yo Journal of Agricultural Research voi. iv, no. i 



Returning to conditions more closely resembling the Seymour-Jones 

 method, experiment 4 was carried out with a 24-hour exposure to the 

 disinfectant plus 10 per cent of defibrinated blood. The results are 

 given in Table II, experiment 4. 



The results of the preceding experiments indicated that in the presence 

 of 10 per cent of defibrinated blood anthrax spores are not destroyed in 

 2 hours by mercuric chlorid, i to 1,000, without formic acid, nor by 

 mercuric chlorid, i to 5,000, with i per cent of formic acid, but that they 

 are destroyed by mercuric chlorid, i to 2,000, with i per cent of formic 

 acid, under the same conditions. On the other hand, anthrax spores are 

 destroyed by mercuric chlorid, i to 1,000, without formic acid, and by 

 mercuric chlorid, i to 5,000, plus i per cent of formic acid, even in the 

 presence of defibrinated blood, when the time of exposure is 24 hours. 



On account of the greatly increased germicidal power of mercuric 

 chlorid in the presence of formic acid observed in the foregoing pre- 

 liminary experiments, it was deemed advisable to test the germicidal 

 power of mercuric chlorid and formic acid against anthrax spores dried 

 upon pieces of hide. The Bureau of Animal Industry (B. A. I.) strain 

 of Bacillus anthracis, which was employed in the previously described 

 "rod" method experiments, was used in infecting the pieces of hide. 



The results of these experiments, both by cultural methods and by 

 inoculation of animals, were entirely unsatisfactory, the reason for this 

 being apparently that the B. A. I. strain of Bacillus anthracis produced 

 spores of comparatively low virulence and low vitality. 



For this reason a culture of an entirely dififerent strain of Bacillus 

 anthracis was obtained from the Army Medical School (A. M. S.) through 

 the courtesy of Capt. Craig, and spores of this strain were used in all 

 further experiments. Experiments were made with "naked" spores 

 by the "rod" method and with spores dried upon pieces of hide. As the 

 subsequent records of these experiments will show, the spores of the 

 A. M. S. strain were found to be very much more virulent and resistant 

 to the action of disinfectants, drying, etc., than those of the B. A. I. 

 strain. 



n. EXPERIMENTS BY ROD METHOD, USING ARMY MEDICAL SCHOOL STRAIN OF BACILLUS 



ANTHRACIS 



The technique of these experiments was exactly the same as for those 

 with the B. A. I. strain, except that the quantity of disinfectant per rod 

 was made 10 c. c. instead of 5 c. c. 



Experiment 5 (Table III) indicates that mercuric chlorid, i to 4,000, 

 plus I per cent of formic acid, is able to destroy anthrax spores of the 

 A. M. S. strain in 24 hours when no organic matter is added. 



