292 



SCIENCE. 



[Vol. XIV. No. 352 



motor attached to the propeller-shaft. A case containing the 

 high explosive is carried in a chamber in the forward end. This 

 chamber slopes downward, so that the torpedo, which has a rocket 

 attachment at its rear end, will be thrown down and out on being 

 released. It is also porposed to invert the boat when occasion 

 may require, and provide means for throwing the torpedo from this 

 chamber into the air, so that it may fall on a vessel's deck. 



The position of the opening to this torpedo-chamber may be 

 seen in the illustration, as the small chain connecting with the har- 

 poon in front is attached to the torpedo. When the harpoon 

 strikes a wooden bottom, it is expected to penetrate deeply enough 

 to hold. When it passes through a torpedo-net, the harpoon-head 

 will pass through the meshes till the cross-arms are reached, when 

 a spring catch is released allowing other cross-arms to open inside 

 the net, and nearer the harpoon-head. In any event, the harpoon 

 is held. At the same time the torpedo is released, the rocket 

 chamber in its rear end is ignited, and the torpedo discharged 

 downward. The chain attachment to the harpoon-head then 

 compels a swinging motion, so as to bring the torpedo up against 

 the vessel's bottom. 



While all this is going on, the automatic arrangements have re- 

 versed the boat, and carried it away from its dangerous position, so 

 that the operator may then guide it safely back for use in another 

 attack. 



AMERICAN PUBLIC HEALTH ASSOCIATION. 



On the second day, Wednesday, Oct. 23, Dr. John S. Billings of 

 the United States Army read a paper on " The United States 

 Census in its Relation to Sanitation." He emphasized the impor- 

 tance of the collection of vital statistics. Many do not regard this 

 as so important as other work in behalf of public health. In order 

 to convince the press and the community that the work of a board 

 of health is necessary, you must produce constant, undeniable evi- 

 dence ; and this evidence must be mainly death-rates, to which 

 should be added all the sickness-rates obtainable. To do this 

 there must be a complete registration of deaths and births, and an 

 enumeration of the whole population. Before this association 

 meets again, the eleventh United States census will have been 

 taken, and its methods and results are of great interest to all sani- 

 tarians. One of the most important questions to be settled before 

 the census is taken is, " What shall be the boundaries of the spe- 

 cial districts of the city for which a separate statement of the 

 population is desired ? " In some cities the wards form fairly 

 satisfactory districts for the purpose, and where this is the case it 

 makes the problem very easy. But in many cities these divisions 

 bear no proper relation to different sanitary conditions : therefore 

 in about a dozen of our large cities it is proposed to make a sys- 

 tematic division of the area into sanitary districts having special 

 relations to altitude, character of habitations or of population, etc., 

 and to have special death-rates calculated for each of these dis- 

 tricts. This is being done in conference with the health authorities 

 of these cities, and it is hoped that in this way some very interesting 

 data will be obtained which will serve as a foundation for sanitary 

 work in the future. 



To make the statistics as correct and useful as possible, all deaths 

 occurring in hospitals should be charged to the ward or district of 

 the city from which the patient was taken to hospital, when this 

 can be ascertained ; otherwise the death-rate in the ward in which 

 the hospital is located will be too high, and in the other districts it 

 will be too low. The birthplace of the parents of the decedent 

 should be also reported. Moreover, it is very desirable that in all 

 cases of deaths of colored persons it should be stated whether the 

 decedent was black or of mixed blood, such as mulatto or quad- 

 roon. One of the most important questions in the vital and 

 social statistics of this country relates to the fertility, longevity, and 

 liability to certain diseases, of those partly of negro and partly of 

 white blood ; and the only way to obtain data on this subject 

 is through the registration of vital statistics. For all cities of ten 

 thousand inhabitants and upward, it is proposed to collect as com- 

 plete information as possible with regard to altitude, climate, water- 

 supply, density of population, sewerage, proportion of sewered and 

 non-sewered areas, and other points bearing on the healthfulness 



of the place which will permit of interesting comparisons with the 

 death-rates. The cordial co-operation of all physicians and sani- 

 tarians is solicited in making the data of these reports accurate and 

 complete. It is desired to make these vital statistics an unanswer- 

 able argument in favor of systematic public sanitary work and of 

 the granting of State and municipal funds necessary for maintain- 

 ing such work. 



In a paper by Dr. Ezra M. Hunt, secretary of the State Board of 

 Health, Trenton, N.J., on " The Prevention of Phthisis Pulmonalis, 

 and Methods for its Limitation," the author criticised those who 

 regard the infection of phthisis pulmonalis as exclusively due to 

 inhalation of the dried sputa of this disease. The theory was ad- 

 vocated that the breath of a consumptive patient is capable of 

 carrying the contagion. 



Dr. W. M. Smith, quarantine officer of the port of New York, 

 read a paper on " Improvements at the New York Quarantine 

 Station." 



An excursion to the Quarantine and East River Hospitals, ac- 

 companied by Dr. Smith, took up most of the day. 



At an evening session, Dr. George M. Sternberg, U.S.A., gave 

 an account of recent researches relating to the etiology of yellow- 

 fever. The investigations were made in Havana, between the 

 middle of March and the first of September, 1889. Ample material 

 has been obtained for a thorough research by modern culture 

 methods. Thirty autopsies have been made in typical cases of 

 yellow-fever. The cultures obtained require further study and ex- 

 tended comparative research before any definite conclusion can be 

 reached as to the specific etiological relation of one or other of the 

 micro-organisms found in yellow-fever cadavers, principally in the 

 intestine. One method followed in the entire series of cases was 

 the preservation of a piece of liver or kidney in an antiseptic wrap- 

 ping, by which the exterior was sterilized and the entrance of germs 

 from without prevented. Such a piece, after forty-eight hours in, 

 the laboratory, appeared fresh, and had no odor, but when cut was 

 found to contain various micro-organisms. The cut surface had 

 an acid re-action. The bacilli were of various species, and corre- 

 sponding with those found in the contents of the intestine. No 

 satisfactory evidence has been obtained, up to the present time, 

 that any one of these is the veritable yellow-fever germ. One of 

 the most constantly found of these micro-organisms was a large 

 motionless, anaerobic bacillus, resembling that of malignant oedema. 

 This, and others found in a less number of cases, were present in 

 small numbers at death, and in a large proportion of cases the re- 

 sult of an examination made immediately from fresh liver-tissue 

 was negative. Material from a piece of liver, kept as above, and 

 containing micro-organisms, is very pathogenic for guinea-pigs 

 when injected subcutaneously in small quantities, while the fresh 

 tissue may be injected in considerable amount without noticeable 

 effect. The micrococcus of Freire has not been found in any 

 cultures of this series, and the bacilli of Finlay and Gibier have not 

 generally been found in the tissues of yellow-fever cadavers. 



Dr. Theobald Smith of Washington read some preliminary ob- 

 servations on the micro-organism of Texas fever. Cultures have 

 been made from the spleens of animals who died of Texas fever, 

 and a variety of bacteria found. A variety of experiments led to 

 the discovery of an organism within the red blood-corpuscles. The 

 intraglobular bodies found are round or oval, and nearly colorless. 

 There is usually one, but two or more may be found in one cor- 

 puscle. 



This was followed by a paper by D. E. Salmon, D.V.M., chief 

 of the Bureau of Animal Industry, Washington, entitled " Some 

 General Observations on Texas Fever." The resemblance in the 

 characteristics of yellow- fever in man and Texas fever in cattle 

 was noticed. Each disease has a permanently infected and well- 

 known district which is its home. The contagion of both diseases 

 is carried, not by the sick, but by the healthy. Natives in the in- 

 fected districts have a certain immunity from disease, while non- 

 residents entering the locality will contract the fever. Both dis- 

 eases, when carried north of their home, require a period of warm 

 weather for development. Neither contagion survives a winter of 

 snow and frost beyond its home. Both diseases are accompanied 

 by an inflammation of the liver which causes yellow discoloration 

 of the tissues, and in both hsmaturia is seen. These points of 



