12 . REVIEW — TROPICAL MEDICINE, ETC. 



Bacteriology sources. Tiillat, quoted by Arnold, regards the action as duu to the presence of formaldehyde 

 —continued j^ tobacco sinoke. The kind of tobacco employed seemed to exert no influence on the results. 



Castellani' has isolated from the blood of three patients suffering from fever, in Ceylon, an 

 organism which he has called Bacillus ceijhmensis. Further particulars will be found under 

 the heading of " Fever " {paye 69), but it may be stated here that the bacillus was non-motile, 

 produced a pellicle in broth, acidified and coagulated milk slowly, produced acid but no gas 

 in glucose, and produced neither acid nor gas in saccharose, manuite, dulcite or lactose. 

 There was no indol formation. From a fourth case, in which the clinical symptoms were 

 slightly different, a somewhat similar organism was isolated, but it acidified and clotted milk 

 quickly and formed indol. In every instance the organisms were agglutinated by the blood of 

 the patients from whom they were recovered. 



When examining a well-water in Khartoum, I came across an organism which morpho- 

 logically and culturally resembled this B. ceylanensis, but the only sugar media in which it 

 was tested were lactose and glucose and its pathogenicity was not determined. Intra- 

 peritoneal injections of broth cultures of B. ceylanensis killed guinea pigs in 24 to 36 hours. 



Buckley,^ in a very important paper, records the results of his careful and elaborate 

 experiments on the resistance of some pathogenetic micro-organisms to drying. Those 

 used were Staphylococcus pyogenes aureus. Bacillus coli communis, Bacillus typhosus, Bacillus 

 diphtherias, Bacillus pestis and Spirillum choleras. Of these, Staphylococcus pyogenes aureus 

 was found to be the most, and Spirillum choleras the least, resistant. 



The latter cannot live in a condition of complete dryness. Of the other four, B. coli 

 commimis and B. typhosus proved more resistant than the B. diphtheriee and B. pestis. The 

 remaining conclusions I quote verbatim : — 



Some organisms live longer in a moist and others in a dry atmosphere. In the first class are the 

 Spirillum, chnh'rw and the Bacillus coli communis, which live very much longer, and the Bacillus typhosus 

 and the Bacillus pestis, which live only slightly longer, in a moist atmosphere than in a dry one. In the 

 second class are the Staphylococcus pyogenes aureus and the Bacillus diphtheriee. 



Speaking generally, the absolutely dry atmosphere of the desiccator is less harmful to the bacteria used 

 in these experiments than the partially dry atmosphere of the room. This is possibly due, as suggested by 

 some observers, to the quick drying of the outer portions of the individual bacilli, which would result in the 

 formation of a complete protective coat for each organism. The cholera spirillum is an exception to this rule. 



The material infected exerts a considerable influence on the powers of resistance to drying possessed by 

 the different organisms ; but this influence is not of the same kind on all bacteria nor under all conditions of 

 dryness or moisture. On examining the Tables it will be found that the longest life was reached usually on 

 plaster and Ume wood. The single exception is in the case of the Bacillus pestis, which was very short- 

 lived on lime wood, and this was the case in each of ten series of experiments. All the organisms were 

 short-lived on paper. As would be expected from the fact that the emulsion is unable to sink into glass, and 

 would consequently dry rapidly, the organisms did not live very long on that material. 



The effect of pine wood was variable, and especially so in the moist chamber, pointing to the fact that 

 some constituent or constituents of the wood were capable of acting injuriously upon the organisms in the 

 presence of moisture. In all cases this variety of wood exercised an adverse influence on the organisms, and 

 this suggests the advisability, from a sanitary standpoint, of the use of pine wood, as far as possible, in such 

 buildings as hospitals — and especially hospitals for infectious diseases. 



Infection can persist in dry buildings, cloths, etc., for at least the following periods: — 



Staphylococcus pyogenes aureus ... 

 Bacillus diphtheria: ... 

 Bacillus coli communis 

 Bacillus typhosus 



Bacillus pestis ... 



Spirillum cholcrm ... ... 



(These figures represent in each case the longest period during which the organism was found living on 

 any material in the desiccator, or in the air of the room). 



In the case of certain organisms, infection may persist for even longer periods if the buildings, etc., 

 are damp : — 



Bacillus coli communis for 168 days. 



Bacillus typhosus ... ... ... ... ... ... ... ,, 119 ,, 



Bacillus pestis ... ... ... ... ... ... ... „ 45 ,, 



Spirillum cholerce ... „ 21 „ 



' Castellani, A. (January, 1907) , " Notes on cases of Fever frequently confounded with Typhoid and Malaria 

 in the Tropics." Journal of Hygiene, p. 1, Vol. VII. 



^ Buckley, Q. Q. (February, 1907), " The Resistance of some Pathogenic Micro-organisms to Drying." Public 

 Health, p. 290. 



