ACTION OF ACIDS AND ALKALI Ks. 



eight-per-cent solution failed two hours' exposure. Exposure for 

 twenty-four hours to a ten-per-cent solution failed to kill the tubercle 

 bacillus (Schill and Fischer). A solution of one per cent kills the 

 anthrax bacillus, the bacillus of rothlauf, and several others (Jager). 

 The addition of 0. 14 per cent restrains the development of the typhoid 

 Iwcillus, and 0.18 per cent kills this bacillus in four or five hours; the 

 cholera spirillum failed to grow in cultures containing 0. 18 per cent 

 and was killed by 0.237 per cent in the same time (Kitasato). 



Sodium Hydroxide, NaHO. The experiments of Jager and of 

 Kitasato show that soda has about the same germicidal power as 

 caustic potash. Boer obtained the following results with bouillon 

 cultures after two hours' exposure: Anthrax bacillus, 1 : 450 ; diph- 

 theria bacillus, 1 : 300 ; glanders bacillus, 1 : 150 ; typhoid bacillus, 

 1 : 100 ; cholera spirillum, 1 : 150. In about one-half the amount 

 required to destroy vitality the development of the above-named bac- 

 teria was prevented. In the proportion of 1 : 56 it acts as an anti- 

 septic (Miquel). 



Ammonia, NH 3 . In Kitasato 's experiments the typhoid bacillus 

 wan destroyed in five hours by 0. 3 per cent of NH 3 , and the cholera 

 spirillum by about the same amount. Boer obtained the following 

 results, the time of exposure being two hours : Anthrax bacillus. 

 1 : :HX) : diphtheria bacillus, 1 : 250 ; glanders bacillus, 1 : 250 ; typhoid 

 I>acillu8, 1 : 200 ; cholera spirillum, 1 : 350. The growth of the an- 

 thrax bacillus and of the diphtheria bacillus in culture solutions was 

 prevented by 1 : 050. 



Calcium Hydroxide, Ca2HO. According to Kitasato, the ty- 

 phoid bacillus and the cholera spirillum, in bouillon cultures, are 

 killed in four or five hours by the addition of 0.1 per cent of calcium 

 \ i<te. Liborius had previously reported still more favorable results, 

 l>i it his bouillon cultures were largely diluted with distilled water. 



From a practical point of view the experiments of Pfuhl are more 

 valuable. Calcium hydrate was added to the dejections of typhoid 

 jwitieiits. When added in the proportion of three per cent steriliza- 

 tinii was effected in six hours, and by six per cent in two hours. 



When milk of lime containing twenty per cent of calcium hydrate 

 w;w used the results were still more favorable, the typhoid bacillus 

 and cholera spirillum being killed in one hour by the addition of 

 two per cent of the disinfectant. The practical value of lime- wash 



<I>H'"<1 to walls has been determined by Jager. Silk threads soaked 

 in cultures of various pathogenic bacteria were attached to boards 

 .u i.l th<> li mo-wash applied with a camel's-hair brush. Anthrax ba- 

 nlh (without spoivs), th<> glanders bacillus, Staphylococcus pyogene? 



nnvus. and several other pathogenic bacteria were killed by a single 

 application after twenty-four hours, but the tubercle bacillus was not 



