February 9, 191 1] 



NATURE 



471 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for opinions 

 expressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications.] 



Drainage and Malaria. 



The writer of the paragraph upon Drainage and 

 Malaria in the " Notes " of Nature for September 15, 

 1910, is evidently unaware that the facts as they relate 

 to Klang and Port Swettenham, the two stations men- 

 tioned, lend themselves to a quite dififerent interpretation 

 from that put forward. The idea conveyed by the para- 

 graph referred to is that two intensely malarious places 

 have been freed from malaria by drainage alone, with a 

 - iving of more than 400 lives per annum. 



A study of the reports that have been published from 

 time to time .by Drs. Travers and Watson, the medical 

 officers who claim to be responsible for this remarkable 

 achievement, reveals the following facts. 



Klang is the principal town in a district of that name 

 In the Federated Malay States. Port Swettenham is a 

 new port situated five miles from Klang. It was opened 

 in 1901. The total population of Klang district for 1901 

 was 18,110, of which 3576 belonged to Klang town. In 

 iqo3 the population of Klang and Port Swettenham 

 together was estimated at about 4000. 



From i8q8 to 1904 the total deaths registered in the 

 town and district together were as follows : — 



1898 iS^g 1900 190T 1902 T903 1Q04 

 Total deaths ... 475 5=8 780 998 547 543 612 

 Rate per 1000 ... 26-3 310 430 55-4 303 30-1 34-0 



It will be seen from this table that the mortality rose 

 very markedly in 1900 and 1901, and fell sharply in 1902. 



."Vn analysis of the returns shows this to have been due 

 to an extraordinary temf>orary increase in the mortality 

 of Klang town during these two years. The following 

 table gives the mortality in the towns from 1900 to 1904 

 compared with that of the rest of the district : — 



igoo 1901 1902 1903 1904 



Towns i"^°^^' 474 582 144 "5 122 



\ Per 1000 ... 132-5 1627 364 287 30-5 



nUrrJrf '"^°*^* 306 416 402 428 490 



^'^"*"\ Per 1000 ... 21-8 297 287 30-5 350 



A consideration of these figures indicates that some special 

 Influence must have been at work in Klang~town to cause 

 the appalling mortality of 1900-1, and the history of local 

 events gives the clue to this. 



At one time Klang was both port and railway terminus 

 of the district, but in 1897 it was decided to construct a 

 new port five miles beyond Klang. The site chosen was 

 a mangrove swamp partially submerged by every high 

 tide ; and for the reclamation of this, the making of 

 railway embankments and the construction of approaches 

 to the wharves and building sites, earth had to be brought 

 from a distance. While the work was in progress, the 

 coolie labourers employed suffered severely from malaria, 

 which increased in severity as the work approached com- 

 pletion. The health of the town was also affected, and 

 when at last the new port and railway were opened on 

 September 15, 1901, and a large number of Government 

 servants and others connected with the shipping were 

 transferred from Klang to quarters at Port Swettenham, 

 many of them contracted malaria. 



This appears to have seriously alarmed the authorities, 

 wfio had remained unmoved at the fearful mortality that 

 had taken place before the opening of the new ix>rt, and, 

 as a result, steps were taken to draw up a scheme for 

 the drainage of both stations. Meanwhile, quinine was 

 freely administered as a prophylactic with such good 

 effect that a marked improvement was recorded even 

 before the drainage schemes could be executed. The 

 epidemic which had raised the mortality to such a frightful 

 figure in iqoo and 1901 declined very rapidly after the 

 opening of the port and railway, and the total number of 

 deaths during 1902 was less than one-quarter of those 

 in 1901. 



To those acquainted with conditions in the tropics, the 



NO. 2154, VOL. 85] 



occurrence of an epidemic of malaria during the con- 

 struction of a new port and railway, and its disappearance 

 after the completion of the work, occasions no surprise, 

 for it is just what has happened hundreds of times in the 

 past. 



In the East, the coolie labourers employed on such 

 works are drawn almost entirely from the poorest and 

 most ignorant classes of the population ; they are often 

 brought long distances and set down in a country in 

 which the climate, and even the food obtainable, differs 

 greatly from that to which they are accustomed ; if housed 

 at all, they are generally crowded into temporary huts, 

 but frequently they are left to find what shelter they can ; 

 they have often no one to look after them when sick, and 

 no means of obtaining food if for any reason they are 

 unable to work. Their work is arduous and their pay 

 small, and owing to the fact that they generally try to 

 save money for the support of dependants at home, it is 

 no uncommon thing to find them attempting to exist upon 

 a miserably insufficient diet. Camped as they usually are 

 upon the site of the work, their surroundings are almost 

 always highly insanitary-, for there is rarely any pretence 

 at a conservancy system, and sometimes no proper water 

 supply ; and if much earth-work is going on, the numerous 

 pools of water formed during the rainy season speedily 

 become the breeding places of countless swarms of 

 mosquitoes. In these circumstances it is not surprising 

 that coolie labourers on large public works should be 

 decimated by outbreaks of epidemic disease. But what- 

 ever happens to the coolies, the work has still to go for- 

 w-ard, so that as long as it is in prepress there is con- 

 tinual immigration of new labourers to fill the gaps caused 

 in the labour force by sickness, desertion, and death. 

 This continual immigration is a further source of mis- 

 chief, for the constant introduction of gangs of susceptible 

 newcomers into camps which have already become hot- 

 beds of disease increases the trouble, just as the addition 

 of fuel to a glowing fire increases the blaze. 



Those who, like the writer of this letter, have watched 

 the course of epidemics of this kind among Indian coolies, 

 cannot fail to trace in the history of events at Klang and 

 Port Swettenham a similar occurrence. It may be re- 

 marked that the epidemic at these places began among 

 the labourers on the work, and increased in severity as 

 that work progressed ; it occasioned a fearful mortality, 

 such as is never seen except in conditions similar to those 

 described above ; and just as its origin can be traced to 

 the construction of the new port and railway, so also can 

 its decline be traced to the completion of this work. Once 

 a big project of this kind is finished, the labour force 

 rapidly disperses, immigration of the class of labour 

 employed ceases, a settled population takes its place, and 

 conditions as regards health rapidly approach the normal 

 once more. 



In these circumstances it becomes difficult, if not 

 impossible, to estimate the value of the drainage projects 

 that were carried out at Klang and Port Swettenham 

 after the decline of the epidemic, for it is certain that 

 in any case there was bound to be a great improvement 

 after the completion of the work on the new port and 

 railway, and the dispersal of the labour force engaged on 

 their construction. The only legitimate method of test- 

 ing the results of the drainage of the two stations is the 

 comparison of the mortality rates of Klang prior to the 

 commencement of construction work for the new port 

 and railway with those recorded after the introduction of 

 the drainage schemes, and until this has been done it is 

 misleading to claim these places as demonstrating the 

 value of drainage in combating malaria. 



As for the statement that more than 400 lives per 

 annum have been saved bv the drainage of Klang and 

 Swettenham, it is an absurd fiction based on the ridiculous 

 assumption that but for the drainage schemes the 

 enormous rate of mortality recorded in 1901 would have 

 continued unchecked. Chas. A. Bextley. 



Bombay, October 22, 19 10. 



I HAVE read with interest Dr. Bentlev's interpretation 

 of the figures relating to the anti-malari.il works at Klang 

 and Port Swettenham oublished by Dr. Travers and 

 myself, and I am familiar with Dr. Bentlev's valuable 

 paper on the human factor in malaria. This factor is. 



