240 Profs. Percy Franklaud and Marshall Ward. 



Series II, in which the same water was employed, but a much 

 larger number of anthrax germs introduced (pp. 213 — 225). 



Series III, in which the water of Loch Katrine, taken as typical of 

 a moorland supply, was employed, and a large number of anthrax 

 germs introduced (pp. 225 — 239). 



2. In all these three series of experiments the waters were infected 

 with anthrax from an agar-agar cultivation of such age as to ensure 

 the abundant presence of spores, so that the investigation deals 

 exclusively with the vitality and virulence of sporiferous anthrax 

 bacilli (pp. 184, 213, 228). 



3. In the sterilised waters both of the Thames and Loch Katrine the 

 sporiferous anthrax bacilli maintain themselves in practically undi- 

 minished numbers for long periods of time — many months. In nearly 

 all cases, moreover, a distinct increase in the numbers was in the first 

 instance observed, which was followed in those cases in which the 

 experiments were extended over a sufficiently prolonged period by a 

 decline, which, however, in no case resulted in less than about one 

 half of the original number of anthrax spores being left in the water 

 after seven months. In the sterile Loch Katrine waters the anthrax 

 spores after upwards of three months were still two or three times 

 as numerous as in the first instance ; indeed, there was more dis- 

 tinct evidence of multiplication in the sterile Loch Katrine waters 

 than in either of the two series of Thames water experiments (pp. 

 200—204, 219—225, 232—235, 238, 239). 



As far as any difference could be established between the beha- 

 viour of the anthrax spores in these sterile waters at winter 

 (4 — 10° C.) and summer (18° 0.) temperatures respectively, the 

 balance of evidence was on the whole in favour of the numbers 

 being longer maintained at the low than at the high temperature, 

 although the preliminary increase took place more rapidly at the 

 high temperature and was earlier followed by the subsequent decline 

 (pp. 204, 224, 238). 



Practically no difference could be established between the beha- 

 viour of the anthrax germs in water sterilised by steam and by 

 filtration through porous 'porcelain respectively ; in the case of the 

 Loch Katrine water there was indeed some evidence of the steam- 

 sterilised water being more favourable to the anthrax spores than 

 that which had been filtered through porcelain (pp. 201 — 203, 

 220—223,232—234). 



No effect could be traced to the influence of diffused daylight on 

 the behaviour of the anthrax spores in these sterile waters, the 

 numbers in daylight and in darkness being practically the same 

 (pp. 204—206, 208, 221, 223, 233, 235). 



On the other hand, direct sunshine exerted a most marked effect, 



