eventually become permanent ceased reactors, we can at one or other of these 

 stages make reasonably certain of those which will not do so. 



Animals which, on being first tested, show a thermal rise exceeding 104° 

 Fahreriheit, accompanied by a characteristic -reactioTi, those whicih ^ve a more 

 pronounced reaction to a second or subsequent test than they do to the firsts 

 and those which suddenly cease to react without showing a gradual lowering 

 of the temperature and a corresponding abatement of the local reaction are not 

 likely to become permanent ceased reactors. 



Sound pathological reasons can, I think, be advanced for the lack of im- 

 provement shoWn by the first and second classes, but I must confess that I have 

 no mental theory to fit the case of those last mentioned. . . 



Having now dealt with the supposititious ceased reactors and with, those 

 which appear to make an actual and permanent recovery, it becomes, our duty 

 to discuss those animals, and they are, in our experience, by, far the most 

 freqiuently encountered, and, needless to say, the most dangerous, •whioh- 

 acquire a temporary tolerance to Mallein, but which again give a definite - 

 reaction when tested, after sufficient time has.elapsed to .nullify the^ffects of ' 

 p-evious injections. In the report ;0f the Special Committee appointed by the 

 British Board of Agriculture, to which I have already referred, the records- / 

 'given indicate that all the ceased reactors dealt with in the experiments showed'.' 

 an abnormally high temperature when tested with Mallein some- time after 

 they had apparently ceased to react. I considered this a very suspicious- 

 circumstance, and one which furnished food for serious thougfht. In order, to- 

 discover, if possible, the reason of this peculiar phenomenon I determined to- 

 again submit to the Mallein test a number of .horses which had been" kept for 

 varying periods tinder supervision' as ceased' reactors, 'f he results- were very- • 

 interesting, as may be gathered from the following examples from the report 

 ot Dr. A. E. Moore, one of our most careful and capable officers, who was- 

 ■ entrusted with the .task of conducting the investigatio.ns. The pathologicaK ■ 

 work was, of course, done by Dr. Higgjns. ' - 



Results of post mortem examinations conducted on ceased reactors whicln'v^ 

 again reacted on being tested, after a period of-not less than six months : 



PEddy, Grey Gelding, 16 Years, No. 304. 



Max. temp. Max. temp. Max. size 



before inject, after inject, swelling " 



I St test, May 22, 1903 1004-5 ' 105 6x6 



2nd test, June 7, 1903 ... ; 1002-5 1052-5 4x5 



3rd test, Sept.,7, 1903 : 100 2-5 ioi 2-5 2x3 ceasecfi: 



4th test, Oct. 25, 1903 IOI IOI ,x4 '■ 



Retest after i year and 2 months, Dec, - ■' 



^^■^'^ IOI 2-5 104 ,x6 



Result of post mortem of No. 304 : ' ' 



Very few nodules scattered in the lungs, .around some of these nodules a- 

 small quantity of lymph-like substance was seen, others encysted 



■.« 



