CHEMICAL EXAMINATION OF RAW MATERIALS. 203 



one end of the ring entering it somewhat higher than the other. 

 On filling the cup with the fluid to be examined this hollow ring 

 also becomes filled. On the one side the ring carries -a small 

 sheet-iron chimney, and by placing a small spirit-lamp under this 

 the fluid in the cup is heated, this arrangement securing a quick 

 circulation of the fluid during heating. Upon the upper edge 

 of the cup, a lid is screwed, in which a thermometer is inserted 

 air-tight. The mercury bulb of the thermometer is on the lower 

 side of the lid, and in determining the boiling point dips into the 

 fluid. The tube of the thermometer is bent at a right angle out- 

 side the lid, the latter carrying the scale, which is divided not 

 into degrees but in per cent, by volume of alcohol. The scale 

 can be shifted upon a supporting plate so that it can be fixed at 

 any desired place, and, consequently, also so that the thermometer 

 when dipped into boiling water indicates 0. The scale is secured 

 by small screws. Into a second aperture in the lid is screwed the 

 cooling pipe which is surrounded by a wide-brass tube for the 

 reception of the cooling water. During the determination of the 

 alcohol, which requires about ten minutes, the cooling water need 

 not be renewed, the boiling point remaining constant during the 

 short time (one to two minutes) necessary for making the obser- 

 vation. In heating wine the gases and besides a few light 

 volatile varieties of ether, as acetic ether, aldehyde, ethylamine, 

 propylamine, and similar combinations escape through the cooling 

 pipe which is open on top, and in heating beer, carbonic acid. 

 For the determination of the alcohol in sacchariferous wines, the 

 ebullioscope is less adapted, nor does it give accurate results with 

 the use of dilute wines. 



It has been ascertained by the French Academy that the state- 

 ments of the ebullioscope as regards the quantity of alcohol in 

 the wine differ on an average ^ per cent, from those found by 

 accurate distillation. The entire apparatus with the exception of 

 the thermometer being of metal, it is not liable to breakage. 

 The mercury bulb of the thermometer is comparatively large. 

 For the vinegar manufacturer the ebullioscope is a very valu- 

 able instrument, as it enables him to accurately determine to with- 

 in 1 per cent, the content of alcohol in a fluid in a shorter time 

 than is possible with any other instrument. Its use is especially 



