluntly. Sometimes two cocci are found in association in a double 

 semicanoe-shaped envelope, similar to those shown at fig. 3^ of Dr. 

 Thin's memoir ; but two cocci, oscillating within a single canoe (seen 



* The vitreous humour, the soil and the Bacterium were introduced into 

 the purified test-glasses, uncovered, when held iar hack over an open fire and as 

 near to the fire as possible. 'Vhe test-tubes were similarly opened to receive the 

 vitreous humour. This method I consider as good as, perhaps preferable to, 

 the carbolic-spray method. The cotton-wool plugs were about IJ inch in length. 



