6o 



NATURE 



[NOVEMUER 2 I, 1907 



agents throug'h which the disease is transmitted to 

 man. " Kolle and Nuttall, however, obtained negative 

 results in this direction. The Indian Plague Com- 

 mission (i8gq) came to the conclusion that Siniond's 

 proposition that suctorial insects play an important 

 part in the transmission of plague from sick 10 

 healthy animals is so weak as to be hardly deserving 

 of consideration. 



In i()02 Gauthier and Raybaud, at Marseilles, car- 

 ried out further experiments, and got positive results. 



" Recueillant en bloc un certain nombre de puces 

 sur des rats captures sains, nous avons parasite arti- 

 ficiellement h leur asile des animaux de laboratoire 

 pr(5alablement inocuMs de cultures pures. Nous 

 avons cherchd ensuite h produire infestation parasi- 

 taire et I'infection consecutive d'animau.x neufs. Les 

 resultats absolumpnt concordnnts de cette serie d'e.x- 

 periences (five experiments) nous permettent de con- 

 clure que les puces des rats sont capables d'une facjon 

 constante de transmettre la peste d'animal h. animal 

 rat ou souris." 



Further, they showed that rat fleas could bite man. 



Ashburton Thompson, studying the plague epi- 

 demics in Sydney from the epidemiological stand- 

 point, came to the conclusion that Simond's hvpo- 

 thesis of the flea best explains the phenomena of the 

 epidemic plague as seen at Sydney. He further states 

 that the laboratory proof has been given by Raybaud 

 and Gauthier, and bv Dr. J. S. C. Elkington at 

 Bombav, " whose observations are affirmatory of 

 Simond's original experiments made in India." 



Elkington ' describes his own results in the follow- 

 ing words : — " The technical difficulties were con- 

 siderable . . . and a great deal of experiment was 

 required before a satisfactory means was obtained 

 of insuring the captivity of such a small and active 

 insect whilst feeding. This was finally effected bv 

 confining them in a test tube of which the mouth 

 was covered with very fine gauze through which 

 the insect could thrust its proboscis when the gauze 

 was applied to the skin of the feeder-animal. Fleas 

 were then fed on experimentallv infected rats. 

 . . . The fleas were then kept in a dark drawer 

 still in the feeding tube for varyine periods, after 

 which they were again fed on healthv young rats 

 selected for their vigour and health. The re- 

 sults were most successful, and I have re- 

 cords of four instances in which I was able to 

 carry out this method of infection. Captain Listen 

 also was successful in several cases. Attempts were 

 then made to convey the disease from human beings 

 to rats. Two instances were successful, the period 

 from the first feeding being eight hours. . . . Both 

 rats died of plague, one on the fourth, the other on 

 the sixth day." 



Much attention was now given to the question as 

 to what species of fleas those found on rats belong. 



Tidswell, in 1^03, working at Svdnev, found that 

 Si per cent, of the fleas on rats were P. pallidus (i.e. 

 P. cheopis). Tiraboschi found that 40 per cent, of 

 fleas on ship rats belonged to the same species. 

 Liston, 1005, found that while other species were 

 found on European rats in India, qq per cent, of the 

 fleas were P. cheopis. Though unable himself to 

 get positive results in the transmission, yet he says, 

 " To sum up, then, rat fleas (P. cheopis) can alwavs 

 be found in (plague) Infected houses; these fleas will 

 take to an animal which is not their normal host." 

 Finally we have the experiments of the Plague Com- 

 mission of iqo:; working in Bombay. These elabor- 

 ate and very carefully conducted experiments have 



1 Board of Publir Health. Address on Fleas snd PUgiie Corvecllon 

 hv T)r. I. S. C. Elkington, delivered before the Victorian Branch of the 

 British Medical Association, July 22, 1903. 



NO. 1986, VOL. yy] 



conclusively established the fact of the conveyance 

 of plague from the infected to the healthy rat by 

 means of the plague flea. We still require light on 

 the exact method by which the bacilli are conveyed ; 

 why so many other investigators have failed in 

 similar experiments, and whether rats transmit the 

 di.sea.se in any other way, and, indeed, whether this 

 is the most important way. In discoveries of this 

 kind we are apt to give the credit at the time to the 

 person who forges the last link of the chain which 

 stretches across the gap of unknown causes. Credit 

 is. however, also due to those who forge the inter- 

 mediate links ; indeed, perhaps most of all to him 

 who forged the first link, without which the chain 

 would not have been begun. 



J. W. W. S. 

 Literature. 



Consult especially : — 



Abel : Zeit. f. Hygiene. Heft, xxxvi., iqoi. 



Tiraboschi : Zeit. f. Hygiene, Heft, xlviii., 1904. 



Journal of Hygiene, vol. vi., No. 4, September, 

 igo6. 



Loir: " Histolre des Epidemie de Peste h Tunis." 

 Kev. Scientif., iqoo. No. 13, p. 395. 



.Allbutt and Rolleston : " System of Medicine," vol. 

 ii., part ii., p. 375, .Art. "Plague." 



Gauthier et Raybaud : Revue d'Hygiene, 1903. 



.Ashburton Thompson : Report on the Outbreak of 

 Plague at .Svdney, dated Julv, 1903. 



T. S. C. Elkington : Australasian Medical Gazette, 

 xxii., p. 348. 



THE INTERN ATWN.AL ASSOCIATION OF 

 SEISMOLOGY. 

 'X'HE first general meeting of the International 

 ' Association of Seismology was held at The 

 Hague on September 24 and 25, and was preceded 

 on September 21 and 23 by a meeting of the per- 

 manent committee, which is the body charged with 

 carrying out the decisions of the general assembly. 



The following countries (in alphabetic.il order 

 according to their French names) now form part of the 

 association : — Germany, -Austria, Belgium, Bulgaria, 

 Canada, Chili, Congo, Spain, United States, Great 

 Britain, Greece, Hungary, Japan, Italy, Mexico, Nor- 

 way, the Colonies of the Netherlands, Portugal, 

 Roumania, Russia, Servia, and Switzerland. It was 

 understood that the French Government was pre- 

 pared to join, but as the necessary money grant had 

 not been submitted to the Chamber of Deputies, the 

 adhesion has not yet been formally made. Neverthe- 

 less, the French delegates were requested to take part 

 in the proceedings on the same footing as those of 

 the other countries. 



The budget for the forthcoming year was submitted 

 to the permanent committee, and was carefully dis- 

 cussed. The income of the association is now about 

 1900Z. The secretary. Prof. Kovesligethy, of Buda- 

 pest, on whom a great part of the labour of the asso- 

 ciation falls, receives 200?. ; 460Z. is spent in other 

 salaries, including those of a type-writer, mechanic, 

 and in connection with the Centra! Bureau at Strass- 

 burg; oflice expenses amount to about 150/. 



In addition to the above salaries, two scientific 

 assistants, l\fr. Rosenthal, of Pulkowa, and Mr. 

 Oddone, of Rome, were during last year paid out of 

 the funds of the association, and were engaged in 

 preparing separate catalogues of microseismic and 

 macro.seismic disturbances. The question how far 

 scientific assistants of this kind should during the 

 next two years be maintained by the association was 

 left to the decision of the executive committee, which 



