OF ARTS AND SCIENCES. 37 



140° to 150° in a current of air ; the air being first caused to pass 

 tlirough a series of six tubes, each 2. J feet long; two being filled with 

 solid potassic hydrate, and the remaining four with calcic chloride. 

 The substance being weigiied before and after heating, the water was 

 estimated by the loss of weight. The bases were then estimated in the 

 anhydrous salts by the methods given below. 



Dipotassic methylurate, K2CJI(CH3)N^03 . 311^0. 



This salt was made by suspending about one gramme of the acid 

 in ten or fifteen cubic centimetres of boiling water in a small flask, 

 and then adding a solution of potassic hydrate in large excess over the 

 amount necessary to dissolve the acid. The solution was then boiled 

 for some time, and about 100 cc. of alcohol added. On the addition 

 of tlie alcohol, the salt separates out in a flocculent form. The flask is 

 then corked up, to avoid exposure to carbonic acid, and allowed to 

 stand twenty-four hours. The precipitate is then filtered off rapidly 

 by the Bunsen pump, washed with alcohol, and dried in vacuo over 

 sulphuric acid and potassic hydrate. 



This salt when dry is an amorphous flocculent substance, and is 

 very soluble in hot water; but when a hot solution cools, the salt does 

 not separate out, but becomes a gelatinous mass resembling glue. This 

 salt absorbs carbonic acid very readily from the air. When carbonic 

 acid is passed tlu-ough a solution of this salt, the monopotassic salt is 

 probably formed, though no precipitate falls. 



The water of crystallization was determined by the method given 

 above. For the determination of the potassium, the anhydrous salt 

 was ignited in a platinum crucible ; and, after the residue had been 

 burned as white as possible, it was treated with a few drops of hydro- 

 chloric acid. The excess of hydrochloric acid was then driven off, and 

 the crucible ignited gently to avoid decrepitation, and then finally 

 heated to dull redness for a few seconds. 



0.3700 grm. of salt dried in vacuo gave 0.0635 grm. lip = 17.17 % 

 Calculated for K^C^HCCiyN.Og . 311,0 = 17.29 % 



0.4974 grm. of dried salt gave 0.2367 grm. KCl; K = 24.95 % 



Calculated for K,C5H(CH3)N,03 = 25.04 % 



Monopotassic methylurate, KCgTT2(CIl3)NP3 . 1\0. 



This salt was made by suspending about one gramme of the acid in 

 ten or fifteen centimetres of boiling water, and adding potassic carbon- 



