10 BULLETIN 803, U. S. DEPAKTMENT OF AGRICULTURE. 



nitrogen by the Gunning method, using 40 to 50 cc. of acid, 10 grams 

 of potassium sulphate, and a small crystal of copper sulphate. 



Ash. — Burn a 10-gram sample in a flat-bottomed platinum dish at 

 a moderate temperature. If necessary to get a clean ash, cool, moisten 

 with water, evaporate, and ignite again, repeating until the carbon 

 is gone. 



Alkalinity of ash. — Add 25 cc. of N/10 sulphuric acid to the ash in 

 the dish, heat under a watch glass for a few minutes, and titrate 

 back with N/10 caustic soda, using methyl orange. 



Salt-free ash. — In pickled olives, make the solution up to 100 cc, 

 filter, and titrate 25 cc. portions with N/10 silver nitrate and potas- 

 sium chromate indicator. Express as salt, and calculate salt-free ash. 



CHEMICAL ANALYSIS OF PITS. 



Determine moisture, ether extract, nitrogen, and ash. For mois- 

 ture dry 5 grams in a lead capsule, without sand, to constant weight 

 in the water oven, which requires from four to five hours. Extract 

 this residue with anhydrous ether in the Knorr apparatus. This is 

 completed in from six to eight hours. Use 5-gram portions for 

 nitrogen and ash determinations. Calculate the analysis back from 

 the air-dry basis to that of the original moist pits as removed from the 

 olives. 



