Question: Account for the delicate shades of colour sometimes seen on the inside of an oyster shell. State and explain the appearance presented when a beam of light falls upon a sheet of glass on which very fine equi-distant parallel lines have been scratched very close to one another.
Answer: The delicate shades are due to putrefaction; the colours always show best when the oyster has been a bad one. Hence they are considered a defect and are called chromatic aberration.
The scratches on the glass will arrange themselves in rings round the light, as any one may see at night in a tram car.

Question: How would you disprove, experimentally, the assertion that white light passing through a piece of coloured glass acquires colour from the glass? What is it that really happens?
Answer: To disprove the assertion (so repeatedly made) that “white light passing through a piece of coloured glass acquires colour from the glass,” I would ask the gentleman to observe that the glass has just as much colour after the light has gone through it as it had before. That is what would really happen.

Question: On freezing water in a glass tube, the tube sometimes breaks. Why is this? An iceberg floats with 1,000,000 tons of ice above the water line. About how many tons are below the water line?
Answer: The water breaks the tube because of capallarity. The iceberg floats on the top because it is lighter, hence no tons are below the water line. Another reason is that an iceberg cannot exceed 1,000,000 tons in weight: hence if this much is above water, none is below. Ice is exceptional to all other bodies except bismuth. All other bodies have 1090 feet below the surface and 2 feet extra for every degree centigrade. If it were not for this, all fish would die, and the earth be held in an iron grip.
P.S.—When I say 1090 feet, I mean 1090 feet per second.

At length being at Clapham where there is, on the common, a large pond which, I observed to be one day very rough with the wind, I fetched out a cruet of oil and dropt a little of it on the water. I saw it spread itself with surprising swiftness upon the surface; but the effect of smoothing the waves was not produced; for I had applied it first on the leeward side of the pond, where the waves were largest, and the wind drove my oil back upon the shore. I then went to the windward side, where they began to form; and there the oil, though not more than a tea-spoonful, produced an instant calm over a space several yards square, which spread amazingly, and extended itself gradually till it reached the leeside, making all that quarter of the pond, perhaps half an acre, as smooth as a looking-glass.
[Experiment to test an observation made at sea in 1757, when he had seen the wake of a ship smoothed, explained by the captain as presumably due to cooks emptying greasy water in to the sea through the scuppers.]

But it must not be forgotten that ... glass and porcelain were manufactured, stuffs dyed and metals separated from their ores by mere empirical processes of art, and without the guidance of correct scientific principles.

Chemistry works with an enormous number of substances, but cares only for some few of their properties; it is an extensive science. Physics on the other hand works with rather few substances, such as mercury, water, alcohol, glass, air, but analyses the experimental results very thoroughly; it is an intensive science. Physical chemistry is the child of these two sciences; it has inherited the extensive character from chemistry. Upon this depends its all-embracing feature, which has attracted so great admiration. But on the other hand it has its profound quantitative character from the science of physics.

Chemistry... is like the maid occupied with daily civilisation; she is busy with fertilisers, medicines, glass, insecticides ... for she dispenses the recipes.

I took a glass retort, capable of containing eight ounces of water, and distilled fuming spirit of nitre according to the usual method. In the beginning the acid passed over red, then it became colourless, and lastly again all red: no sooner did this happen, than I took away the receiver; and tied to the mouth of the retort a bladder emptied of air, which I had moistened in its inside with milk of lime lac calcis, (i.e. lime-water, containing more quicklime than water can dissolve) to prevent its being corroded by the acid. Then I continued the distillation, and the bladder gradually expanded. Here-upon I left every thing to cool, tied up the bladder, and took it off from the mouth of the retort.— I filled a ten-ounce glass with this air and put a small burning candle into it; when immediately the candle burnt with a large flame, of so vivid a light that it dazzled the eyes. I mixed one part of this air with three parts of air, wherein fire would not burn; and this mixture afforded air, in every respect familiar to the common sort. Since this air is absolutely necessary for the generation of fire, and makes about one-third of our common air, I shall henceforth, for shortness sake call it empyreal air, [literally fire-air] the air which is unserviceable for the fiery phenomenon, and which makes abut two-thirds of common air, I shall for the future call foul air [literally corrupted air].

I went to the trash pile at Tuskegee Institute and started my laboratory with bottles, old fruit jars and any other thing I found I could use. ... [The early efforts were] worked out almost wholly on top of my flat topped writing desk and with teacups, glasses, bottles and reagents I made myself.

It has the property of detonating very violently in certain circumstances. On one occasion a small amount of ether solution of pyroglycerin condensed in a glass bowl. ... When the bowl was heated over a spirit lamp, an extremely violent explosion occurred, which shattered it into small fragments. On another occasion a drop was heated in a test-tube, and exploded with such violence that the glass splinters cut deep into my face and hands, and hurt other people who were standing some distance off in the room.
[Describing early experiments on his discovery of nitroglycerin.]

See, thro' this air, this ocean, and this earth,
All matter quick, and bursting into birth.
Above, how high progressive life may go!
Around, how wide! how deep extend below!
Vast chain of being, which from God began,
Natures ethereal, human, angel, man,
Beast, bird, fish, insect! what no eye can see,
No glass can reach! from Infinite to thee,
From thee to Nothing—On superior pow'rs
Were we to press, inferior might on ours:
Or in the full creation leave a void,
Where, one step broken, the great scale's destroy'd:
From Nature's chain whatever link you strike,
Tenth or ten thousandth, breaks the chain alike.

The glimpses of chemical industry's services to man afforded by this book could be presented only by utilizing innumerable chemical products. The first outline of its plan began to take shape on chemically produced notepaper with the aid of a chemically-treated graphite held in a synthetic resin pencil. Early corrections were made with erasers of chemically compounded rubber. In its ultimate haven on the shelves of your bookcase, it will rest on a coating of chemical varnish behind a pane of chemically produced glass. Nowhere has it been separated from that industry's products.

The One remains, the many change and pass;
Heaven's light forever shines, Earth's shadows fly;
Life, like a dome of many-coloured glass,
Stains the white radiance of Eternity,
Until Death tramples it to fragments.

We are now in the mountains and they are in us, kindling enthusiasm, making every nerve quiver, filling every pore and cell of us. Our flesh-and-bone tabernacle seems transparent as glass to the beauty about us, as if truly an inseparable part of it, thrilling with the air and trees, streams and rocks, in the waves of the sun,—a part of all nature, neither old nor young, sick nor well, but immortal.‎

We live in a glass-soaked civilization, but as for the bird in the Chinese proverb who finds it so difficult to discover air, the substance is almost invisible to us. To use a metaphor drawn from glass, it may be revealing for us to re-focus, to stop looking through glass, and let our eyes dwell on it for a moment to contemplate its wonder. [Co-author with Gerry Martin.]

When one longs for a drink, it seems as though one could drink a whole ocean—that is faith; but when one begins to drink, one can only drink altogether two glasses—that is science.

Why are atoms so small? ... Many examples have been devised to bring this fact home to an audience, none of them more impressive than the one used by Lord Kelvin: Suppose that you could mark the molecules in a glass of water, then pour the contents of the glass into the ocean and stir the latter thoroughly so as to distribute the marked molecules uniformly throughout the seven seas; if you then took a glass of water anywhere out of the ocean, you would find in it about a hundred of your marked molecules.