i6o 



AGRICULTURAL CHEMISTRY 



ture. Crude ash is obtained by burning a substance 



until all of the carbon is 

 oxidized. 



Experiment ^.Determina- 

 tion of ash. Weigh to the 

 second decimal place in grams, 

 a dish given out for this experi- 

 ment. Then weigh into the dish 

 about 2 grams of dry clover or 

 other hay, place in the muffle 

 furnace, and let it remain until 

 there is no charred material left. 

 Cool on an asbestos mat. Weigh 

 again and determine the per 

 cent, of ash from the material 

 taken and the weight of the ash 

 obtained. Calculate the per 

 cent, of organic matter. Save 

 the ash for future experiments. 

 [The 500, 200, and 100 mg. 

 weights are to be recorded as 

 0.5, 0.2, and o.i gram ; the 50, 



Fig. 67. Muffle furnace used for 

 determination of ash. 



20, and 10 mg. weights as 

 0.05, 0.02, and o.oi gram. 

 If one used a lo-gram 

 weight, a soo-mg. weight, 

 and a 2o-mg. weight, it 

 would be written 10.52 

 grams.] 



208. Form of the 

 Ash Elements. 



None of the elements 

 present in the ash of 

 plants ever exist there 



Fig. 68. Weights for balance. 



