248 



SCIENCE. 



[Vol. XI. No. 277 



ordinary gas-burner uses over six feet of gas per hour : one 

 mechanical horse-power at our oil-engine can supply twelve cor- 

 responding incandescent electric lights ; or 1.7 pints of oil must be 

 compared with 72 feet of gas ; roughly, 24 pints of oil will equal 

 1,000 feet of gas. The quality of oil used cannot cost as much as 

 ten cents per gallon : at that price the oil for our engine will com- 

 pare with gas at thirty cents per thousand. To this we must add 

 about fifteen cents for breakage of lamps, making forty-five cents 

 per thousand. The amount to be added for interest and deteriora- 

 tion depends entirely upon the amount of light used : for an ordi- 

 nary household, using four or five thousand feet of gas a month, this 

 item might amount to a dollar a thousand at a very liberal esti- 

 mate, making the total cost one dollar and forty-five c^nts a thou- 

 sand at the outside, and giving all the advantages that incandescent 

 lighting offers, — greater health, convenience, comfort, and beauty, 

 with the use of small motors for various domestic purposes. 



Accumulator Tests. — The London Electrician contains the 

 following : " Prof, von Waldenhofen has recently carried out at the 

 Electro-Technical Institute a comprehensive series of experiments 

 with the storage-cells of the Fahrbarky and Schenck, l^eckenzaun 

 and Julien type. The chief object of the experhnents was to ascer- 

 tain the efficiency of each type, especially for tramway purposes, 

 and to eliminate errors in estimating the degree to which the cells 

 had been charged or discharged. The experimenter based his in- 

 vestigation on three measurements ; viz., the electro-motive force 

 on open circuit, the density of the electrolyte, and the potential 

 difference when at work. The efficiency of the Reckenzaun ac- 

 cumulator was found to be 89.3 per cent for quantity, and 80.5 per 

 cent for energy. For the Julien accumulator, the figures were re- 

 spectively 89.7 per cent and 83,4 per cent ; whilst the Schenck- 

 Fahrbarky accumulator gave 91 per cent efficiency for quantity, 

 and 78.5 per cent for energy." These figures are interesting; but as 

 the efficiency of any accumulator varies greatly with the rate of 

 discharge, decreasing as the discharge rate increases, it would be 

 well to give with the efficiencies the rate of discharge at which they 

 were obtained. As the experiments were for tramway-work, how- 

 ever, we may assume that rather heavy currents were used : this 

 being the case, the tests are most encouraging. 



The Bently-Knight Electric Tramway in Allegheny 

 City. — This line is about four miles in length, and employs 

 both overhead conductors and conduits. In both cases there is a 

 complete metallic circuit, neither the rails nor earth being used as 

 a return. The road is difficult, with one grade of 9! feet in loo 

 feet for a distance of 400 feet, and numerous others ; the average 

 rise in a distance of 4,900 feet being 295 feet, — over six per cent. 

 Two fifteen-horse power motors are used under each car, con- 

 nected with the axles by spur-gearings. There are at present four 

 cars running, with two more to be added shortly. 



HEALTH MATTERS. 

 State Medicine. 



At the meeting of the American Medical Association held in 

 Cincinnati during the present month. Dr. H. P. Walcott, chairman 

 of the State Board of Health of Massachusetts, delivered the annual 

 address on State medicine. For the following abstract of the ad- 

 dress we are indebted to the New York Medical Record.: — 



Dr. Walcott first related briefly the history of the State Board of 

 Health of Massachusetts, which was established by legislative ac- 

 tion in 1S69. Its duties were at first advisory rather than executive ; 

 but, in proportion as public intelligence in sanitary matters was 

 quickened, the functions of the board were enlarged, until now it 

 is charged to some extent with the power of enforcing the rights of 

 the people to pure air, soil, water, and food, and preventing and 

 punishing any violation of them. It is also intrusted with the busi- 

 ness of gathering information concerning any matter pertaining to 

 public health, and diffusing such information among the people. 

 Among the chief of its duties in this connection is the investigation 

 of the causes and the prevention of infectious diseases. A compari- 

 son of the mortality statistics will show in a measure the effect 

 which all this work has had upon the health of the people. The 

 number of deaths from all causes, in proportion to the population, 



has changed but little during a period of thirty-six years, ending 

 with 1886; but the percentage of deaths from zymotic diseases has 

 almost steadily decreased, during the period that the State Board 

 has been in existence, from 25.6 to ig.o: there has also been a gen- 

 eral tendency, though less markfed, in the direction of a decrease of 

 deaths from constitutional diseases. The classification of prevent- 

 ible diseases is as yet not well defined ; and year by year, as the 

 experience of sanitarians becomes widened, a larger and larger 

 number of affections are found to be the result of influences that 

 can be removed. This fact is illustrated in the case of consump- 

 tion, the prevalence of which was shown twenty-five years ago by 

 a former president of this association, Dr. H. G. Bowditch, to be 

 largely influenced by conditions of soil, moisture, and land-drain- 

 age. The most marked reduction has occurred in the case of 

 small-pox, which is a disease that is absolutely preventible by means 

 of vaccination and re-vaccination. In demonstration of the sav- 

 ing of life in consequence of better sanitary conditions, the speaker 

 offered a comparison between the results of ovariotomy and those 

 following the labors of an intelligent and efficient board of health. 

 The largest number of deaths in Massachusetts in any one year 

 from ovarian dropsy was 51. In the single city of Somerville the 

 death-rate has been reduced, since the organization of a municipal 

 board of health, from 22.86 to i6.68 per thousand. Thus the adop- 

 tion of sanitary measures has saved more lives in one year, in a 

 community of thirty thousand people, than could have been restored 

 to health in the same period in a State of nearly two millions of in- 

 habitants, by an operation which is justly regarded as one of the 

 greatest triumphs of American surgery. In has been said by Dr. 

 Russell of Glasgow that nothing is more conspicuous than the 

 helplessness of the individual, under the conditions of civilized life, 

 to secure the physical basis of health. How can any single individ- 

 ual in a crowded city detect and remove all possible causes of dis- 

 ease in the water, food, sewerage, and air contamination ? There 

 is no help but in co-operation on the most extended scale possible, 

 — individual, municipal. State, and national. The individual must 

 be compelled to give up the liberty to injure his neighbor ; the city 

 must be restrained from converting into a sewer the river vvhich 

 supplies water to the villages that cluster about its banks lower 

 down in its course; no State should permit its own causes of dis- 

 ease, whether they are persons or things, to be transported into an- 

 other State; lastly, the general government should take cognizance 

 of those causes of disease which can be controlled by no other 

 power. A sufficient safeguard will never be established by volun- 

 tary associations on the part of persons, towns. States, or even na- 

 tions. How, then, shall we organize for the protection of the pub- 

 lic health ? For the individual, the speaker maintained : " Let the 

 State give him some assurance that the legally used title of physi- 

 cian designates a person sufficiently qualified to give advice for the 

 prevention and cure of disease ; establish, by direct provision of 

 State law, local health authorities for each village, town, city, or 

 county; and, to control all these local organizations, let there be a 

 State board, clothed with ample powers." All arguments that have 

 been used for the existence of State health authorities. Dr. Walcott 

 believed, are also available for the creation and support of some 

 central health authority. The question of form of this organization 

 is one that may be left to the law-making powers. A board in 

 which every State was represented might be cumbersome, but it 

 could easily delegate its povvers to a small and compact executive 

 committee during the intervals between the necessarily infrequent 

 meetings of the full board. The only alternative to this seemed to 

 the speaker to be a single officer at the head of a bureau in connec- 

 tion with some one of the departments at Washington. This cen- 

 tral authority, however constituted, should have ample means for 

 investigating into the State boards of health. There is still in legal 

 existence a national board of health ; but, through the neglect of 

 Congress, it is in a state of hopeless lethargy. This board entered 

 upon its work with every promise of success, and it demonstrated 

 that local. State, and national health authorities could profitably and 

 harmoniously unite in suppressing an epidemic of yellow-fever, and 

 preventing its spread from State to State ; yet this did not save it 

 from practical extinction. The failure of the board to survive the 

 unjustifiable attack made upon it was due in great measure, the 

 speaker thought, to its organic form, embracing, as it did, members 



