THE EEASON WHY. 345 



He hath filled the hungry with good things ; and the rich he hath sent empty 

 away." LUKE i. 



of 100 miles from the surface, and that even in its present state very little 

 more than the soil on which we tread is fit for the habitation of organised 

 beings." 



The above is to be found in Mr. Timbs's " Things not Generally Known," a 

 little book which professes to set people right upon points on which they are in 

 error! 



Upon this subject Mr. Hunt, in his " Poetry of Science," says : 



133(5. " A question of great interest, in a scientific point of view, is the tempe- 

 rature of the centre of the earth. We are, of course, without the means of solving 

 this problem ; but we advance a little way onwards in the inquiry by a careful 

 examination of subterranean temperature at such depths as the enterprise of 

 man enables us to reach. These researches show us, that where the mean 

 temperature of the climate is 50 deg., the temperature of trie rock at 59 fathoms 

 from the surface is 60 deg.; at 132 fathoms it is 70 deg; at 239 fathoms it is 8<> 

 deg. ; being an increase of 10 deg. at 59 fathoms deep, or 1 deg. in 35.4 feet ; of 

 10 deg. more at 73 fathoms deeper, or 1 deg. in 43.8 feet ; and of 10 deg. more at 

 1 1* fathoms still deeper, or 1 deg. in 64.2 feet. 



Although this would indicate an increase to a certain depth of about one 

 degree in every fifty feet, yet it would appear that the rate of increase diminishes 

 w ith the depth. It appears therefore probable, that the heat of the earth, so far 

 as man can examine it, is due to the absorption of the solar rays by the surface. 

 The evidences of intense igneous action at a great depth cannot be denied, but 

 the doctrine of a cooling mass, and of the existence of an incandescent mass, at the 

 earth's centre, remains but one of those guesses which active minds delight in." 



Upon the subject of hunger and tJiirst, by which living creatures are prompted 

 to feast upon the bounties of nature, Sir Charles Bell says, in "Appendix to 

 Paley's Natural Theology :" 



1337. "Hunger is defined to be a peculiar sensation experienced in the stcmach 

 from a deficiency of food. Such a definition does not greatly differ from the 

 notions of those who referred the sense of hunger to the mechanical action ol 

 the surfaces of the stomach upon each other, or to a threatening of chemical 

 action of the gastric juice on the stomach itself. But an empty stomach does 

 i;ot cause hunger. On the contrary, the time when the meal has passed the 

 stomach is the best suited for exercise, and when there is the greatest alacrity 

 f f spirits The beast of prey feeds at long intervals ; the snake and other cold- 

 blooded animals take food after intervals of days or weeks. A horse, on the con- 

 trary, is always feeding. His stomach, at most, contains about four gallons, yet 

 throw before him a truss of tares or lucerne, and he will eat continually. The 

 emptying of the stomach cannot, therefore, be the cause of hunger. 



" The natural appetite is a sensation related to the general condition of the 

 system, and not simply referable to the state of the stomach; neither to its 

 action, nor its emptiness, nor the acidity of its contents ; nor in a starved 

 creature will a full stomach satisfy the desire of food. Under the same impulse 

 which makes us swallow, the ruminating animal draws the morsel from its own 

 stomach. 



1338. " Hunger is well illustrated by thirst. Suppose we take the definition of 

 thirst that it is a sense of dryness and constriction in the back part of the mouth 

 and fauces ; the moistening of these parts will not allay thirst after much fatigue 

 or d uring fever. In making a long speech, if a man's mouth is parched, and t ho 

 dryness is merely from speaking, it will be relieved by moistening, but if it 

 comes from the feverish anxiety and excitement attending a public exhibition, 

 his thirst will not be so removed. The question, as it regards thirst, was brought 

 to a demonstration by the following circumstance. A man having a wound low 

 down in his throat, was tortured with thirst : but no quantity of fluid passing 

 through his mouth and gullet, and escaping by the wound, was found in airy 

 degree to quench his thirst. 



" Thirst, then, like hunger, has relation to the general condition of the animal 

 ystem to the necessity for fluid in tb e circulation. For this reason, a man dying 



15* 



