It frequently occurs that the blue litmus-paper becomes faded by exposure in the jars, but no danger is to be apprehended in consequence. If the litmus-paper has become reddened, but no fumes or pasty spots are observed, the blocks should be lifted out by the loose ends of the tape and placed on a perfectly clean, dry piece of blotting-paper. Then untie the tape and separate the blocks, being careful not to touch them with the fingers. (A perfectly clean, dry crash towel may be used in handling the blocks.) Remove the strips of litmus-paper, insert freshly moistened strips in their places and tie the tape as before. After an hour‘s interval examine the ends of the strips of litmus-paper. If they have become reddened, wet the blocks with the alkaline solution (p. 45), until they have increased 30% in weight and use them as wet gun-cotton. If the moistened litmus strips have not become reddened after one hour‘s exposure, replace the blocks in the jar, close it tight and replace it in its box. =Monthly Inspection.=—Even if no change is observed in the litmus-paper at the weekly inspections the test just described, with freshly moistened blue litmus-paper strips, is to be applied to all dry gun-cotton once each month and this constitutes the _monthly inspection_. If the test shows the gun-cotton to be acid, the gun-cotton should be wet with the alkaline solution (p. 45), until it has increased 30% in weight, and then used as wet gun-cotton. INSPECTION OF WET GUN-COTTON. =Quarterly Inspection.=—The wet gun-cotton is packed in the Service and Exercise cases and contains from 30% to 35% of water. The gross weight of gun-cotton and case is marked upon each case. These cases are to be separately weighed every three months and any loss in the gross weight made up by the addition of pure water poured through the filling-hole, which should then be carefully closed. PRECAUTIONS TO BE TAKEN IN INSPECTION. Do not handle the gun-cotton with the bare hand. Never touch litmus-paper with the bare hand. Blue litmus-paper may become reddened by the acid substances exuded from the skin. Litmus-paper should always be handled with the forceps provided in the Chemical Box. Always moisten the litmus-paper before making the test, using the distilled water provided in the Chemical Box. Hold the litmus-paper strip in the forceps, dip one of the glass rods, provided in the Chemical Box, in the bottle of distilled water and then apply the moist rod to the paper. The litmus-paper must be moist, only, and not reeking with water. Should the supply of water in the Chemical Box be exhausted, water distilled on board, or fresh rain water, may be used, provided it first be tested and found free from acid reaction.