664 



SCIENCE. 



[N. S. Vol. XX. No. 516. 



demands radical reform. A method that 

 has not only reduced the deaths fj-om ty- 

 phoid fever by about 75 per cent., but has 

 also reduced the number of cases propor- 

 tionately, is worthy of universal adoption. 

 If the fatality in all cases of typhoid fever, 

 was diminished, say, from 12 per 100 cases 

 to 3, by the use of a new drug or an anti- 

 toxin the world would ring with the dis- 

 covery. The introduction of a pure water 

 supply has achieved an analogous reduc- 

 tion in the death rate and confers further 

 the enormous benefit of preventing the oc- 

 currence of a similar proportion of cases. 

 In the city of Albany, N. T., the annual 

 number of deaths from typhoid fever prior 

 to the installation of a filter plant aver- 

 aged 89 during a ten-year period; in 1902 

 there were but 18 deaths from this cause, 

 representing a diminution not only of 71 

 deaths, but of over 700 cases. 



Important as is the function of a pure 

 water supply in preventing typhoid fever, 

 it is now clear that public hygiene can not 

 stop here. In some countries, as in Ger- 

 many, for example, where the larger cities 

 and towns are supplied in the main with 

 water of a highly satisfactory character, 

 there still remains a notable residue of 

 cases of typhoid fever. These we know 

 are due to contact infection, to contamina- 

 tion of raw foods, such as milk, oysters and 

 the like, to the conveyance of the specific 

 germ on the bodies of flies and to similar 

 modes of dissemination. It is a fact full 

 of significance that the existence of these 

 various modes of spread is recognized, that 

 they are held to be matters of public 

 concern and that preventive measures are 

 being instituted under expert bacteriolog- 

 ical control for suppressing the existing 

 sources of infection. One of the most diffi- 

 cult problems in this campaign lies in the 

 prompt recognition and rigorous supervi- 

 sion of the mild and obscure cases. It may 

 be comparatively simple to isolate and dis- 



infect with thoroughness in the franker 

 types of the disease, but it is not clear that 

 the danger is most critical on this side. 

 The application of searching and delicate 

 bacteriological tests is often necessary to 

 determine the suitable mode of action. 

 The dependence of public hygiene upon 

 bacteriological data and methods has rarely 

 been better exemplified. 



The vigorous warfare that is being waged 

 against malaria in many tropical countries 

 affords a further and striking illustration 

 of the utilization of existing resources for 

 the avoidance of specific infection. It is 

 hardly necessary to reiterate the obvious 

 truth that malaria constitutes the chief 

 and, perhaps, the only serious obstacle to 

 the colonization of the tropics by the white 

 races. Political and economic questions of. 

 the gravest import to mankind are bound 

 up with the fortunes of a protozoon and a 

 mosquito. The complex life-cycle of the 

 malarial parasite offers an unusual number 

 of points of attack. As is well known, sev- 

 eral distinct views are current as to the 

 best way of interrupting the continuity of 

 transfer between man and the mosquito. 

 It is conceivable that by the destruction of 

 the malarial parasite within the body of 

 man the supply of parasites for the mos- 

 quito may be cut off and the circle broken 

 at this point. If the mosquitoes are pre- 

 vented from becoming infected, man is 

 safe. It is claimed by the adherents of 

 one school that this method has proved 

 very effective in certain localities where 

 it has been systematically employed. The 

 extermination of the parasite in the blood 

 of man by the administration of quinine 

 certainly constitutes an important weapon 

 in the armory of public hygiene, whether 

 or not it prove to be the most efficient 

 one or the most economical in execution. 

 In this same category are to be put the 

 attempts to prevent the infection of the 

 mosquito by guarding malarial patients 



