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SCIENCE. 



[Vol. XVIII. No. 450 



managers, however, to conduct original and intelligent ex- 

 plorations, rather than merely to accumulate a large quan- 

 tity of " Indian relics" by purchase, and arrangements are 

 now making for the placing of several men in the field who 

 are experts in this kind of scientific work. 



Meanwhile the valley of the Delaware is being carefully 

 attended to, and has yielded largely, much material having 

 been collected that throws additional light on the customs 

 and conditions of the Indians that for so many centuries oc- 

 cupied this region. During the summer of 1891 a large 

 number of village sites were exhaustively explored, and two 

 interesting rock shelters examined ; while on an island in 

 the river was found an implement maker's work-shop, and a 

 "cache" where 116 beautifully chipped knives, averaging 

 about six inches in length, was brought to light. The flint 

 (jasper) quarry from which the Indians derived their raw 

 material for arrow-heads, knives, scrapers, and drills was 

 also located; the shaft they had sunk exammed, and a vast 

 quantity of cores, chips, unfinished implements, and ham- 

 mers, mauls, and other implement-making tools, were pro- 

 cured. 



Recently, through the generosity of several gentlemen, 

 the superb Cope collection was secured, so that even now 

 the museum has excellent facilities for illustrating the con- 

 ditions of human life on this continent prior to European 

 contact. 



The first annual report, a pamphlet with beautiful illus- 

 trations, has already appeared, and, better than all else, 

 shows how rapid has been the progress of the venture. 



Altogether it appears probable that an institution has been 

 founded which will become not only a source of great local 

 pride and influence in Philadelphia, but will powerfully ad- 

 vance the cause of this most interesting of sciences through- 

 out America. The need of money is great, and the rich men 

 of the country, especially those who are alumni of the Uni- 

 versity of Pennsylvania, or interested in this part of the 

 country, can flud here a use for a portion of their wealth 

 which will be most fruitful in the advancement of knowl- 

 edge. It is to be hoped, too, that many persons in the 

 Southern and Middle States, who have formed small local 

 collections of archaeological specimens, will see the wisdom 

 of depositing them in this general museum, where they can 

 do far more general good than hidden in isolated houses 

 scattered about the country. May every success attend this 

 new museum, and long live Dr. Abbott, its curator. 



Ernest Ingersoll. 



INFLUENCE OF GROUND WATER UPON HEALTH.' 



The examination of the historic records or of the published 

 mortality tables of this and other countries shows that there are 

 certain conditions which are found to be present when certain 

 diseases are most rife. It is also found, that, after eliminating 

 certain meteorological and other influences which are supposed to 

 affect disease, some particular diseases appear to be solely influenced 

 by the hvKrometric condition of the ground and the volume of 

 water which is present in the ground. 



In historic periods when particular epidemics have been rife, 

 they have mostly occurred in times of drought, in which it has 

 been established, beyond doubt, by the evidence of the failure 

 of springs and rivers, that the ground water was then exception- 

 ally low. 



Tbe actual measurements of the ground water in this country, 

 in some cases, go back for a period beyond that of the registration 

 of deaths, consequently a comparison can be made between the 



1 Abstract of a paper read before the Congress of Hygiene, in London, Eng- 

 land, August, 1891, by Baldwin Latham, F.G.S, 



State of the ground water and the death-rate of any particular 

 period ; and when such examination is made it is found that there 

 is a coincidence between the state of the ground water and the 

 deaths recorded. The deaths follow, as a rule, in the inverse ratio, 

 the state of the lowest ground water; that is, high low water in- 

 dicates a healthy period, while low low water marks the unhealthy 

 periods. Investigations respecting the influence of ground water 

 upon health should be studied over limited areas, as the distribu- 

 tion of rain is often very local, and there are varieties in the geo- 

 logical character of the soil that affect the result of observations 

 carried on over large areas, and on this account, while observa- 

 tions have been carried on by the author over an extended area, 

 he has always used local observations to compare with the mor- 

 tality returns in the same district, and he has specially dealt with 

 the records of Croydon, which is the place where the observations 

 as to percolation, evaporation, and the hygrometric condition of 

 the soil have been locally studied. 



There is every reason to believe that the ground water itself, 

 except when polluted, exercises no influence as a cause of disease, 

 but is merely the measure or indicator of the influences which 

 are at work within a polluted soil, and of certain organic changes 

 which evidently take place within the dark recesses of the soil, 

 and which lead to the development of the conditions favorable to 

 a certain class of disease. That the earth does exercise a baneful 

 effect upon health is well known from the experience in this coun- 

 try of the unhealtlifulness of cellar dwellings, and from the fact 

 that persons habitually living upon ground floors are not so healthy 

 as those living in the upper stories of buildings removed from the 

 influence of the ground. 



There is a seasonable fluctuation in the waters in the ground, 

 and, as a rule, these waters are lowest in the autumn and early 

 winter, and highest in the spring or early summer; but in some 

 years the period of both low and high water varies, as, for exam- 

 ple, the low water of last season did not take place until February 

 of this year (1891). 



It is also known that the artificial lowering of the sub-soU waters 

 of a district has produced the same effects upon the health as 

 occurs when a general lowering of the ground water arises natu- 

 rally from drought. 



Tbe actual drying of the ground is a condition which is favora- 

 ble to the general good health in this country, and this circum- 

 stance often masks, in the general death-rate, the potential influ- 

 ence of certain diseases, so that the general health of a district 

 appears to be good, while at the time it may suffer intensely from 

 a certain class of disease of which low ground water is the indi- 

 cator. When, however, the conditions become extremely intense, 

 and the ground water exceptionally low, the influences at work 

 affect the death-rates as a whole. On the other hand, in periods 

 of excessive rain with high ground water, the conditions are 

 usually favorable to health, and all places in which the ground 

 waters are of a uniform level, sucli as seaside places, which are 

 governed by the mean tide level, and i-iver valleys with porous 

 soils, like that of the River Wandle, in which the water is headed 

 up to a uniform level by mills, are usually healthy. 



It is known that the measure of the effect of the ground water 

 is most marked in districts which draw their water supply from 

 the ground, and amongst that section of the inhabitants who use 

 such water for dietetic and other purposes, especially in the case 

 of young children and teetotallers. 



The unhealthy time after the period of excessive low water is 

 that when the fli'st rain begins to percolate through the soil, just 

 as if it washed out matters which had been specially prepared or 

 were retained in the dark recesses of the soil, into the water, or by 

 driving out the ground air specially charged with the poison of 

 disease. It is by no means uncommon both in this and other 

 countries to find that particular epidemic outbreaks which have 

 become rife at a low-water period can be traced to particular rain- 

 falls. In this country since we have the registration of deaths, 

 those quarters of the jear when percolation has first commenced 

 after periods of exceptionally low water are, without exception, the 

 most unhealthy seasons that have been recorded. The quarters of 

 the year when percolation first commenced after exceptionally 

 low water have been the most unhealthy, as, for example, the 



