This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 edition. Excerpt: ... CHAPTER IX CAN ANYTHING BURN AWAY TO NOTHING? SOME boys and girls may be a little surprised to find in this book on Chemistry a chapter about the burning of things. What has burning to do with Chemistry? The burning is really due to chemical change taking place in the substances, as we shall see. Can ...
Read More
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 edition. Excerpt: ... CHAPTER IX CAN ANYTHING BURN AWAY TO NOTHING? SOME boys and girls may be a little surprised to find in this book on Chemistry a chapter about the burning of things. What has burning to do with Chemistry? The burning is really due to chemical change taking place in the substances, as we shall see. Can anything burn away to nothing? One little girl of ten years of age tells me that red candles do burn away to nothing, and I am not surprised, as only last night she saw ten red candles on her birthday cake burn away till all that was left was a very tiny piece of redhot wick, to show where each candle had been. Of course, it made no difference whether the candles were red, or blue, or green, but it did make a difference what kind of wax was in these candles. Suppose we make some experiments. First of all, we take one of the candles and we fix it on one pan of a pair of balance scales, just as shown in Fig. 17. We put a weight on the other pan so that the scales are balanced exactly as shown. You see how the little pointer at the top is pointing straight up. Fig. 17.--Weighing Ja Candle. We-place a. candle on one pan of the scales, and on the other pan we place a weight exactly equal to the candle. You see that they balance each other, as the pointer on the top is standing straight up. If you look at Fig. 18, you will see what happens when the candle burns. We set the candle alight, and we watch the scales. As the candle burns away we see that it becomes lighter. For we notice that the other pan with the weight on it sinks down, while the pan on which the candle rests rises up. This is just as we should expect, for half a candle cannot weigh as much as a whole candle. One very little friend interrupts me to ask what makes the scales move. We...
Read Less