74 



PHYSICAL GEOGRAPHY. 



[PART I. 



belt of the blue sky interposing between them. 1 In 

 Ceylon this is doubtless owing to the air holding in 

 suspension a large quantity of vapour, which receives 

 shadows and reflects rays of light. The natives, who 

 designate them "Buddha's rays," attach a superstitious 

 dread to their appearance, and believe them to be porten- 

 tous of misfortune in every month, with the exception 

 of May, which, for some unexplained reason, is exempted. 

 HEALTH. In connection with the subject of "Cli- 

 mate," one of the most important inquiries is the 

 probable effect on the health and constitution of a Euro- 

 pean produced by a prolonged exposure to an unvarying 

 temperature, upwards of 30 degrees higher than the 

 average of Great Britain. But to this the most tran- 

 quillising reply is the assurance that mere heat, even to a 

 degree beyond that of Ceylon, is not unhealthy in itself. 

 Aden, enclosed in a crater of an extinct volcano, is not 

 considered insalubrious ; and the hot season in some 

 parts of India, where the thermometer stands at 100 at 

 midnight, is comparatively a healthy period of the year. 

 In fact, in numerous cases heat may be the means of 

 removing the immediate sources of disease. Its first per- 

 ceptible effect is a slight increase of the normal bodily 

 temperature beyond 98, and, simultaneously, an increased 

 activity of all the vital functions. To this everything 

 contributes an exciting sympathy the glad surprise of 

 the natural scenery, the luxury of verdure, the tempting 

 novelty of fruits, and all the unaccustomed attractions 

 of a tropical home. Under these combined influences 

 the nervous sensibility is considerably excited, and the 

 circulation acquires greater velocity, with slightly dimi- 



1 VIGNE mentions an appearance 

 of this kind in the valley of Kashmir : 

 " Whilst the rest of the horizon was 

 glowing golden over the mountain 

 tops, a broad, well-defined ray- 

 shaped streak of indigo was shooting 

 upwards in the zenith : it remained 

 nearly stationary about an hour, 

 and was then blended into the sky 



around it, and disappeared with the 

 day. It was, no doubt, owing to 

 the presence of some particular 

 mountains which intercepted the red 

 rays, and threw a blue shadow, by 

 causing so much of the sky above 

 Kashmir to remain unaffected by 

 them." Travels in Kashmir) vol. ii. 

 ch. x. p. 115. 



