On I he Alkalies of Commerce, 1 75 



nierce, at QQ degrees of Baume's areometer; afterwards 

 put in equilibrium, in a good balance, a vessel of porcelain 

 or glass, and pour into it a given weight of the above acid, 

 say a hectogramme; add carefully, on account of the caloric 

 which is liberated, nine hectogrammes of pure water, then 

 stir it well with a glass rod ; and then put it into a bottle, 

 which you must cork up; that no alteration, either by 

 dust or by evaporation, may take place. 



Graduatlo7i of the Alkali-meter. 

 The alkali-meter is then graduated by given weights of 

 this liquor in the following manner : Place the instrument 

 in perfect equilibrium in a balance, and introduce into it 

 very exactly two grammes or four denii-gTammes of the test 

 liquor; place the tube afterwards in a vertical position, 

 and mark the level by a small scratch with a diamond ; pour 

 in once more, and all at one time, 36 grammes or 62 derai- 

 grammes of the liquor, and mark this level also bv a scratch : 

 after this, empty the instrument, and draw a mark on the 

 other four vertical parallel lines ; and forming three spaces 

 of about one line between each, mark on the two eactre- 

 mities two small transverse lines, making right angles with' 

 the other four; then write in the upper part, and 75 in 

 the lower; pour liquor into the tube afterwards, up to the 

 point marked 72 ; put the instrument once more in equili- 

 brium, and introduce one after the other 71 demi-grammes 

 of the test liquor, taking care to mark, each time, one point 

 in the middle scale : this bcino; accomplished, trace regularly, 

 by four and four points, lines across the three scales ; then 

 trace in the same manner, upon all the other points, lirxs 

 through the middle scale only : engrave, after this, on one sicle^. 

 and opposite to each fourth division, the cyphers 4. 8. 12. 

 16. 20, 24. 28. 32. 30. 40. 44. 48. 52. 5Q. 60. 04. 68. and 

 72 : the engraved figure of the alkali-nieter will rendcj this 

 description more intelligible. 



I shall, by and by, inform my readers how and wherefore 

 I arranged this instrument so as, if necessary, to supply the 

 place of the Bcrtholii-ioeter. The marks are made with 

 very little trouble by employing a glazier's diamond. 



Alkali' 



