P OP ULAR MIS CELL ANY. 



285 



turn, are said to be " often striking, always 

 clever, and generally abominable." The 

 great fault of most modern camco-cutters 

 is an excessive fondness for detail. 



Ground-Water and Health — Mr. Bald- 

 win Latham, C. E., declares, as the conclu- 

 sion derived from eleven years of investiga- 

 tion, that there is generally a parallelism 

 between the conditions, of health and the 

 volume of ground - water. The years in 

 which there has been a large quantity of 

 ground-water present have invariably been 

 the healthiest years, while those in which 

 there has been a small quantity have invari- 

 ably been the most unhealthy periods. As 

 a rule, the lowncss of the ground-water in- 

 dicates the future health, and not the state 

 of health at the particular time of lowness ; 

 that is, the unhealthy period, as a rule, 

 follows the period of low water, the de- 

 gree of lowness indicating the intensity of 

 future disease. In some instances an un- 

 healthy period runs concurrently with the 

 period of low water, but in all these cases 

 there is clear evidence that percolation 

 has begun before the unhealthy period 

 comes on. These results, which are con- 

 firmed by observations made at Paris, differ 

 from those obtained by Professor Petten- 

 kofer, at Munich, in that he there found 

 typhoid fever and low water concurrent ; 

 in all other respects they agree with his. 

 There is also clear evidence, derived from 

 experience in England, that the lowering 

 of the subsoil water by artificial means 

 produces a tendency to the development and 

 dissemination of typhoid fever. It is clear, 

 however, to the author's mind, that ground- 

 water itself has no influence, either for 

 good or evil, upon health, but that the low- 

 ness or highness of the water in the ground 

 is the index of conditions which greatly 

 influence the health of all communities. We 

 have periods of abundance of water, and 

 periods of low water, with both healthy and 

 unhealthy conditions. Ground -water has 

 been shown by Professor Pettenkofer to be 

 chemically more impure in periods of high 

 water when the conditions were favorable 

 to health than when there is a low state of 

 the ground-water and a condition unfavor- 

 able to health. The records also show that 

 we have periods when rain has started into 



existence malignant diseases ; while, on the 

 other hand, we have similar heavy rain- 

 falls accompanied by a high state of public 

 health. The records clearly point out that 

 it is not one circumstance alone which pro- 

 duces disease, but that there are at least 

 three factors concerned in the matter, espe- 

 cially in the case of typhoid fever, viz. : the 

 elements which produce disease, such as a 

 polluted state of the ground ; the conditions 

 which are necessary for the development 

 of disease, such as a period of dryness of 

 the ground in those regions which water 

 usually occupies, combined with a compara- 

 tively high degree of temperature ; and con- 

 ditions which will lead to the spread of the 

 disease, such as the probable influence of 

 a storm or rain in driving impurities out 

 of the ground into our water-supplies, or 

 through the instrumentality of ground-air 

 passing into our habitations, and its recep- 

 tion by a population which is in a condition 

 to receive such germs of disease. If any of 

 these conditions is absent, diseases like ty- 

 phoid do not occur. It has been pointed 

 out by Professor Pettenkofer that in those 

 districts in which the rivers are held up at 

 uniform levels by rains, the conditions are 

 favorable to health, and cholera seldom be- 

 comes epidemic. This is corroborated in 

 great measure by the state of health at sea- 

 side resorts, which being at the natural out- 

 flow for gi'ound-water, and owing to the 

 imif orm height of mean tide-level are placed 

 in a condition favorable to health. 



Hints in Object-Teaching.— Mrs. Sarah 

 J. Hale, in a little book on " Infant-School 

 Management," gives some excellent precepts 

 for interesting children in subjects of study 

 and making them at home in them. "In 

 every case," she says, " the teacher must 

 bring plenty of illustration to bear upon 

 the lesson. In natural history the real ani- 

 mal, or a picture, should be exhibited, and 

 if possible something that it furnishes us 

 with, as, for instance, the fur of the otter, 

 the shell of the tortoise, the quills of the por- 

 cupine. The teacher should also carefully 

 provide herself with pictures of animals 

 which afford strong contrasts to those with 

 which she is dealing, as well as those which 

 bear some general resemblance to it, that 

 she may exercise the discriminative as well 



