68. Q. As what did his followers afterward become known, under Zinzendorf? A. As the United Brethren. 69. Q. What was the political effect of the Reformation? A. To elevate the people to a thirst for liberty, and a higher and purer citizenship. 70. Q. Of what did the Reformation become the mother? A. Of republics. 71. Q. To what does the American Union owe a large measure of its genesis? A. To the European struggle for reform. 72. Q. What was one of not the least benefits conferred upon the world by the Reformation? A. The promotion of learning. 73. Q. What sprang up throughout Germany, as an immediate fruit of the Reformation? A. Universities. 74. Q. By what celebration have the memories of the Reformation been recently renewed? A. By the celebration on November 11, 1883, of the four hundredth anniversary of the birth of Luther. 75. Q. How was the day observed? A. With becoming festivities in all the Protestant countries of the world. II.—TWENTY-FIVE QUESTIONS AND ANSWERS ON “CHEMISTRY,” FROM PAGE 157 TO THE END OF THE BOOK. 76. Q. What are some of the most important uses of borax? A. In the manufacture of porcelain, and in other of the industrial arts, and as a remedial agency in medicine. 77. Q. In addition to the well known substances sodium and oxygen, what element does borax contain? A. A special and peculiar element, called boron. 78. Q. What are two of the most important sources of borax? A. Borax Lake, in California, and the borax lagos in Tuscany. 79. Q. What element constitutes about eighty per cent. of our atmospheric air? A. Nitrogen. 80. Q. As a simple and uncombined substance, by what is nitrogen characterized? A. By extreme inactivity. It does not burn; it does not support combustion; it can not be made to enter into chemical union with other substances, except by specially devised and circuitous processes. 81. Q. Of what is nitrogen a constituent? A. Of a very large number of compounds, which are themselves often characterized by a high degree of activity. 82. Q. What are two important compounds of nitrogen? A. Ammonia gas and nitric acid. 83. Q. In addition to oxygen and nitrogen what are some of the other substances always present in atmospheric air? A. Vapor of water, carbon di-oxide, and ammonia gas; minute quantities of a vast multitude of other gaseous substances; and it is likewise charged most of the time with still more minute quantities of solid dust materials of various kinds. 84. Q. To what do the principal explosives owe their activity to a very large degree? A. To the presence of nitrogen in them. 85. Q. What are the four explosives of chief importance? A. Gunpowder, the fulminates, gun cotton, and nitro-glycerine. 86. Q. What are the three principal constituents of gunpowder? A. Potassic nitrate, charcoal, and sulphur.