JOIIANN CARL LEUCIIS ON WINE-MAKING. 197 



ferent, according to the nature of the fluid. One that has more 

 particles in the same space will offer more resistance, and conse- 

 quently allow the body to sink less deeply. For instance, water 

 in which salt or sugar has been dissolved has, of course, more par- 

 ticles than pure water, and will consequently not allow the body 

 to sink so deep into it. 



Of this property of matter use has been made to determine the 

 proportion of solid parts in a given fluid, or the quantity of light- 

 er fluids mixed with it. An instrument for this purpose is called 

 an Areometer^ or, according to its various purposes, a Hydrome- 

 ter (Water-Scale), an Alcoholometer (Spirit-Scale), a Must-Scale, a 

 <S'acc/io?^o?72(?/'er (Sugar-Scale), an ^Zca/mieile?- (Alkali-Scale), etc., etc. 



The main parts of such an instrument are, a stem, with a hol- 

 low ball at its foot, to make it swim, with a weight beneath, to 

 keep it in a perpendicular position. The stem is divided into 

 equal parts (degrees), and determines by them the weight of the 

 fluid, or its contents of solid or spirit jDarts. The kinds named 

 after their inventors, Beaume's, Cartier's, Tralles's, Richter's, and 

 those for especial purposes, as for sugar, salt, malt liquor, are the 

 most in use. 



Of Beaume's Areometer we have two kinds : one for fluids that 

 are heavier than water, the other for lighter ones. In the former 

 kind, the point at which the stem sinks into pure water is marked 

 by 0, and the one at which it sinks into a solution of 10 parts of 

 salt in 85 parts of water by 15 ; the intervening space, therefore, is 

 divided into 15 parts, and the entire stem is likewise divided into 

 degrees of similar length. Each degree thus indicates 1 per cent. 

 of salt. In the latter kind, the point at which the stem stands in 

 pure water is marked by 10° ; the one at which it stands in a so- 

 lution of 10 parts of salt in 90 of water by ; and the entire stem, 

 up to its upper end, is divided into 60 and more equal degrees. 



Cartier's areometer differs but little from this latter. It sinks 

 in pure water to 10° ; in pure alcohol to 42°. The higher degrees 

 only differ somewhat. For instance, 14° C. are =13.47° B. ; 18° 

 C. =17.73° B. ; 25° C. =25.2° B. ; 30° C. =30.53° B. 



Eichter's alcoholometer sinks in water to ; in pure alcohol 

 to 100°. The number of degrees to which it sinks in a fluid com- 

 posed of water and alcohol indicates how many parts by weight 

 of alcohol of the specific gravity of 0.792 are contained in 100 

 parts by weight of the fluid to be tested. Thus, if in a distilled 

 malt liquor, the instrument sinks to 50°, it indicates that this con- 

 tains 50 parts of alcohol and 50 parts of water. 



Tralles's alcoholometer indicates the contents in the same man- 

 ner by measure. Whisky of 30° T. contains, therefore, in 100 

 parts, 30 parts of alcohol and 70 parts of water by measure. 



Beaume's areometer is the most in use. In order to weigh 

 fluids that are heavier than water, such as malt beer, sirup, sugar 

 solution, etc., 60°, measuring downward from 0, is usually taken 

 as the point at which it stands in pure water. 



