KOCH, ROBERT. 



475 



conveying infection lasted only for a few weeks; 

 while blood in which the spores had .separated 

 continued virulent for four years. Living organ- 

 isms had been observed in those infectious dis- 

 orders which originate in the introduction of 

 poisonous matter through wounds, but their con- 

 nection with the development of the infection 



ROBERT KOCH. 



had not been determined. Dr. Koch's experi- 

 ments with small animals showed that different 

 forms of disease were produced by the injection 

 of putrid blood, one of which was not accom- 

 panied by the development of bacteria, but 

 seemed due to a special poison which he named 

 septin or sepsin, while another form was evi- 

 dently bacterial ; and that the effects varied with 

 different animals. 



In 1882 he published the results of experi- 

 ments that went to confirm the opinion that 

 tubercular disease was also caused by micro- 

 phytic germs. He claimed not only to have ascer- 

 tained the bacterial origin of the disease, but to 

 have detected the specific microbe, having found 

 a characteristic and previously unknown bacillus 

 in all tubercularly altered organs. He had ob- 

 served it in pulmonary tuberculosis, cheesy bron- 

 chitis and pneumonia, tubercles of the brain, in- 

 testinal tubercles, scrofulous glands, and fun- 

 gous inflammation of the joints ; in all cases 

 which he had examined of spontaneous con- 

 sumption in animals in cattle, hogs, poultry, 

 monkeys, porpoises, and rabbits. In monkeys 

 dead of consumption he had found the organ- 

 isms in quantities prevailing the lungs, spleen, 

 liver, diaphragm, and lymphatic glands. 



His report of this investigation was published 

 in a Berlin medical journal, in a memoir on 

 "The Etiology of Tuberculosis," of which Dr. 

 Klein, a distinguished pathologist, said that any 

 one who carefully reviewed it would "come to 

 the conclusion that Dr. Koch's results are to be 

 accepted with tinconditional faith." Dr. Klein 

 afterward disputed Koch's indentification of the 

 " comma bacillus " with the cause of cholera. 

 In the next year a report was published by Wat- 

 son Cheyne of a visit that he had made as a 

 commissioner of the British Association for the 

 Advancement of Medicine by Research, to the 

 laboratory of Dr. Koch, and* also to that of M. 

 Toussaint, who was engaged in a similar investi- 



gation. It represented that such results of 

 Toussaint as disagreed with those obtained by 

 Dr. Koch were not borne out. But the result 

 of inoculation with cultivations obtained from 

 Dr. Koch was in all cases rapid development of 

 tuberculosis. The examination of a large quan- 

 tity of tuberculous material showed the constant 

 presence of tubercle bacilli, but of no other 

 micro-organisms. The rapidity and certainty of 

 action of this matter, when inoculated into ani- 

 mals, was in direct ratio to the number of ba- 

 cilli introduced, and the most certain and rapid 

 means of inducing tuberculosis seemed to be 

 tlje inoculation of the tubercle bacillus cultivated 

 on solid blood-serum. 



When cholera broke out in Egypt in 1883, the 

 German Government appointed 'Dr. Koch chief 

 of a commission to go to that country, and to 

 India, for the purpose of investigating the nature 

 and cause of the disease. The report of the work 

 of this commission in Egypt pointed out the line 

 on which future studies were to be pursued. In 

 experiments carried on in both living and dead 

 subjects, while no distinct organism could be 

 traced in the blood and the organs that are most 

 frequently the seat of micro-parasites, bacteria 

 having distinct characteristics were found in the 

 intestines and their mucous linings, under cir- 

 cumstances that seemed to identify them with the 

 disease from which the patients were suffering. 

 They were present in the case of all patients suf- 

 fering from cholera, and in the bodies of all who 

 had died of it, whereas they were absent in the 

 case of one patient who had had time to recover 

 from cholera, but had died of some secondary 

 complication; and they were not discoverable in 

 the case of patients who, during the cholera epi- 

 demic, succumbed to other diseases. They were 

 also the same with the bacillus that Dr. Koch 

 had met the year before in the bodies of patients 

 who had died of cholera in India. In 1884 Dr. 

 Koch visited Toulon, where cholera was raging. 

 The investigations of the German commission 

 were continued in India, and his report on the 

 subject was published in the " Klinische Woch- 

 enschrift " of Berlin, No. xxxiv, 1884. He had 

 found, in the rice-water discharges of patients 

 suffering from cholera, peculiar curved bacteria, 

 which have become known as "comma-shaped" 

 bacilli, such as he had not been able to discover 

 in any cases of diarrhoea ; and he had succeeded 

 in isolating them by artificial culture. This he 

 declared to be a specific micro-organism having 

 marked characteristics distinguishing it from all 

 other known organisms. These organisms grow 

 rapidly in meat-infusion and blood-serum, and 

 well in other fluids, especially milk, and in 

 potatoes ; and possess the power of active motion. 

 They are not killed by freezing. They grow only 

 in the presence of oxygen, and very fast ; their 

 vegetation rapidly reaches its highest point, then 

 remains stationary for a time, after which it 

 ceases as rapidly as it grew, and the bacilli die. 

 When dried, they die within three hours; and 

 they do not form* spores. Micro-organisms pos- 

 sessing all of these and certain more delicate 

 characteristics which are definitely described are 

 Koch's bacilli. 



The presence of these bacilli in cholera was 

 determined by microscopical examination in ten 

 cases in Egypt, and by microscopical examination 



