bination of a combustible substance with oxygen is, under all circumstances, the only source of animal heat. In whatever way carbon may combine with oxygen, the act of combination is accompanied by the disengagement of heat. It is indifferent whether this combination takes place rapidly or slowly, at a high or at a low temperature: the amount of heat liberated is a constant quantity.

The carbon of the food, being converted into carbonic acid within the body, must give out exactly as much heat as if it had been directly burned in oxygen gas or in common air; the only difference is, the production of the heat is diffused over unequal times. In oxygen gas the combustion of carbon is rapid and the heat intense; in atmospheric air it burns slower and for a longer time, the temperature being lower.

It is obvious that the amount of heat liberated must increase or diminish with the quantity of oxygen introduced in equal times by respiration. Those animals, therefore, which respire frequently, and consequently consume much oxygen, possess a higher temperature than others which, with a body of equal size to be heated, take into the system less oxygen. The temperature of a child (102°) is higher than that of an adult (99.5°). That of birds (104° to 105.4°) is higher than that of quadrupeds (98.5° to 100-4°) or than that of fishes or amphibia, whose proper temperature is from 2.7° to 36° higher than that of the medium in which they live. All animals, strictly speaking, are warm-blooded; but in those only which possess lungs is the temperature of the body quite independent of the surrounding medium.

The most trustworthy observations prove that in all climates, in the temperate zones as well as at the equator or the poles, the temperature of the body in men, and in what are commonly called warm-blooded animals, is invariably the same; yet how different are the circumstances under which they live!

In the animal body the food is the fuel; with a proper supply of oxygen we obtain the heat given out during the oxidation or combustion of that fuel. In winter, when we take exercise in a cold atmosphere, and when consequently the amount of inspired oxygen increases, the necessity for food containing carbon and hydrogen increases in the same ratio; and by gratifying the appetite thus excited, we obtain the most efficient protection against the most piercing cold. oxygen taken into the system is given out again in the same form, both in summer and winter. We expire more carbon at a low than at a high temperature, and require more or less carbon in our food in the same proportion; and, consequently, more is respired in Sweden than in Sicily, and in our own

The

country an eighth more in winter than in summer. Even if an equal weight of food is consumed in hot and cold climates, Infinite Wisdom has ordained that very unequal proportions of carbon shall be taken in it. The fruits used by the inhabitants of southern climes do not contain, in a fresh state, more than 12 per cent. of carbon, while the blubber and train oil which feed the inhabitants of polar regions contain 66 to 80 per cent. of that element.

From the same cause it is comparatively easy to be temperate in warm climates, or to bear hunger for a long time under the equator; but cold and hunger united very soon produce exhaustion.

A starving man is soon frozen to death. The animals of prey in the Arctic regions, as everyone knows, far exceed in voracity those of the torrid zone.

In cold and temperate climates, the air, which instantly strives to consume the body, urges man to laborious efforts, in order to furnish the means of resistance to its action, while, in hot climates, the necessity of labour to provide food is far less urgent.

Our clothing is merely an equivalent for a certain amount of food. The more warmly we are clothed, the less urgent becomes the appetite for food, because the loss of heat by cooling, and consequently the amount of heat to be supplied by the food, is diminished.

Were we to go naked, like certain savage tribes, or if in hunting or fishing we were exposed to the same degree of cold as the Samoyedes, we should be able with ease to consume half of a calf, and perhaps a dozen of tallow candles into the bargain, daily, as warmly clad travellers have related with astonishment of these people. We should then also be able to take the same quantity of brandy or train oil without bad effects, because the carbon and hydrogen of these substances would only suffice to keep up the equilibrium between the external temperature and that of our bodies.

INSURANCE, COMMISSION, BROKERAGE, ETC.

(1) What is the commission on £5,000 at 2s. 6d. or per cent.?
(2) What is the brokerage on £11,250 at 7s. 6d. per cent.?
(3) What is the commission on £1,010 at 35s. per cent.?

(4) What is the brokerage on £609 11s. 3d. at £3 10s. per cent.?
(5) What is the commission on £7,689 10s. at 2s. 6d. per cent.?
(6) What would be the insurance on £63,768 at 3s. 2d. per cent. ?

SELECTIONS FROM THE POEMS OF PRIOR, ADDISON, AND POPE.

(Matthew Prior.)

[Born, 1664; died, 1721. Chief Works: 'Solomon,' and Miscellaneous Poems.]

Pro-to'-ge-nes, a painter of Rhodes, who
flourished B.C. 328

A-pel'-les, a painter of Cos, who lived at
the same time as Protogenes
mis'-sive, anything sent as a letter, &c.

ex-pa'-ti-ate, to range at large, to en-
large upon

un-tu'-tor-ed, untaught
pro-pi'-tious, favourable

di-late', to spread out, to speak at large

PROTOGENES AND APELLES.

WHEN poets wrote and painters drew,
As nature pointed out the view;
Ere Gothic forms were known in Greece,
To spoil the well-proportion'd piece;
And in our verse ere monkish rhymes
Had jangled their fantastic chimes;
Ere on the flowery lands of Rhodes,
Those knights had fixed their dull abodes,
Who knew not much to paint or write,
Nor car'd to play, nor dar'd to fight:
Protogenes, historians note,

Liv'd there, a burgess, scot and lot;
And, as old Pliny's writings show,
Apelles did the same at Co.

Agreed these points of time and place,
Proceed we in the present case.
Piqu'd by Protogenes's fame,
From Co to Rhodes Apelles came,
To see a rival and a friend,
Prepar'd to censure or commend;
Here to absolve, and there object,
As art with candour might direct.
He sails, he lands, he comes, he rings;
His servants follow with the things:
Appears the governante of th' house,
For such in Greece were much in use:
If young or handsome, yea or no,
Concerns not me or thee to know.
Does Squire Protogenes live here ?
Yes, sir, says she, with gracious air
And curtsy low, but just called out
By lords peculiarly devout,

Who came on purpose, sir, to borrow
Our Venus for the feast to-morrow,

To grace the church, 'tis Venus' day :
I hope, sir, you intend to stay,
To see our Venus, 'tis the piece

The most renown'd throughout all Greece;
So like th' original, they say:
But I have no great skill that way.
But, sir, at six ('tis now past three)
Dromo must make my master's tea:
At six, sir, if you please to come,
You'll find my master, sir, at home.

Tea, says a critic, big with laughter,
Was found some twenty ages after;
Authors, before they write should read.
'Tis very true; but we'll proceed.

And, sir, at present would you please
To leave your name-Fair maiden, yes.
Reach me that board. No sooner spoke
But done. With one judicious stroke,
On the plain ground Apelles drew
A circle regularly true:

And will you please, sweetheart, said he,
To show your master this from me?
By it he presently will know

How painters write their names at Co.
He gave the panel to the maid.
Smiling and curtsying, sir, she said,
I shall not fail to tell my master:
And, sir, for fear of all disaster,
I'll keep it my own self: safe bind,
Says the old proverb, and safe find.
So, sir, as sure as key or lock-
Your servant, sir, at six o'clock.
Again at six Apelles came,
Found the same prating civil dame.
Sir, that my master has been here,
Will by the board itself appear.
If from the perfect line be found
He has presum'd to swell the round,
Or colours on the draft to lay,
'Tis thus (he order'd me to say),
Thus write the painters of this isle,
Let those of Co remark the style.

She said, and to his hand restor❜d
The rival pledge, the missive board.
Upon the happy line were laid
Such obvious light and easy shade,
The Paris' apple stood confess'd,

Or Leader's egg, or Chloe's breast.
Apelles view'd the finished piece;
And live, said he, the arts of Greece!
Howe'er Protogenes and I

May in our rival talents vie ;
Howe'er our works may have express'd
Who truest drew, or colour'd best,
When he beheld my flowing line,
He found at least I could design:
And from his artful round I grant,
That he with perfect skill can paint.
The dullest genius cannot fail
To find the moral of my tale;
That the distinguish'd part of men
With compass, pencil, sword, or pen,
Should in life's visit leave their name
In characters which may proclaim
That they with ardour strove to raise
At once their arts and country's praise;
And in their working, took great care
That all was full, and round, and fair.

THE BATTLE OF BLENHEIM.

(Joseph Addison.)

[Born, 1672; died, 1719. Principal Works: Various Poems, the Tragedy of Cato,' and his celebrated Essays, which appeared in the Spectator.']

BUT now the trumpet, terrible from far,
In shriller clangours animates the war;
Confed'rate drums in fuller concert beat,
And echoing hills the loud alarm repeat:
Gallia's proud standards to Bavaria's join'd,
Unfurl their gilded lilies in the wind;
The daring prince his blasted hopes renews,
And while the thick embattled host he views
Stretch'd in deep array, and dreadful length,
His heart dilates, and glories in his strength.

The fatal day its mighty course began,
That the griev'd world had long desir'd in vain ;