REVIEW — TKOPICAL MEDICINE, ETC. 91 



(?)) grains which are surrounded by a ring of protoplasm, and which are so small as only to be Hydrophobia 

 visible eii, masse. — continued 



Eemlinger,' in an important paper, states that spontaneous recovery of experimental 

 rabies can take place in the dog and that the rabic virus can persist in the saliva 

 of recovered animals. The points he raises require confirmation, and are under the 

 consideration of a special Committee. 



Ice. A paper on the Pollution and Self-Purification of Ice, in the Monthly Bulletin, 

 New York State Department of Health, of March, 1907, will amply repay perusal to all 

 those responsible for the public health, and more especially in hot climates. 



It is pointed out that there are very few cases on record where intestinal diseases have been traced to ice as 

 the vehicle of infection and that, of these, one must clearly distinguish between intestinal disturbances caused by 

 decomposing organic matter, and diseases, such as typhoid fever or cholera, caused by the specific germs. Some 

 half-dozen supposed ice-borne epidemics, chiefly of enteric fever, are cited, and the conclusion come to is that the 

 evidence is by no means reliable. 



Ice may be infected because derived from polluted water, natural ice may be contaminated in situ, and either 

 natural or " artiticial " ice m.ay be rendered impure during manufacture, handling or distribution. The last- 

 mentioned is by far the most serious mode of infection, for it leaves the time interval, between infection and 

 transmission, too short for any counteracting influence of cold to be exerted. The influences effecting self- 

 purification of ice are : — 



1. The phenomenon of subsidence and oxidation upon suspended matters, including bacteria in bodies of 

 quiescent or slowly flowing water. This, of course, applies chiefly to ice from lakes and ponds. In rivers, 

 however, it is found that in a run of from 10 to 15 miles, from 50 per cent, to 75 per cent, of the bacteria are 

 removed by this means. 



2. The removal of suspended and dissolved matters brought about during the freezing process, the so-called 

 " filtration process of freezing." This in general effects a reduction of about 90 per cent, of the suspended 

 particles and bacteria and also eliminates to a certain degree chemical compounds in solution. 



3. And, most important, the effect of low temperature. The special point to note is that the period of 

 exposure is of greater importance than the degree of cold. It is said that bacteria are reduced in number about 

 50 per cent, after exposure to freezing temperatures for one hour ; 90 per cent, after 24 hours ; and practically 

 100 per cent, after two to three weeks. The few killed after a month are so attenuated as to be unable to produce 

 disease. 



4. The general tendency to the destruction of pathogenic bacteria when exposed or disseminated through a 

 body of water. This is no doubt due in part to unfavourable environment and in part to the hostile action of the 

 common water bacteria. It is thus evident that in most instances it is the storage, handling and distribution of 

 ice which require special attention from the standpoint of a health officer. 



As regards Khartoum, a few remarks on this subject will be found under " Sanitary 

 Notes" (Third Eeport). 



Infectious Diseases. Under this somewhat comprehensive title we propose to 

 consider only one point, namely, the early diagnosis of infectious diseases by recognition 

 of the involvement of lymph glands. 



Vipond- has a very interesting paper on the former subject, and his conclusions may 

 bo quoted with advantage. He says : — 



1. The nodes are enlarged in infectious diseases. 



2. They are enlarged some days before the development of the disease. I have found them to be enlarged 

 and tender seven days before the rash of measles appeared. 



3. The enlargement is most marked between the ages of from three to 18 years. 



4. The enlargement is not produced by the irritation of the rash, but is due to the absorption of the poison 

 or toxin. 



5. As a rule nursing infants do not contract infectious diseases readily, as the tonsils are small and inactive. 



6. The tendency to contract infectious disease would be much lessened if the mouth and tonsils were in a 

 healthy condition. 



7. The enlargement of the nodes is more marked in certain infectious diseases than in others. For instance, 

 they are larger in erysipelas, measles and rubella than in scarlet fever and whooping-cough. 



8. They resolve more quickly in diphtheria under the influence of antitoxin than they do in measles and 

 erysipelas. 



9. In all infectious diseases (except those of local incubation) the poison most likely enters the system 

 through the tonsils. 



10. Suppuration does not take place in the nodes unless we are dealing with a mixed infection. 



^ Remlinger, P. (November, 1907), "Spontaneous Recovery of Experimental Babies in the Dog and the 

 Persistence of the Rabic Virus in the Saliva of Recovered Animals." Journal of Tropical Vdcrinarij Science, p. 393 



- Vipond, A. E. (December loth, 1906), "The Early Diagnosis of Infections Diseases by the Recognition of 

 the General Involvement of the Lymphatic Q-landular System." British Medical Journal, p. 1710, Vol. II. 



