WATER CONTENT AND ASH OF PLANTS 159 



completing the process in the water-oven. When dry, weigh, and 

 from the loss of weight, calculate the per cent, of solids. Sp. gr. of 

 milk, 1.032. i cc. H 2 O = I gram, i cc. milk = 1.032 grams. If 

 skim milk is used, the sp. gr. is 1.035. 



Experiment 39. Water in clover. Weigh an aluminum dish. 

 Take three or four large clover plants and cut fine with shears or 

 knife. Weigh a portion in the dish ; dry, and weigh again as in 

 Experiment 36. Determine the per cent, of water in clover. 



Questions, (i) How did the potato, after drying, compare in 

 appearance and volume with the material before drying ? (2) How 

 does the percentage amount of water which you have obtained, 

 compare with the figures given in the tables of analysis. (3) In 

 the determination of water in milk, what was the appearance of the 

 milk solids? (4) What classes of compounds are present in milk 

 solids. (5) How does the amount of water obtained in Experi- 

 ment 37 compare with the amount given in the tables of analysis ? 

 (6) What would be the shrinkage in weight of a barrel of flour if 

 2 per cent, of moisture were removed, and what would be the in- 

 crease in weight if 2 per cent, of moisture were absorbed from the 

 air ? (7) How does the amount of water obtained in Experiment 39 

 compare with that obtained from the other materials? (8) How 

 much water is present in a ton of green clover ? 



207. Plant Ash. The ash of a plant, or of any ma- 

 terial, is that portion which remains after the substance 

 is burned at the lowest temperature necessary for com- 

 plete combustion. It is sometimes spoken of as the min- 

 eral or inorganic part, also as the uon- volatile part, and 

 includes all of the materials, with the exception of water 

 and nitrogen, which the plant takes from the soil during 

 growth. The term ash as used in chemistry differs from 

 the term as ordinarily used in that the chemical ash is 

 pure ash, free from unburned particles of carbon, and also 

 contains elements, as sodium, chlorin, sulfur and phos- 

 phorus, traces of which are volatile at a high tempera- 



