(1.) Three c.c. of a solution containing 9.61 per cent. acetone gave 1.7850 grm. KBr. Acetone found = 9.66 per cent. (2.) Ten c.c. of a solution containing 0.96 per cent. acetone gave 0.5847 grm. KBr. Acetone found = 0.95 per cent. ~Nitro-Cotton.~--The first thing upon opening a case of wet cotton, or in receiving a sample from the "poacher," that requires to be determined is the percentage of water that it contains. It is best done by weighing out about 1,000 grms. upon a paper tray, which has been previously dried in the oven at 100 deg. C. for some time, and become constant in weight. The trayful of cotton is then placed in a water oven, kept at 100 deg. C., and dried as long as it loses water. The loss gives the percentage of water. It varies from 20 to 30 per cent. as a rule in "wet" cotton. OUTLINE SCHEME FOR THE ANALYSIS OF NITRO-EXPLOSIVES _______________________________________________________________________ | | | Exhaust dried substance with Anhydrous Ether in Soxhlet's Fat | | Extraction Apparatus. | |_______________________________________________________________________| | | | _Solution_--Divide into two parts ~A.~ and ~B.~ | |_______________________________________________________________________| | | | ~A.~ | | | | Allow ether to evaporate spontaneously. Dry residue in vacuo over | | H_{2}SO_{4} and weigh. Equals nitro-glycerine, resin, camphor, and | | paraffin. | | | | The nitro-glycerine in this residue may be decomposed by heating | | with a solution of alcoholic potash. Water may then be added, and the | | alcohol evaporated off on the water bath. From this solution the | | resin may be precipitated by HCl, filtered off, dried, and weighed. | | Solution containing the paraffin is treated with AmS solution and | | heated. On cooling the paraffin separates, and may be separated. | | Residue may be shaken with CS_{2} to remove camphor. | |_______________________________________________________________________| | | | ~B.~ | | | | Add phenol-phthalein and titrate with alcoholic potash, 1 c.c. normal | | KHO = .330 grm. _resin_, and add considerably more KHO. Evaporate, | | dissolve residue in water, shake with ether, and separate.