AMOUNT OF ALCOHOL IN WINE. 147 



proportion to the quantity of alcohol. A thermometer 

 tube is made use of, filled with quicksilver in such a 

 manner as to show all the varieties of temperature be- 

 tween boiling water and a boiling mixture of 75 parts 

 water and 25 parts absolute alcohol. Then let the fol- 

 lowing mixtures be made 95 parts water and 5 parts 

 alcohol ; 90 water and 10 alcohol ; 85 water and 15 

 alcohol; 80 water and 20 alcohol; 75 water and 25 

 alcohol Let water be boiled in a copper vessel at a 

 pressure of 760 millimeters (29*9 inches), and the 

 above-mentioned thermometer tube be placed in it, 

 and the part to which the extreme point of the column 

 of quicksilver reaches must be marked O. The ther- 

 mometer tube being again placed in the vessel, the 

 mixture of 95 parts water and 5 parts alcohol must then 

 be boiled, and the end of the column of quicksilver then 

 be marked with 5. The same process must be repeated 

 with the mixture of 90 parts water and 10 alcohol, 

 and the tube marked 10; 15 at the point to which 

 the quicksilver mounts in a boiling mixture of 85 

 parts water and 15 alcohol ; 20 in that of 80 parts 

 water and 20 alcohol, and 25 in 75 parts water and 25 

 alcohol. The space between 0, 5, 10, 15, 20, 25 may be 

 equally divided. The scale upon which the degrees 

 are marked, must be connected with the tube in such a 

 manner as to be moveable, and capable of being turned 

 by a screw in either direction, so that in every ex- 

 periment where the atmospheric pressure is different, 

 the thermometer may be first dipped in boiling water, 



