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the structure of the masses in which they are found, and of the earth composed of those masses. The term Natural History is given to the three last branches taken together, but chiefly as far as they teach the classification of different things, or the observation of the resemblances and differences of the various animals, plants, and inanimate and ungrowing substances in nature.

But here we may make two general observations. The first is, that every such distribution of the sciences is necessarily imperfect; for one runs unavoidably into another. Thus, Chemistry shows the qualities of plants with relation to other substances, and to each other; and Botany does not overlook those same qualities, though its chief object be arrangement. So Mineralogy, though principally conversant with classifying metals and earths, yet regards also their qualities in respect of heat and moisture. So, too, Zoology, beside arranging animals, describes their structures, like Comparative Anatomy. In truth, all arrangement and classifying depends upon noting the things in which the objects agree and differ; and among those things, in which animals, plants, and minerals agree, or differ, must be considered the anatomical qualities of the one and the chemical qualities of the other. From hence, in a great measure, follows the second observation, namely, that the sciences mutually assist each other. We have seen how Arithmetic and Algebra aid Geometry, and how both the purely Mathematical Sciences aid Mechanical Philosophy. Mechanical Philosophy, in like manner, assists, though, in the present state of our knowledge, not very considerably, both Chemistry and Anatomy, especially the latter; and Chemistry very greatly assists both Physiology, Medicine, and all the branches of Natural History.—BROUGHAM.


The highest of all our gratifications in the contemplations of science remains: we are raised by them to an understanding of the infinite wisdom and goodness which the Creator has displayed in his works. Not a step can we take in any direction without perceiving the most extraordinary traces of design ; and the skill everywhere conspicuous is calculated, in so vast a proportion of instances, to promote

the happiness of living creatures, and especially of our own kind, that we can feel no hesitation in concluding that, if we knew the whole scheme of Providence, every part would be found in harmony with a plan of absolute benevolence. Independently, however, of this most consoling inference, the delight is inexpressible of being able to follow, as it were, with our eyes, the marvellous works of the Great Architect of Nature—to trace the unbounded power and exquisite skill which are exhibited in the most minute, as well as the mightiest parts of his system. The pleasure derived from this study is unceasing, and so various that it never tires the appetite. But it is unlike the low gratifications of sense in another respect: while those hurt the health, debase the understanding, and corrupt the feelings, this elevates and refines our nature, teaching us to look upon all earthly things as insignificant and below our notice, except the pursuit of knowledge and the cultivation of virtue; and giving a dignity and importance to the enjoyment of life, which the frivolous and the grovelling cannot even comprehend.

Let us, then, conclude, that the Pleasures of Science go hand in hand with the solid benefits derived from it; that they tend, unlike other gratifications, not only to make our lives more agreeable, but better; and that a rational being is bound, by every motive of interest and of duty, to direct his mind towards pursuits which are found to be the sure path of Virtue as well as of Happiness.-BROUGHAM.



1. Spontaneous Combustion. Q. Give an example of spontaneous combustion.

A. Coals stowed in the hold of a vessel, and goods packed in a warehouse, will often catch fire of themselves, -especially such goods as cotton, flax, hemp, rags, &c.

Q. Why do such goods sometimes catch fire of themselves?

A. Because they are piled together in very large masses in a damp state or place.

Q. Why does this produce spontaneous combustion ?
A. The damp produces decay, or the decomposition of the

1 From Brewer's Guide to the Scientific Krowledge of Things Familiar.

goods; and the great heat of the piled up mass makes the decaying goods ferinent.

Q. How does this fermentation produce combustion ?

A. During fermentation carbonic acid gas is given off by the goods,-a slow combustion ensues,-till at length the whole pile bursts into flame.

Q. Why is the heat of a large mass of goods greater than that of a smaller quantity ?

A. Because the carbonic acid cannot escape through the massive pile ; and the products of decomposition being confined, hasten further changes.

Q. Why do haystacks sometimes catch fire of themselves?

A. Either because the hay was got up damp; or else because rain has penetrated the stack.

Q. Why will a haystack catch fire if the hay be damp? A. Because damp hay soon decays, and undergoes a state of fermentation; during which carbonic acid gas is given off, and the stack catches fire.

Q. Roasted coffee sometimes catches fire spontaneously. Explain the reason of this.

Ā. The heat of coffee is greatly increased by being roasted; and the carbon of the coffee, uniting with the oxygen of the air, produces carbonic acid gas, and bursts into flame.

Q. Why do old rags, used for cleaning lamps and candlesticks, sometimes set a house on fire ?

A. Because they very readily, ferment, and (during fermentation) throw off exceedingly inflammable gases.

2. Charcoal.

Q. What is charcoal ?

A. Wood which has been exposed to a red heat till it has been deprived of all its gases and volatile parts.

Q. Why is a charcoal fire hotter than a wood fire ?

A. Because charcoal is very pure carbon, and as it is the carbon of fuel which produces the glowing heat of combustion, therefore the purer the carbon, the more intense will the heat of the fire be.

Q. Why does charcoal remove the taint of meat ?

A. Because it absorbs all putrescent effluvia, whether they arise from animal or vegetable matter.

Q. Why is water purified by being filtered through charcoal ?

A. Because charcoal absorbs the impurities of the water, and removes all disagreeable tastes and smells, whether they arise from animal or vegetable matter.

Q. Why are water and wine casks charred inside ?

A. Because charring the inside of a cask reduces it to a kind of charcoal; and charcoal (by absorbing animal and vegetable impurities) keeps the liquor sweet and good.

Q. Why does a piece of burnt bread make impure water fit to drink?

A. Because the surface of the bread (which has been reduced to charcoal by being burnt) absorbs the impurities of the water and makes it palatable.

Q. Why should toast and water, placed by the side of the sick, be made of burnt bread ?

A. Because the charcoal surface of the burnt bread prevents the water from being affected by the impurities of the sick room.

Q. Why should sick persons eat dry toast rather than bread and butter?

A. Because the charcoal surface of the dry toast helps to absorb the acids and impurities of a sick stomach.

There are other reasons, which belong to the science of Medicine.

Q. Why are timbers, which are to be exposed to damp, charred ?

A. Because charcoal undergoes no change by exposure to air and water ; in consequence of which timber will resist weather much longer after it has been charred.

3. Animal Heat.

Q. Does the heat of the human body arise from the same cause as the heat of fire ?

A. Yes, precisely. The carbon of the blood combines with the oxygen of the air inhaled, and produces carbonic acid gas, which is attended with combustion.

Q. If animal heat is produced by combustion, why does not the human body burn up like a coal or candle ?

A. It actually does so. Every muscle, nerve, and organ of the body actually wastes away like a burning candle; and (being reduced to air and ashes) is rejected from the system as useless.

Q. If every bone, muscle, nerve, and organ is thus con

sumed by combustion, why is not the body entirely consumed?

A. It would be so, unless the parts destroyed were perpetually renewed; but as a lamp will not go out so long as it is supplied with fresh oil, neither will the body be consumed so long as it is supplied with sufficient food.

Q. What is the principal difference between the combustion of a fire or lamp, and that of the human body?

A. In the human body the combustion is effected at a much lower temperature, and is carried on more slowly than it is in a lamp or fire.

Q. How is it that carbon can be made to burn at so low a temperature in the human body ?

A. Because the carbon in the blood is reduced to very minute particles; and these particles are ready to undergo a rapid change immediately oxygen is supplied.

Q. When a man is starved, what parts of the body go first?

A. First, the fat, because it is the most combustible; then the muscles; last of all the brain ; and then the man dies, like a candle which is burnt out.

Q. Why does want of sufficient nourishment often produce madness?

A. Because after the fat and muscles of the body have been consumed by animal combustion, the brain is next attacked ; and (unless the patient dies) madness ensues.

Q. Why does a man shrink when starved ?

A. Because the capillary fires feed upon the human body, when they are not supplied with food fuel. A starved man shrinks just as a fire does, when it is not supplied with fuel.

Q. What is the fuel of the body ?

A. Food is the fuel of the body. The carbon of the food, mixing with the oxygen of the air, evolves heat, in the same way that a fire or candle does.

Q. Why is every part of the body warm?

A. Because the capillary vessels run through every part of the human body, and the combustion of blood takes place in the capillary vessels.

Q. Why does running make us warm ?

A.Because we inhale air more rapidly when we run, and cause the blood to pass more rapidly through the lungs in contact with it. Running acts upon the capillary vessels, as a pair of bellows on a common fire.

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