512 XIV. APPARATUS AND CHESTS. 



Tracing paper. Nut oil, oil of turpentine, of each half a pint ; 

 rub the paper with this oil, and dry it immediately by rubbing it 

 with wheat flour ; this may be used to copy drawings or writings 

 as soon as made ; if washed over with ox gall it will bear being 

 written upon with ink. 



Storm glass, Camphire 5ij, saltpetre 5jss, sal ammoniac 5ss, 

 S. V. R. 3ij ; dissolve, keep in a bottle or tube covered with a 

 bladder : used to foretell changes of weather. 



Lead tree. Sugar of lead ^vj, distilled or rain water 2 pints; 

 dissolve, and hang in it, by a thread, a small piece of zinc. 



Tin tree. Muriate of tin 5iij, nitric acid 10 drops, distilled 

 water about 2 pints ; mix, and hang in it a small piece of zinc. 



Phosphorus bottles. Phosphorus 5ij, lime 5j, mixed together, put 

 into a loosely stopped phial, and heat it before the fire, or in a 

 ladle of sand, for about half an hour. — 2. Phosphorus 5j, cera alba 

 gr. XV, put it into a bottle under water, and melt them together, 

 let the water cool, and as it begins to grow solid, turn the bottle 

 round, that the sides may be coated, then pour out the water, and 

 dry it in a cool place. 



Matches for instantaneous light. Oxymuriate of potash, flowers 

 of sulphur, of each 3ss, vermilion gr. ij, oil of turpentine q. s. to 

 make a paste, with which coat the ends of slips of wood, previously 

 dipped in oil of turpentine and dried ; when these matches are 

 plunged into oil of vitriol and immediately withdrawn, they take 

 fire instantaneously. To prevent the oil of vitriol from spilling, if 

 the bottle should accidentally fall on one side, pounded asbestos or 

 sand is put into the bottle to soak up the acid. 



2. Oxymuriate of potash gr. ix, sugar gr. iij, flowers of sulphur 

 gr. ij, vermilion gr. j, wheat flour gr. ij, spirit of wine q. s. ; the 

 wood to be previously primed with camphire dissolved in spirit of 

 wine. 



Glue wafers f Medallion wafers. Colour Salisbury glue by means 

 of Brasil wood, turmeric, or the like : fill up the hollow part of a 

 seal with gum water mixed with any coloured powder, leaving 

 the flat part clear ; then pour as much of the melted coloured 

 glue on the seal as will lie upon it, and let it dry in a gentle heat ; 

 when used, wet the paper where the wafer is to be applied, 'and 

 place the back of the wafer upon the wet paper. 



Waxed paper. Cartridge paper placed on a hot plate, and 

 rubbed with bees'* wax : used to form steam pipes, gas pipes, or to 

 close the joining of vessels by merely wrapping a shp of it round 

 them, and tying it down with twine. 



