H. WORMALD 227 



A tube containing bouillon with 10 % alcohol was kept for over 

 two months after inoculation but no growth occurred. 



The organism then is capable of resisting 7 % alcohol and can 

 remain quiescent for some five weeks' during which period the percentage 

 of alcohol is gradually decreasing from 7 to about 2 (at 2 % as shown 

 above the period of retardation is almost reduced to zero). 



In those tubes where the development of the bacillus was markedly 

 retarded {i.e. 4 % and upwards) it was found, on subjecting drops of 

 the turbid liquid to microscopic examination^ that normal rods were 

 rarely if ever to be observed and they were represented by forms which 

 were almost isodiametric, thus resembling cocci ; rods approaching in 

 length the typical form were seen to be constricted in the middle as 

 in diplococci and obviously corresponded to two rods just before fission. 

 Reference to these coccus-like forms of the bacillus is made later in 

 this paper, but in the present connection it is to be remarked that when 

 first observed they suggested that perhaps contamination had occurred 

 during the preparation and inoculation of the tubes or, what was very 

 improbable, that the absolute alcohol employed contained resistant 

 spores which were stimulated to germination and propagation when 

 the alcohol was at a suitable low concentration. To test this point 

 six tubes of bouillon were prepared under aseptic conditions as before, 

 two containing 5 % alcohol, two with 2 % and two others with 1 %. 

 One of each pair was inoculated from a pure culture of the bacillus, 

 the others kept as control tubes. The inoculated tubes containing 

 2 % and 1 % alcohol respectively showed evidence of growth on the 

 following day, the former with a trace of turbidity, the latter distinctly 

 turbid, and later both produced a dense sediment of rods intermediate 

 in size between normal rods and the coccus forms. The inoculated 

 tube containing 5 % alcohol remained clear for eight days then became 

 turbid and eventually this also produced a dense sediment consisting 

 however of the coccus and diplococcus-like forms. The three uninocu- 

 lated tubes remained quite clear throughout the experiment, thus 

 proving that the organism present in the inoculated tubes was not an 

 extraneous one and confirming the conclusion that the precautions 

 taken in preparing the tubes ensured non-contamination. 



A Synthetic Solution as Culture Medium. 



For comparison with the results obtained with bouillon it was 

 thought desirable to start another series of experiments with antiseptics 

 using a medium of known composition. 



