SOME ASPECTS OF TROPICAL SANITATION 251 



our Sanitary Inspector, but not towards Musca domestica, which he slays in large numbers The sun an 

 in AjJril and May. I have noticed frequently how rapidly the number of house-flies 

 diminishes once the sun attains his summer power. Sunlight, however, is not only 

 operative on soil and soil conditions ; it affects in a very marked manner the bacterial 

 content of superficial waters, and, as you may know, Clemesha, in India, has proposed to 

 employ the effects of sunlight on water bacteria as a means of arriving at a suitable 

 bacteriological standard for such waters in tropical countries. It is a fortunate thing that 

 the bacteria with the most evil significance from a hygienic standpoint, appear to be those 

 most susceptible to the action of sunlight. 



We must, however, remember that there is a great difference between the action of 

 the sun under moist conditions and its effects when the climate is dry. It is only in the 

 latter state that the sun is able to exercise its full beneficial effects, and one of the first 

 things a Sanitary Inspector has to recognise in a country like the Sudan is the difference 

 between the dry and the rainy seasons. It is true that the rainj' season in Khartoum is, 

 as a rule, trivial, but every now and then the rains become for a time torrential, and, 

 with a soaked, though rapidly drying, soil, a humid atmosphere, and a considerable influgn^e of 

 temperature, bacterial activity is stimulated, and it is well if, at the same time, the activity humidity 

 of the Sanitary Inspector increases to keep pace with, and eventually surpass, that of such 

 pathogenic organisms as the Bacillus typhosus and the Bacillus dijsenteriie. 



The sun, then, on the whole is a good friend. Sad to relate, he must also be classed 

 amongst the enemies, for his effects on the Sanitary Inspector himself are not always 

 beneficial. What tropical resident has not, at times, dreaded the molten mass mounting 

 rapidly to his zenith, and has not breathed a sigh of relief when old Sol, for one night 

 only, has taken his last peep over the edge of the world ? During the long summer, from 

 April to November, the conditions, save during July and August, are undoubtedly trying. 

 The sun's heat is exhausting, the sunlight is apt to play havoc with the nervous system, 

 there is the risk, a slight one under dry conditions, of sunstroke and of sunheadache. One 

 has to spur oneself to exertion, and the best of men is apt to flag. The sun becomes 

 a foe, but he may aid the Medical Ofiieer of Health at such times by enabling him to 

 weed out the fit from the unfit, by acting as a test of eflBciency and devotion. Next 

 to the sun, dryness and lack of rain, as already indicated, are good allies. In the Sudan 

 the character of the population is also a favouring factor. The people, if treated with Native 

 tact and discretion, and if their few religious and racial prejudices are respected, are easy pop"'ii';°"5 

 to manage. There is no enmity towards the Sanitary Inspector. He is known as a attitude to the 

 benefactor, and it is rare to find squabbles and disputes arising. We cannot practise 1"^?'='='°'" 

 the militant hygiene of Panama, and there is, as a rule, no need for stringent measures. 

 In part this is due to apathy, in part to the habit of obedience inculcated in those living 

 under British rule, and in part to an intelligent understanding and a desire to co-operate 

 in work which is for the public weal. 



Above all things, we have no cultured fanatics. The anti-vaccinationist has not yet 

 raised his voice in the desert. The native is intelligent, and readily appreciates the value 

 of Jenner's great discovery, for to him for many years small-pox was a dread calamity, 

 while now it is becoming well-nigh as extinct as the dodo, or at least as rare as the 

 whale-headed stork of our southern swamps. 



Still, the apathy already mentioned leads me to class the character of the population 

 also under the foes of the Inspector. His chief difficulty is with the Egyptians and with 

 low-class Greeks and Italians, for the Arab and the black Sudani are cleanly races, and 

 a Sudanese location is usuallv a model of cleanliness if not of comfort. The habits of 



