EXPERIMENTS IN THE CHEMISTRY. 77 



the bag may be removed and attached to the hydrogen ap- 

 paratus to be filled. 



5O. I. In lieu of a small crucible, fill a common tobacco- 

 pipe with crystals of blue vitriol, and heat them over the 

 lamp or in a common fire until the water of crystallization is 

 expelled. Alum may be rendered anhydrous in the same 

 manner. 



56. i. Small paste-diamonds may be obtained of a jewel- 

 ler, to illustrate the forms of cutting the diamond. 



6O. i . Place a filtering paper in the glass funnel, and in it 

 a couple of ounces of bone-black or finely-powdered charcoal. 

 Filter through it water colored with ink, litmus, or any other 

 impurities. In pouring the liquid into the filter hold a glass 

 rod against the edge of the pouring vessel, so as to direct the 

 stream into the funnel. The funnel may be placed in the 

 nozzle of a bottle, but must not fit closely. A bit of wood or 

 a thread inserted between the stem of' the funnel and the 

 nozzle will leave an opening sufficient for the egress of the air. 



64. i. Break some marble into small bits ; place them care- 

 fully in the evolution-flask, and, inserting the cork and tube, 

 pour in HC1 slowly. The gas, on account of its weight, may 

 be passed directly into a bottle or jar. 



2. Lower a lighted candle into a jar of the gas, or, lowering 

 the candle into an empty jar, pour the gas into the jar, as if it 

 were water. Test the acid with litmus paper. 



3. Place a piece of lime as large as an egg in a pint of wa- 

 ter; let it stand overnight; pour off the clear liquid it is 

 lime-water. Place a little in a tumbler and breathe through it 

 by means of a tube, or pass a current of CO, from the evolu- 

 tion-flask until the liquid, at first milky, clears. 



4. Breathe through a tube into an empty bottle. Lower 

 into it a lighted candle it will be immediately extinguished. 

 Pour in some lime-water, shake it thoroughly and it will be- 

 come milky. 



5. Twist a wire around the neck of a small wide-mouthed 

 vial, to answer as a bucket. Lower it by the wire into a jar 

 of CO a , our ideal well foul with the gas. Raise it again, and 

 test for the CO, by means of a lighted match. The bucket 

 will be found to be full of the gas. 



