Pests. 



264 



[March, 1909. 



other methods ; but to distinguish 

 between the various members of these 

 groups presents very considerable diffi- 

 culty, and entails laborious and tediou 

 serological operations. 



Not having yet had the opportunity 

 of perusing Professor Klein's report, nor 

 the detailed account of his experimental 

 work, I can only relate here those 

 results which I have obtained from a 

 very long and extensive experience with 

 the Liverpool virus as have any bearing 

 on the question of disease in the human 

 subject produced directly or indirectly 

 through the injection of this organism. 

 I ought, however, first to mention that I 

 have recently become aware of records 

 of cases of meat poisoning in man by 

 the use of cultures of the B. typhi 

 murium (Loeffler), which have been " put 

 down ' for rats and mice in Japan and 

 other countries. 



I have records of cases in which the 

 rat virus has been more or less deli- 

 berately injected by adults and by 

 children without the slightest deleterious 

 effects; and in the six years during which 

 the virus has been sold for the des- 

 truction of the vermin, in very large 

 quantities (some 10,000 tubes per annum), 

 and must have been handled on very 

 frequent occasions in such a way as to 

 be inadvertently and directly introduced 

 into the mouth, I have received records 

 of only two eases in which the virus 

 was suspected of having been asso- 

 ciated with any gastro-intestinal or other 

 troubles. Careful enquiry into these 

 cases was made, with the result that in 

 one case the evidence was absolutely 

 useless, and in the second case, the meat 

 which was supposed to have conveyed 

 the infection had been kept for several 

 hours in evidently insanitary sur- 

 roundings subsequent to cooking. In 

 neither of these cases was any ex- 

 perimental evidence forthcoming. 



From these cases, and probably from 

 the circumstances of the present out- 

 break, it can be fairly inferred that due 

 regard to ordinary cotnmonsense sanitary 

 precautions, in the prservation of meat 

 and other foods, in pantries, kitchens, 

 restaurants, and other places, would 

 obviate any possibility (if such exists) 

 of contamination with micro-organisms 

 which may perhaps have a pathogenic 

 action for man, but which have been 

 foucd to be of very considerable benefit 

 to mankind in general in destroying 

 filthy verminous animals, whose very 

 existence is a perpetual menace to the 

 public health, especially of the in- 

 habitants of large cities.— British Medical 

 Journal. 



HOW TO VANQUISH THE 

 MOSQUITO. 



An American paper says that a very 

 simple and perfectly effective method of 

 destroying mosquitoes is to make use of 

 permanganate of potash. Two and a 

 half hours are required for the develop- 

 ment of the full-tjrown mosquito from 

 the larva. It can be instantly killed 

 either in its infancy* or at maturity, by 

 contact with minute quantities of this 

 chemical. A solution of the salt, con- 

 taining only one part in 15,000 of water, 

 distributed in swamps and waterholes 

 where mosquitoes breed, will render the 

 development of the larvae impossible. 

 A handful of permanganate will oxidise a 

 10-acre swamp, kill all its embryo insects, 

 and keep it free from organic matter 

 at a cost of 25 cents (12|d.). An effica- 

 cious method is to scatter a few crystals 

 wide apart. A single pinch of perman- 

 ganate has killed all the germs in a 1,100- 

 gallon tank. The above is from " The 

 Public Health Journal," U. S. A. 



Some years ago we noticed large 

 numbers of mosquito larvae in a small 

 waterhole at Nundah. A few months 

 later none were to be found in it, but 

 by some means or other (probably by 

 the help of birds or cattle, carrying fish 

 spawn on their feet), this waterhole 

 became alive with briliantly-coloured 

 fish, about 2 in. long. Doubtless these 

 little fish destroyed the larvae. Con- 

 firmation of this theory we now find in 

 an article in the London " Times," re- 

 published in the "Journal of the 

 Jamaica Agricultural Society " for Sep- 

 tember, 1908. It is as follows : — 



5£ lthas long been known that Bar- 

 badoes is the only West Indian island 

 that is absolutely free from malaria 

 and from the presence of the anopheles 

 mosquito. Major Hodder, R. E., in 

 his report to the War Office three 

 years ago on the drainage works that 

 were then being carried out in St. 

 Lucia, came to the conclusion that there 

 was some hitherto undiscovered reason 

 why the anopheles failed to propagate 

 its kind in Barbadoes where the culex 

 was abundant. It appeared from his 

 observations that the anopheles could, 

 or did, only breed on the ground level ; 

 none of its larvaa being found in tanks 

 which were raised a few feet from the 

 earth, nor even in those which were 

 actually resting on the ground. The 

 culex can, on the other hand, breed in 

 the gutters on the roots of high build- 

 ings as easily as in the low-lying swamps 

 and pools. My friend Mr. C Kenrick Gib- 

 bons, who had given a good deal of 

 attention to the matter pointed out at 



