Nor did they yield their theory when Lavoisier claimed to disprove it by burning phosphorus in oxygen and weighing the result, which was heavier than the phosphorus had been. Thereupon the world derided the alchemists and lauded Lavoisier whose experiments laid the foundation for the intricate science of modern chemistry. For all that, science gives us the truth only from one angle and the science of one age is often disproved by the science of the next. Modern chemists may agree on what happens when phosphorus burns, but many a theory of Lavoisier's day has been disproved in its turn. A thousand scientists have declared flying impossible to man, yet today men fly. Lavoisier was right, no doubt. Combustion is the combination of an element with oxygen. He proved that with his chemist's balance. Yet how did he prove that some imponderable element does not leap from wood in flame? As well say that when a man dies the spirit has not left the body because he weighs the same. Watching the falling embers of the Yule log leap into flames before they turn gray, I am apt to think that the intuition of the alchemists touched a truth that the chemical apparatus missed. You cannot measure its reaction on the mind of man or weigh the results, but they are there. ***** Wood was the sole fuel of the New England pioneers for two centuries. In fact in many a remote farmhouse it is today, and the fathers soon found by use which kind lighted quickest and which burned longest and with the most steady heat, facts which the subtle analysis of the chemists only confirmed. The conifers light most readily and burn rapidly with the greatest heat in a given time. The hard woods burn longest, some of them retaining fire for a surprising length of time under just the right conditions. The woodsmen will tell you that the pines light easily and burn fiercely because of the pitch they contain. This is true but the chemists have added another reason. Pine gives off much hydrogen when heated and this light and inflammable gas gives much flame. Even in pine wood which does not seem resinous to the touch there is much of this volatile inflammable material and a good store of pine kindlings is a first requisite in every well ordered country household. Of the hard woods hickory is easily king as a fire holder. Yet the oaks, white and red, and the sugar and black maples are not far behind in value. Our American white ash and elm rank well up with the oaks, so does beech, while the softer woods fall behind. Moreover, trees grown on high, droughty, barren soil show greater heating power than those of the same variety which happen to stand in rich, but moister soil.