May 4, 1888.] 



SCIENCE. 



213 



from five-horse power upward. The improvement consists in an 

 automatic arrangement by which the pressure between the clamps 

 is adjusted to compensate for irregularities in lubrication, etc. The 

 two clamps are connected by a system of levers, so arranged, that, 

 if there is a tendency for the whole system to revolve in the direc- 

 tion of revolution of the pulley, the pressure between the clamps is 

 decreased ; if it begins to move in the other direction, the pressure 

 increases. This seems a great improvement over the ordinary 

 Prony brake, and will be useful in measuring the eiificiency of 

 steam-engines, large electric motors, gas-engines, etc. It cannot, 

 however, replace transmission dynamometers for many purposes, 

 and it is probably not so efficient as the best of the latter class ; the 

 Tatham dynamometer, for example. It is an instrument that can 

 be cheaply made, and no doubt will be extensively used. 



HEALTH MATTERS. 



Cholera-Infantum and the Weather. 



At a meeting of the New York Academy of Medicine, held in 

 February, Dr. A. Seibert read a paper on cholera-infantum and the 

 weather. The frequency and fatality of this disease in this latitude 

 during the summer months make this subject one of great interest. 

 Dr. Seibert includes under the name ' cholera-infantum ' all cases 

 of acute gastro-intestinal catarrh in children under five years of age. 

 The basis for this paper was an experience of ten years (1878 to 

 1888) in the children's department of the German dispensary of 

 New York City, during which time 8,036 cases of gastro-intestinal 

 catarrh had been treated. The disease exists all the year round, 

 even in the coldest weather ; and the proportionate mortality, one 

 in four, is just the same in cold as in hot weather. This he claims 

 is shown not only by his own statistics, but also by those of the 

 board of health. The largest number of cases, however, occurred 

 during the summer months. Thus, in the ten Julys there were 

 2,443 cases, and in the ten Augusts 1,524 cases, while in the ten 

 Februarys there were only 117 cases. The number of deaths was 

 always much greater in July than in August. Thus, during the 

 ten years, the number of deaths reported in the city of New York 

 in the month of July was 12,428, and in August only 6,205. In 

 July, 1 88 1, when the mean temperature was 80°, the number of 

 cases treated in the dispensary was 290 ; in August of the same 

 year, when the mean temperature was 82°, the number of cases 

 was 223 ; and in September, when the mean temperature was 87°, 

 the number of cases was 137. During the summer months it was 

 found that the number of cases and of deaths bore no relation 

 whatever to the rise and fall of temperature, and the same was 

 true as regards the range of humidity ; so that warm, moist weath- 

 er did not predispose more to the disease than warm, dry weather. 

 No relation could be demonstrated between the prevalence of the 

 disease and the rainfall, and the same was true in regard to the 

 velocity of the air-current. According to prevalent opinion, the 

 months containing the greatest number of hot days ought to have 

 had the greatest number of cases and of deaths ; but there was no 

 evidence supporting this. It is evident. Dr. Seibert thinks, from 

 the facts, that hot weather is not necessary for the production of 

 the disease, but that warm weather is. Statistics show that in the 

 early part of the summer season, as soon as the minimum daily 

 temperature remains above 60° for a number of days (a week or 

 more), the disease becomes epidemic ; and this, no matter how 

 high above 60° the temperature may go, whether it is 75°, 80°, or 

 85°. His conclusions are as follows : First, Hot weather, either 

 dry or moist, is not necessary for the epidemic appearance of acute 

 gastro-intestinal catarrh ; Second, Warm weather, either dry or 

 moist, showing a minimum daily temperature of not less than 60", 

 brings on the epidemic every year, irrespective of the height of the 

 maximum daily temperature ; Third, The disease loses its epidemic 

 character as soon as the minimum daily temperature falls below 

 60", as in October ; Fourth, Therefore this disease cannot be 

 brought about by the direct effect of high temperature upon the 

 child's body. 



Dr. Seibert then went on to say that the lowest temperature of 

 each day was reached during the night ; and it was at this time 

 that the milk which furnished the principal food of so many young 

 children was brought into the city. It was often carried long dis- 



tances, being much jolted about, and absorbing impurities from the 

 time it left the cow : it was therefore only a question how far the 

 decomposition of the milk had advanced by the time it reached the 

 child. It was well known that a low temperature retarded decom- 

 position ; and Dr. Cyrus Edson, of the New York Health Depart- 

 ment, had informed him that in his experience he had found that 

 milk usually began to turn whenever its temperature reached 60° 

 or higher. Chief-Engineer Birdsall, of the Department of Public 

 Works, had also informed him, that, whenever the temperature of 

 Croton Lake rose to 60° or above, there was a peculiar taste about 

 the water, which he attributed to the decomposition of certain 

 matters contained within it. 



As to the point why there are always so many more cases and 

 deaths in July than in August, the difference usually amounting to 

 at least one-third, it seemed to him that it might perhaps be ex- 

 plained by the fact that it took a few weeks after the onset of warm 

 weather to fully arouse the tenement-house population to the 

 danger to which their children were exposed from this disease, and 

 to the necessity of taking suitable precautions as regards fresh air 

 and diet for its prevention. 



In the discussion which followed the reading of the paper. Dr. 

 L. Emmett Holt referred to some statistics of Liverpool which 

 tended to confirm some of Dr. Seibert 's conclusions. In one year 

 347 deaths occurred from cholera-infantum in July, the average 

 temperature being 58.9° F., while in August, when the temperature 

 was 59.2°F., there were 969 deaths. Dr. Holt said that in summer 

 there were different forms of diarrhosal disease in growing children, 

 and that he thought it was advisable that some distinction should 

 be made between them. In the production of what is ordinarily 

 known as ' summer- complaint,' he believed that there were foar 

 principal factors concerned, — namely, heat, feeding, sanitary con- 

 ditions, and constitution, — and that the most important of these 

 features was heat. 



Dr. J. Lewis Smith thought that there was perhaps a fallacy in 

 comparing summer diarrhoea with that of winter ; the two being, in 

 his opinion, very different diseases. He believed that summer-com- 

 plaint was due to heat, but just how this acted was not yet known. 

 Heat alone is not sufficient, else the disease would be prevalent in 

 the country as well as in the city. How much gaseous exhala- 

 tion had to do with its production was not ascertained. The opin- 

 ion is gaining ground that summer diarrhoea is a microbic disease. 

 It was'well known that milk which had begun to decompose had a 

 tendency to give rise to the affection. In Asiatic cholera the causa- 

 tive agency of Koch's bacillus had been pretty generally accepted, 

 and it was believed that this microbe was received into the mouth, 

 and acted as a source of irritation to the intestines by its actual 

 presence, and not by causing decomposition of food. In like man- 

 ner it did not seem unreasonable to suppose that micro-organisms 

 might act in the same way in some cases of summer diarrhoea. 



Dr. A. Caille thought that decomposing milk was the chief ex- 

 citing cause, while a high temperature paves the way. Two French 

 physiologists had made some experiments by exposing animals to 

 a continual temperature of 104°, and the phenomena which they 

 observed to result from the exposure were : (i) increase of 

 nervous excitability ; (2) nervous depression ; and (3) convulsions, 

 coma, and death ; death resulting more speedily in a moist high 

 temperature than in a dry high temperature. The same results 

 had been noticed to be produced in children when the weather was 

 very hot. It was his opinion, therefore, that while high tempera- 

 ture did not directly produce diarrhoea, it did have a pernicious 

 effect upon the system, and under these circumstances any irritat- 

 ing substance would be likely to give rise to diarrhoea. 



As regards the smaller number of cases of summer-complaint, as 

 well as of deaths from the disease, in August than in July, he 

 thought that perhaps one reason for this was that a much larger num- 

 ber of children left the city in August than in July, while those which 

 remained had the advantage of the numerous fresh-air excursions 

 then provided for the poor. 



Dr. A. Jacobi said that the cases which occurred were not all 

 alike. In some there was a simple catarrh, in others a tendency 

 to collapse. He thought that great heat would kill by its direct effect 

 on the heart, the myosin of the muscular tissue of that organ being 

 coagulated by the heat. Intense heat would cause a dilatation of 



