224 Profs. Percy Frankland and Marshall Ward. 



unfiltered water. This greater impregnation of the unfiltered water 

 was intentionally effected so as to heighten the contrast which it was 

 anticipated would be presented at the close of the experiments. Thus 

 on June 16, 1892, or 83 days from infection, the sterile waters still 

 yielded several thousand anthrax colonies per cubic centimetre, whilst 

 in the unfiltered water on the following day (June 17, 1892) only 

 1200 anthrax colonies could at most be detected. Or, again, com- 

 paring the results obtained by the special method of preliminary 

 heating, on June 17, 1892, the unfiltered water yielded a maximum of 

 49 colonies per cubic centimetre ; whilst on July 11, 1892, or nearly 

 a month later, the porcelain-filtered water yielded by the same 

 method 128 — 145 colonies per cubic centimetre, and the steamed 

 water on the same day (July 11, 1892), 163 — 179 colonies per cubic 

 centimetre. 



There is thus again the most convincing proof that the degenera- 

 tion of the spores of anthrax is more rapid in the unsterilised than 

 in the sterilised water, whilst it is almost immaterial in this respect 

 whether the latter is sterilised by steam or by filtration through 

 porous porcelain, although there is some slight evidence that the 

 steam-sterilised water is more favourable to the preservation of the 

 anthrax germs than that which has been rendered sterile by filtration 

 through porcelain. 



As regards the influence of temperature on the preservation of 

 anthrax, in the First Series of experiments the evidence apparently 

 pointed in the direction of the degeneration taking place more 

 rapidly at the summer than at the winter temperature ; whilst in the 

 Second Series of experiments the indications are uncertain, and I am 

 of opinion, therefore, that the difference of temperature in question 

 is probably a matter of little consequence in this respect. 



Finally examining the results obtained in the last plate cultiva- 

 tions made in October, it will be seen that the anthrax germs were 

 still present in the sterile waters (steamed and porcelain-filtered) in 

 practically undiminished numbers, whilst in the unsterilised water 

 their numbers were so much reduced that they could only just be 

 still recognised by the special method of preliminary heating. 



I made the following experiments in order to test the virulence of 

 these infected sterile waters of the Second Series : — 



Animal Experiment No. 6 — On October 12, 1892, 1 c.c. of water 

 from the flask " 1 1, Thames water, steam-sterilised (Second Series), 

 infected with anthrax on March 25, 1892," was subcutaneously in- 

 jected into a white mouse. The mouse died within 2 days 21 hours ; 

 the body exhibited much oedema ; the spleen was very much enlarged, 

 and anthrax bacilli were fairly abundant in it, the gelatine cultures 

 also developing the characteristic growths in due course. 



