The Analysis of Black Powder and Dynamite (Paperback)

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. 1916 edition. Excerpt: ...of nitroglycerin is that introduced by losses due to volatilization of the nitroglycerin during the evaporation of the ether. To determine the effect of the rapidity of evaporation on the amount of nitroglycerin lost, weighed samples (0.6 to 0.7 gram) of nitroglycerin were placed in 100 c. c. beakers, tieated with 50 c. c. of ether, the ether evaporated at different rates, and the samples dried in vacuum desiccators to remove the moisture taken up during the evaporation of the ether. Nitrogen was then determined by means of the nitrometer, the weight of nitroglycerin being calculated from the nitrometer reading. The results obtained are tabulated below: Loss of nitroglycerin on evaporating ether extract. "Weight of nitroglycerin=nitrometer reading+18.50. 'Loss of weight. No attempt was made to obtain constant weight after evaporation of the ether, the samples being left in vacuum desiccators only long enough to remove most of the water; hence the weights in column 3 are greater than the weights of nitroglycerin calculated from the nitrogen found (column 5). The figures in column 6 represent the differences between the weights in columns 2 and 5. It was noted that rapid removal of the ether, either by means of gentle heating or by means of an air current, caused a greater loss of nitroglycerin than did slow spontaneous evaporation at room temperature, the only exception being in the case of sample 5, with which the loss of nitroglycerin was only 0.0039 gram, the ether being volatilized by gentle boding. The large loss noted with sample 4 was probably due to spurting. Such losses as are shown in the table do not greatly affect the determination of nitroglycerin in a sample of dynamite. Thus, in analyzing a 6-gram sample of dynamite, a...