General Science . 
407 
posed to have an acute sense of smell, for no sooner does a per- 
son stop where leeches abound, than they appear to crowd 
eagerly to the spot from all quarters. u Those who have had 
no experience of these animal s,” says Dr Davy, 6C of their im- 
mense numbers in their favourite haunts, — of their activity, 
keen appetite, and love of blood, can have no idea of the kind 
and extent of annoyance they are to travellers in the interior, 
of which they may be truly said to be the plague. In rainy 
weather, it is almost shocking to see the legs of men on a long 
march, thickly beset with them, gorged with blood, and the 
blood trickling down in streams. In attempting to keep them 
off, they crowd to the attack, and fasten on quicker than they 
can be removed. I do not exaggerate, when I say that I have 
occasionally seen at least fifty on a person at a time. Their 
bites are apt to fester, and become sores, and frequently de- 
generate into extensive ulcers, which, in too many instances, 
have occasioned the loss of limb, and even of life."’ — Dr Davy’s 
Account of the interior of Ceylon. 
27. Removal of a Paralytic Affection by Lightning. — Mr 
Olmsted, Professor of Chemistry in the College of North Caro- 
lina, has published, in the American Journal of Science, vol. iii. 
No. 1. p. 100. an account of the removal of a paralytic affec- 
tion by a stroke of lightning. Mr Samuel Leffers of Carteret 
County, North Carolina, had been affected with a paralytic af- 
fection in his face, which had settled chiefly in the eye. When 
he was walking in his house during a thunder storm, he was 
struck down by lightning. After lying senseless fifteen or 
twenty minutes, he recovered so far as to be sensible of his si- 
tuation. He recovered the use of his senses and of his limbs 
by degrees, during the remainder of the day and night, and he 
felt so well the next day, that he was inclined to give to a dis- 
tant friend an account of what had happened. He was able to 
write a long letter, without the use of glasses. Since that time 
he never felt a symptom of the paralytic disorder ; and he con- 
cluded, that it had been effectually cured by the shock. He 
thought, however, that the same cause which restored his sight 
impaired his hearing. 
28. Altitude of Dhwalagiri and other Moun tains of the Hima- 
laya.-— The superior altitude of the Himalaya range to the moun- 
