PRACTICAL DIRECTIONS FOR DISINFECTION. 209 



meiit, but did not destroy their vitality in seven days; a three-per cent olu- 

 tion was effective in two days. According to Nocht, at a temperature of 

 37.50 C. anthrax spores are killed by a five-per-cent solution in three hours. 



Carbolic acid possesses the advantage of not being neutralized by the sub- 

 stances found in excreta, or by the presence of albumin. ThusBolton found 

 that the addition of ten per cent of dried albumin to a bouillon culture of 

 the typhoid bacillus did not materially influence the result, the bacillus be- 

 ing destroyed in two hours by a one-per-cent solution. 



This agent, then, is firmly established as a valuable disinfectant for ex- 

 creta, but we still give the preference to the standard solution of chloride 

 of lime of the Committee on Disinfectants for use in the sick-room, "on 

 account of the rapidity of its action, '' and also on account of its compara- 

 tive cheapness. 



At the International Sanitary Conference at Rome (1885) the writer, who 

 was associated with Dr. Koch on the Committee on Disinfectants, presented 

 the claims of chloride of lime, and in. the recommendations of the commit- 

 tee it was placed beside carbolic acid with the following directions : 



" Carbolic acid and chloride of lime are to be used in aqueous solution. 



"Weak solutions, carbolic acid, two per cent; chloride of lime, one per 

 cent. , 



"Strong solutions, carbolic acid, five per cent; < hloride of lime, four per 

 cent/' 



The strong solutions were to be used for the disinfection of excreta. 



Creolin, a coal-tar product, which is a syrupy, dark-brown fluid with the 

 odor of tar, has during the past three years received much attention from 

 the German bacteriologists. It is probably the same product which was 

 tested under the writer's direction for the Committee on Disinfectants, in 

 1885, under the name of "Little's soluble phenyle." It stood at the head 

 of the " Commercial Disinfectants " tested. The experiments made in Ger- 

 many show that it is not so active for spores as carbolic acid, but that it 

 very promptly kills known pathogenic bacteria, in the absence of spores, in 

 solutions of two per cent or less. Eisenberg found that a solution of two 

 per cent killed all test organisms within fifteen minutes. Esmarch found 

 it especially fatal to the cholera spirillum, which was killed by solutions of 

 1 : 1,000 in ten minutes. The typhoid bacillus showed much greater resist- 

 ing power a one-half-per-cent solution failed after ten minutes' exposure. 

 The pus cocci was still more resistant. Behring has shown that the pre- 

 sence of albumin greatly diminishes its germicidal power. As a deodorant 

 it is superior to carbolic acid, and on this account is to be preferred in the 

 sick-room. A recently prepared emulsion may be used to disinfect the liquid 

 excreta of cholera or typhoid patients, in the proportion of four per cent, 

 two hours' time being allowed for the action of the disinfectant. The ex- 

 periments of Jiiger upon pure cultures of the tubercle bacillus attached to 

 silk threads were successful in destroying the infecting power of these cul- 

 tures, as tested by inoculation into the anterior chamber of the eye of a 

 rabbit, when solutions of two per cent were used. 



The value of this agent as a disinfectant is then fully established; as to 

 its cost in comparison with the agents heretofore mentioned I am not in- 

 formed. 



Quicklime. Experiments made in Koch's laboratory in 1887 by Libo- 

 vius led him to place a high value upon recently burned quicklime as a dis- 

 infectant. More recent experiments by Jager, Kitasato, Pfuhl, and others 

 have shown that this agent has considerable germicidal power in the ab- 

 sence of spores, and that the value which has long been placed upon it for 

 the treatment of excrementitious material in latrines, etc., and as a wash for 

 exposed surfaces, is justified by the results of exact experiments made upon 

 known pathogenic bacteria. The germicidal power of lime is not interfered 

 with by the presence of albuminous material, but is neutralized by phos- 

 phates, carbonates, and other bases, and by carbonic acid. 



In the writer's experiments a saturated aqueous solution of calcium oxide 



14 



