xlii 



WEIGHTS AND MEASURES. 



In the new French measures, decreed in 1812, the pinte is to he the 

 same as the metrical litre, and the boisseau is to be 12 litres and a half, 

 equal to 7^ English cubic inches .35. 



Une verre a vin, ^viij 



Une verre d'un seul traite, 3V 



Une verre au liqueur, 3vj 



Une cuiller a bouche, ^v 



Une cuiller a cafe, 5-4ths of a dram 



Un seau, 481b., of 16 ounces. 



Un bassin, 41b. 



SPECIFIC GRAVITY. 



This is usually quoted in England by a reference to water as unity; 

 but the great convenience of Baume's hydrometer, and the ease with 

 which it may be constructed and graduated, have brought it into uni- 

 versal use on the continent. 



There are two of these liydrometers usually employed ; one for 

 liquids lighter than water, the other for those which are heavier. In 

 both of them the same fixed points are used, namely, the floating point 

 of the instrument in distilled water, or in a brine or solution of one 

 ounce of dry common salt in nine ounces of water. 



The correspondence between these hydrometers and the common 

 expression of specific gravity, as given by Drs. Brugmans, Driessen, 

 Vrolick, and Deiman, in the Pharmacopoeia Eatava, is here exhibited. 

 The temperature of the liquor being between 56 and 60 degrees of 

 Fahrenheit ; for as the hydrometers are at best but a mere approxima- 

 tion to the truth, it is needless to be more particular. 



In Baume's hydrometer for liquids lighter than water, the instru- 

 ment is poised, so that the of the scale is at the bottom of the stem, 

 when it is floating in the saline solution, and the depth to which it 

 sinks in distilled water shows the 10th degree ; the space between 

 these fixed points being equally divided. His graduation was conti- 

 nued upwards to the 50th degree, but should be now continued further. 



HYDROMETER FOR LIGHT FLUIDS, OR PESE-ESPRIT. 



