CONTRIBUTION TO STUDY OF HYDROXYLAMINE. — MACKAY. 327 



in a distilling- Hask titted ^vith a thermometer ^vith its bulb 

 dipping into the salt. An air condenser about 400nim. long 

 and 10mm. in diameter with about 50mm. of smaller glass 

 tubing joined on to the end, which passed through a rubber 

 cork into a wide mouthed bottle of 250cc. capacity, was attached 

 to the flask. Through another hole in the cork there passed a 

 glass tube to which the exhaust apparatus was connected. 



As it was necessary to weigh the pure h3Tlrox3damine, a 

 small tared weighing bottle was placed in the receiver immedi- 

 ately under the condenser so that it would collect most of the 

 hydroxylamine. 



The apparatus was exhausted by means of a " Geryk " 

 vacuum pump, a U tube filled with pumice stone soaked in 

 sulphuric acid followed by a calcium chloride tower filled with 

 fused sodium hydroxide and finally by a tower lying on its side 

 spread with phosphorus pentoxide, being placed between the 

 receiver and the pump in order to prevent access of hydroxy- 

 lamine, sulphuric acid or wacer vapor to the oil valves. A mer- 

 cury manometer was connected in parallel with the drying tubes. 



After the apparatus was exhausted to 6 or 8mm. pressure, 

 heat was gradually applied to the flask, hydroxylamine passing 

 slowly ott" until a temperature between 115° and 125° was 

 attained, when, under the same pressure, the greater quantity 

 of the hydroxylamine was expelled. Distillation was stopped 

 when the thermometer rose to 140° as it was desirous to obtain 

 as pure a product as possible, although Uhlenhuth allows the 

 temperature to rise to 170° with the pressure as high as 

 40mm. 



The hydroxylamine, of wdiich about 4 grams would be 

 obtained from 20 grams of phosphate, would condense in the 

 w^eighing tube, and when jarred or cooled would form perfectly 

 clear crystals, thus showing itself to be practically pure. There 

 was generally, however, a slight odor of ammonia notice- 

 able. 



