;joo 



I'lii': wATUu-surri.Y or towns in tiiI'; tkoimcs 



Collection of 

 samples 



iippe'iir to lie a causi' of coinmunicablo flisuasc, for reasons I have stated elsewhere 

 (Third Ui'piul, Wellcome Tropical Jicsearvli lidhiirntories, li)OK, )>. H4). 



Water for washiiif;, cookiiij,', irri^atin-,' t^ardens and watering animals was, in the 

 main, derived from the numerous shallow wells with which the site of the town is 

 honeycombed. Such water is always impure from a chemical 

 standpoint and also from what we may call the English 

 bacteriological standpoint. It is hard, and often contains 

 li. colt of a " flaginac " and excretal type in so small a 

 quantity as 0-02 c.c. I have known B. pyocyaneus to be 

 present in such water and have also seen its use result in 

 dysentery, and systematic pinking of such infected water led 

 to a cessation of the cases it had caused. In this connection 

 I show a drawing (Fig. 95) of an excellent type of apparatus 

 for taking water samples from wells and rivers, of a type not 

 figured in the text books. 



It will be seen that it consists of a metal stirrup on which 

 the collecting bottle, of 2-50 c.c. capacity, rests. A steel rod 

 is attached to the stirrup, and, by screwing lengths of similar 

 rod together, any depth, up to 50 feet or so, can easily be 

 reached. A ring support holds the bottle in place and through 

 other rings a wire runs. This wire is attached to a pair of 

 flexible metal forceps which grasp the flat bottle stopper, and 

 are operated by a circular collar which can l)e slid up and 

 down. The stopper has a glass rod attaelied to it and when 

 the former is drawn out by the attachment, and checked from 

 coming up too far, by one of the metal rings, the glass rod is 

 not wholly withdrawn from the bottle neck and so guides the 

 stopper back into its place. 



The whole apparatus can be sterilised by the flame of 

 a blast lamp and is light, easily handled and exceedingly 

 convenient. 



It is a copy of one I saw in use in Vienna and was 

 made for me by Messrs. Baird & Tatlock, Ltd., of London. 



When the question of an improved w-ater-supply came up 

 evident that only two sources were available. 



1. The river; the supply to be taken above the town. 



2. Deep wells, if such could be obtained. 



The advantages of the river supply were, that the water was known to be palatable, 

 that there was an unlimited quantity, that it would l)e popular with the natives and 

 that the works required were not likely to be expensive. Its disadvantages were the 

 necessity for the construction of settling tanks unless the water could be obtained 

 through pipes sunk in the sand-banks, or by means of galleries beneath the river bed. 

 Moreover, as the river water was certainly liable to pollution from the banks and from 

 boats and steamers it could not be relied upon as a permanent supply without filtration, 

 and filters, even mechanical filters, are to be looked upon with suspicion especially in a 

 country where native labour has to be employed.* 



Fio. as.- 



Apporatun for coll<-ctiD^ wat«r. 



I !'t th« fiiiMi wrllx aoj livers, 

 :il analysis 



for consideration, it was 



' This was prior to the employment, on a lari?c scale, of ozone or the action of the ultra-violet rays for 

 water aterilisation. 



