484 SORGHUM. 



Specific gravity 1 050S 10600 



Per cent sucrose 9.726 9.710 



Per cent glucose 2 252 2 244 



Per cent solids not sugar 2 627 2 625 



Per cent polarization 10 281 10.244 



These results are practically identical. 



In like manner, during 1881, thei-e were made 72 analyses in du- 

 plicate ; and, as will be seen by consulting the tables giving the 

 results, tlie agreement was as close as could be expected with work of 

 this character. 



SPECIFIC GRAVITY. 



By specific gravity is meant the relative weight of any substance, 

 solid, liquid, or gaseous, as compared with water (which is taken as 

 the standard for solids and liquids), eras compared with air (which is 

 taken as the standard for gases). 



In the case of liquids, the determination of the specific gravity is 

 easy, and may be found by first filling a bottle (the weight of which is 

 known) with pure Avater, as rain-water, then finding the amount of 

 Avater, by weight, which the bottle will hold. By then filling the same 

 bottle with the liquid, the specific gravity of which it is desired to 

 know (as, sorghum juice), and weighing it, we may learn the weight 

 of a certain volume of the liquid, and also the weight of an equal 

 volume of pure water. If, now, we divide the weight of the sorghum 

 juice by the weight of the water, we ascertain the specific gravity 

 of the juice. 



For convenience, it is customary to use bottles which hold a certain 

 definite weight of pure water, as 100 or 1,000 grams, and then it is 

 only necessary to weigh the bottle full of juice, and the specific gravity 

 is at once shown by the weight. 



Such bottles are kn(^wn as piknometers ; but they are unnecessary. 

 The only precaution to be taken in the determination of the specific 

 gravity of sorghum juices is, that they should be allowed to stand a 

 sufficient length of time (from one-half an hour to an hour) after they 

 have been expressed by the mill, to allow the small bubbles of air 

 present to escape, since these would, of course, diminish the specific 

 gravity of the juice. 



Hydrometers and Saccharometers. 



Another method for readily determining the specific gravity of 

 liquids is by means of the hydrometer or saccharometer, of which 

 there are several kinds. 



