?8 



SCIENCE. 



[Vol. XIV. No. 339 



SCIENCE 



A WEEKLY NEWSPAPER OF ALL THE ARTS AND SCIENCES. 



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N. D. C. HODGES. 



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NEW YORK, August 2, i8 



No. 339. 



CONTENTS 



Electric Lighting bv the Knowles 

 System 67 



Description of Perret Motor? and '^ 

 Dynamos 6g 



Considerations concerning some 

 External Sources of Infection 

 IN THEIR Bearing on Preven- 

 tive Medicine 71 



Notes and News 73 



Editorial 78 



The World's-Fair Project. — Mos- 

 quitoes and Science. 

 Lucerne or Alfalfa 82 



Health Matters. 



Pneumonia 



Dr. Brown-Sequard's Hypodermic 



Fluid 



The Heredity of Myopia 



Electrical News. 



Wiring of Ships 



Book-Reviews. 

 Autobiography of Friedrich Froe- 



bel 



Among the Publishers . . 



Letters to the Editor. 

 A Circular Note to Working Ento- 

 mologists Robert H. Lambarn 

 Are Beech-Trees ever struck by 

 Lightning? D. L. Phares 



Breathing TIws. J. Mays 



The world's-FAIR project is moving on favorably. A meet- 

 ing of prominent representatives of American industries was held 

 at the office of the mayor of New York, where it appeared that the 

 proposition was well received by this class, upon whose efforts suc- 

 cess will depend. At this season many of New York's prominent 

 men are out of town, but there is no evidence that this will inter- 

 fere with the preliminaries of organization. Among the sugges- 

 tions floating in the air is that there should be minor exhibitions in 

 some of the other large cities of the United States, but it does not 

 appear that this side-show business will meet with acceptance. 

 At the mayor's meeting the appointment of four preliminary com- 

 mittees was decided on ; and the mayor is using due effort to 

 secure the right material for these, having invited the various com- 

 mercial and industrial organizations for suggestions. The finance 

 committee will be called on to secure a guaranty of something like 

 $15,000,000. The committee on the site will have necessarily a 

 delicate task, in view of the enormous interests which will be 

 affected ; but, with the many points in New York which can be 

 reached by land and water, there will be ample opportunity for a 

 good choice. The matter of legislation will call for due attention, 

 and, the more rapidly some results of the organization are to be 

 shown, the better will be the prospect of recognition at the hands 

 of Congress and the Legislature. What can be said now is that 

 the scheme takes with those who will carry it through. 



We would CALL attention to the letter by Dr. Lamborn in 

 this issue. We think all will agree that scientific methods should 

 be sought to lessen the number of mosquitoes, and that, where 

 even a glimmer of light is seen promising that consummation, it 

 should be followed by scientific men with the utmost vigor. New 

 Jersey alone could afford to spend a million dollars a year on any 

 plan that would largely lessen her mosquito-product. The Hfe- 

 history of any dragon-fly is yet but little known, and the character- 

 istics as destroyers of small insects of many of the scores of species 

 of dragon-flies is even less known. This attempt to get at facts 

 to reason upon we hope will meet with the aid of scientific persons 

 throughout the country, and that, with the results of this season's 

 work before us, we may be able to conclude how far the dragon- 

 fly may be used for the ends mentioned in Dr. Lamborn's letter. 



CONSIDERATIONS CONCERNING SOME EXTERNAL 

 SOURCES OF INFECTION IN THEIR BEARING ON 

 PREVENTIVE MEDICINE. 



{Continued from p. 73.) 



As regards anthrax bacilli, it has been determined that in ordi- 

 nary garden or field earth they do not multiply, but in earth con- 

 taminated by blood, urine, or fa;ces, their reproduction can occur. 

 They can grow on various vegetable substrata. There is no reason 

 to doubt, therefore, that the anthrax bacilli can find in or on the 

 ground suitable conditions for their multiplication, although such 

 conditions are not everywhere present. For durable infection of 

 the soil with anthrax bacilli, it is, however, more important that 

 these bacilli should find there suitable conditions for the formation 

 of spores than that they should be able simply to multiply. The 

 vegetative forms of anthrax bacilli would not, as a rule, be able 

 to survive for a great length of time the hostile influences which 

 they are likely to encounter in the ground ; such as insufficient 

 or exhausted nutriment, absence of sufficient moisture, and the 

 attacks of saprophytic organisms. On the other hand, against 

 these injurious influences the anthrax spores have great resist- 

 ance. In the superficial layers of the ground the anthrax 

 baciUi may often find those conditions of moisture, of temperature, 

 of oxygen-supply, and of insufficient food, which we know are most 

 favorable for the development of their spores : indeed, Soyka has 

 shown that the ground presents often these conditions better than 

 our culture media. A circumstance discovered by Feltz, which, 

 however, needs confirmation, is, if true, of not little significance. 

 He finds that anthrax bacilli may undergo a progressive diminution 

 in virulence in the soil. If this should be true likewise of other in- 

 fectious micro-organisms, we should be able to account in some 

 instances for the variable degree of virulence which clinical obser- 

 vation indicates that certain agents of infection acquire. So far as 

 anthrax bacilli are concerned, we may conclude, therefore, that the 

 ground occasionally offers suitable conditions for their reproduc- 

 tion ; but, what is of greater importance, it offers especially favor- 

 able conditions for their long-continued preservation in the form of 

 spores. I must forego here the further consideration of the special 

 circumstances inherent in the soil which control the origin and 

 spread of epidemics of anthrax in cattle, although many interest- 

 ing investigations have been directed to this subject. 



Of greater interest to physicians is the behavior of typhoid and 

 of cholera bacteria in the ground. As has already been intimated, 

 the ground is regarded by Pettenkofer and his school as the prin- 

 cipal breeding-place of these micro-organisms outside of the body. 

 This view, however, is not supported by bacteriological investiga- 

 tions. Inasmuch as the cholera and typhoid bacilli may multiply 

 on various vegetable substrata and substances derived from animals 

 at temperatures often present in the ground, it is evident that here 

 and there conditions may be present for their growth in the ground ; 

 but this growth is likely to be soon interrupted by the invasion of 

 ordinary saprophytic organisms and other harmful influences. The 

 typhoid bacilli are more hardy in resisting these invaders than are 

 the cholera bacteria, which easily succumb ; but even for the for- 



