A Course of Six Lectures on the Chemical History of a Candle: To which is Added a Lecture on Platinum (Google eBook)

Front Cover
Harper & Brothers, 1861 - Candles - 208 pages
0 Reviews
  

What people are saying - Write a review

We haven't found any reviews in the usual places.

Common terms and phrases

Popular passages

Page 12 - George* it is said, by Colonel Pasley. It has been sunk in the sea for many years, subject to the action of salt water. It shows you how well candles may be preserved; for though it is cracked about and broken a good deal, yet, when lighted, it goes on burning regularly, and the tallow resumes its natural condition as soon as it is fused. Mr. Field, of Lambeth, has supplied me abundantly with beautiful illustrations of the candle and its materials. I shall therefore now refer to them. And, first,...
Page 37 - I suppose some here will have made for themselves the experiment I am going to show you. Am I right in supposing that any body here has played at snapdragon? I do not know a more beautiful illustration of the philosophy of flame, as to a certain part of its history, than the game of snapdragon. First, here is the dish; and let me say, that when you play snapdragon properly you ought to have the dish well warmed; you ought also to have warm plums, and warm brandy, which, however, I have not got. When...
Page 128 - ... there was plenty of air, but which was thrown off in excess when there was not oxygen enough to burn it. I have also to show you a little more distinctly the history of carbon and oxygen, in their union to make carbonic acid. You are now better able to understand this than before, and I have prepared three or four experiments by way of illustration. This jar is filled with oxygen, and here is some carbon which has been placed in a crucible, for the purpose of being made red-hot. I keep my jar...
Page 81 - ... that if I were to send steam through that barrel it would be condensed, supposing the barrel were cold; it is therefore heated to perform the experiment I am now about to show you. I am going to send the steam through the barrel in small quantities, and you shall judge for yourselves, when you see it issue from the other end, whether it still remains steam. Steam is condensible into water, and when you lower the temperature of steam you convert it back into fluid water; but I have lowered the...
Page 23 - It is by what is called capillary attraction that the fuel is conveyed to the part where combustion goes on, and is deposited there, not in a careless way, but very beautifully in the very midst of the centre of action, which takes place around it. Now I am going to give you one or two instances of capillary attraction. It is that kind of action or attraction which makes two things that do not dissolve in each other still hold together. When you wash your hands, you wet them thoroughly; you take...
Page 45 - I make the experiment) and you will find that it is burnt in two places, and that it is not burnt, or very little so, in the middle ; and when you have tried the experiment once or twice, so as to make it nicely, you will be very interested to see where the heat is, and to find that it is where the air and the fuel come together. This is most important for us as we proceed with our subject. Air is absolutely necessary for combustion ; and, what is more, I must have you understand that fresh air...
Page 121 - I have tied over this jar a piece of sheet Indiarubber, and I am now about to take away the air from the inside of the jar; and if you will watch the India-rubber which acts as a partition between the air below and the air above you will see, when I pump, how the pressure shows itself. See where it is going to : I can actually put my hand into the jar; and yet this result is only caused by the great and powerful action of the air above. How beautifully it shows this curious circumstance !...
Page 123 - ... if we take the pressure off, you will see how it will then go on expanding and expanding, larger and larger, until it will fill the whole of this bell-jar, showing you that wonderful property of the air, its elasticity, its compressibility, and expansibility, to an exceedingly large extent, and which is very essential for the purposes and services it performs in the economy of creation. We will now turn to another very important part of our subject, remembering that we have examined the candle...
Page 55 - The heat that is in the flame of a candle decomposes the vapor of the wax, and sets free the carbon particles; they rise up heated and glowing as this now glows, and then enter into the air. But the particles, when burnt, never pass off from a candle in the form of carbon. They go off into the air as a perfectly invisible substance, about which we shall know hereafter. Is it not beautiful to think that such a process is going on, and that such a dirty thing as charcoal can become so incandescent?...
Page 69 - ... it goes through its Protean changes, is entirely and absolutely the same thing, whether it is produced from a candle, by combustion, or from the rivers or ocean. First of all, water, when at the coldest, is ice. Now we philosophers I hope that I may class you and myself together in this case speak of water as water, whether it be in its solid, or liquid, or gaseous state we speak of it chemically as water. Water is a thing compounded of two substances, one of which we have derived...

Bibliographic information