149 



particularly suspicious when the rats have been dying throughout a week 

 or longer and not sinuiltaneously, as shown by the different degrees 

 of decomposition of the bodies. In the latter case the mortality niight 

 be due to poison, fumigation abroad, etc. ; but the former conditions 

 would certainly be due to an epizootic, which in the author's 

 experience has proved to be plague in 50 per cent, of the cases. 



The routine application of rat-guards to ropes, etc., seems to be of 

 little value in preventing rats from getting to land. For the campaign 

 ashore, buildings must be constructed so as to leave no nesting places, 

 and in warehouses rat-catchers must be employed in addition. During 

 1916 some 10,000 rats were destroyed by the public lat-catchers at 

 Liverpool. Poison had no great success, and, when successful, it 

 usually led to grave complaints. The same applies to the use of virus, 

 of which however little experience was had. The only virus successful 

 over any considerable period was one prepared by a bacteriologist and 

 constantly kept up in strength by repeated passage through rats. 

 The replacement of ashpits by sanitary bins very generally 

 throughout the city has largely driven rats from the residential parts. 



CopEMAN (Lieut.-Col. S.M.). The Prevention and Arrest of certain 

 Epidemic Diseases in War Time. — Jl. State Medicitie, London, xxv, 

 nos. 4-5, April-May 1917, pp. 103-115, 129-143, 4 charts. 



The contents of this review are indicated by its title. The control 

 of lice is briefly dealt mth in connection with the prevention of 

 typhus. 



NicoLL (W.). Flies and Typhoid.-^/, of Hygiene, Cambridge, xv, 

 no. 4, February 1917, pp. 505-526. 



The experimental work detailed in this paper was carried out from 

 1909 to 1912. The results are incomplete and are published in the 

 absence of any opportunity of amplifying them. 



The author's summary and conclusions are as follows : (1) The 

 chain of evidence incriminating the house-fly as a disseminator of 

 typhoid fever is at present fairly complete, but many of the Hnks are 

 weak and not thoroughly strengthened by experimentation. (2) The 

 biill< of experimental work has hitherto been done under highly 

 unnatural and artificial circumstances, and the results so obtained can- 

 not be accepted unreservedly as giving a correct view of conditions in 

 nature. (3) The experiments described in the present paper show that 

 flies can ingest typhoid bacilli from natural matter, i.e., human faeces 

 and urine, and carry them for a certain period of time. (4) There is no 

 evidence to show that the typhoid bacilh multiply in the house-fly. 

 On the contrary the evidence goes to show that they are not adapted 

 for prolonged hfe on or in the fly. (5) It thus follows that the house-fly 

 is a purely mechanical carrier of the typhoid bacillus and is not a 

 natural " host " in the strict sense of the term. (6) Many baciUi closely 

 resembhng Bacillus typhosus in cultural characteristics appear to be 

 natural or, at least, common inhabitants of the intestine of the house- 

 fly. These are extremely likely to be mistaken for B, typhosus unless 

 the most stringent tests are employed. (7) As might be expected, there 



