458 L. Rogers — Relationship of the water-supply, water-logging [No. 4, 



used by Major Dyson in the Punjab in a similar inquiry, and by others, 

 and is perhaps the most reliable and easily carried out method, especially 

 in the season of the year when fever is at a minimum. Secondly, the 

 level of the ground-water was taken in as many wells as possible, and 

 inquiries were made as to the height to which the ground-water rose 

 during the rainy season, so as to enable the degree of water-logging to 

 be estimated. Thirdly, the drinking-water supply was carefully noted. 

 Fourthly, the number of fever cases treated at various dispensaries 

 month by month was compared with the monthly rainfall over a series 

 of years, and worked out in charts, in order to ascertain the influence 

 of seasons and rainfall on the fever rate. Lastly, some observations 

 have been made on the distribution and monthly variations of the 

 distribution of the Anopheles Mosquitos, which have furnished some 

 rather surprising results. 



In carrying out the spleen-count the whole area was divided up 

 into thirteen Municipalities, and as far as possible 100 persons, about 

 half of whom were children, were examined in each Ward of each 

 Municipality, over 5,000 persons having been examined in all. As 

 children suffer from enlarged spleen more commonly than adults, just 

 as Koch has recently shown that the malarial organism is also found 

 in a larger percentage of children, the figures have been corrected 

 so as to represent the spleen rate of 50 children and 50 adults in each 

 Ward, so that the figures of the different areas should be strictly 

 comparable. Visits were made from house to house so as to get a fair 

 sample of the actual inhabitants of the Wards, and every precaution 

 was taken to obtain accurate results, every single person being examined 

 by myself, a month being taken over the inquiry. 



The results are embodied in the accompanying map, in which the 

 different municipal areas are shaded in accordance with the percentage 

 of persons who were found to have enlarged spleens, the darker areas 

 representing the highest percentages and vice versa. The dotted lines 

 within the municipal areas enclose the Wards or areas separately 

 examined, and the large figures within them indicate the spleen per- 

 centage, while the figures enclosed in a circle are those of the distance 

 of the ground water-level below the surface in feet and inches, the 

 upper figures being the distance in the dry cold weather taken in the 

 month of February, while the lower ones indicate the distance during 

 the height of the previous rainy season. The small figures in brackets 

 refer to the number of the Wards given in the left-hand margin of the 

 map, and correspond with those in the tables given further on. 



The general results of the spleen-count. 

 The following table shows the percentage of people who were found 



