98 Morey on Miatrai Waters^ ^c. 



tion of the puh^erized marble. The best mode I have 

 tried as yet, is to cause the vessel to revolve, say a stone 

 jug, on an axis and end over end : and to have a portion of 

 the marble coarse. As the sulphate of lime forms on the 

 surface of these lumps, by their friction in rolling over each 

 other, it appears to be worn off, presenting continually fresh 

 surface for the acid to act upon, and thereby continuing ve- 

 ry regularly, its operation ever so long. These vessels may 

 be made to revolve (very slowly if necessary) by weights, 

 springs, or a part of the water — or may occasionally be 

 moved by hand. The gas presses out at one end of this 

 axis. A very cheap, quick, and agreeable mode of pre- 

 paring the water, where we have (or have not) an aqueduct 

 or head to resort to, is to take four or five, or more decan- 

 ters, say of the capacity of a quart ; fill them with fragments 

 of marble — set them in a row or other form, each with a 

 good cork ; let a tin tube screw upon the axis to receive 

 the gas, and press pieces of cork or other stuffing to the 

 vessel, to make it tight around the axis. This tube, near 

 the othev end, is of a conical form, and turned down at a 

 right angle far enough to be inserted through the cork of 

 the first bottle: another tube, turned down at each end, so 

 that one leg shall pass through the cork also, to the bottom 

 of the first decanter, and the other through the cork of the 

 second decanter ; and so on with as many as are to be used. 

 A small reservoir is to be placed as many feet above as 

 convenient, and the first vessel, with a small pipe leading 

 down and through the first cork, with an opening at the 

 lower end about one-thirtieth of an inch in diameter. A 

 quantity of pulverized lime and water may be put into the 

 revolving vessel ; then more water, containing a small quan- 

 tity of clay or sulphate of lime. This will be deposited on 

 the lime, so as to prevent the action of the acid when pour- 

 ed in, which may now be added, and this vessel corked. 

 It is now ready for use. Put cool water into the reservoir, 

 turn the vessel moderately a very little, if the gas is not al- 

 ready forming fast enough. The water strikes on the first 

 fragments of stone, »s thrown over them, and passes over 

 the surface, from one to another, to the bottom, where it is 

 continually taken up by the tube with a portion of the gas, 

 and discharged just below the cork of the second vessel ; 

 or thrown out in a spray by and with the gas ; or else dis- 



