TRANSACTIONS OF SECTION B. 607 



melting at 33°; it is of a high specific gravity (1"35), without odour, hygroscopic 

 and volatile. 



The reason why the free hydroxylamine must he distilled at a low pressure is 

 that the suhstance is pretty violently explosive, and that explosion occurs sponta- 

 neously at the temperature of 130°. Thus care must be taken never to heat the 

 substance too strongly, for if heated at the ordinary pressure to 70° or 80°, an 

 explosion may occur, the spontaneous decomposition raising the temperature. The 

 hydroxylamine is an endothermous compound, and can be transformed totally into 

 gaseous products, the two conditions which, as is known, characterise an explosive. 

 I have produced an explosion in the following manner : 1 or 1-5 c.c. of the melted 

 base were put into an ordinary open test-tube, with a thermometer in it ; the tube 

 stood in an ordinary beaker, which, heated by a burner, acted as an air-bath. 

 "When the temperature had reached 90°, the flame was withdrawn ; the spontaneous 

 decomposition was vigorous and the temperature rose to 130.° Then a violent 

 explosion took place, the glass apparatus was reduced to powder, the copper-gauze 

 on which the vessel stood was torn to pieces, phenomena which prove that the 

 explosion is of the same nature as that of high explosives. If one drop of the 

 melted base in a tube is brought into a flame, a loud explosion is heard. 



The free base can burn in the air with a feeble yellowish flame. 



That hydroxylamine is a highly reducing agent is known since Lossen, about 

 thirty years ago, discovered the salts of the base. It is obvious that the free base 

 must show reducing properties in a much higher degree. On exposure to the air 

 at the ordinary temperature it gradually attracts oxygen ; one of the products of 

 the oxidation "is nitrous acid. When the free surface in contact with the air is 

 extensive the oxidation is accompanied by a rise of temperature — for instance, when 

 some filter paper or asbestos is moistened with the melted substance. A current 

 of oxygen passing over the substance gives rise to the formation of fumes containing 

 nitrous acid, the temperature rising at the same time. 



It is not surprising that oxidising agents act violently with the free base ; thus, 

 for instance, the solid permanganate of potassium, chromic acid, and some peroxides, 

 in contact with some drops of the substance, produce inflammation. Powdered 

 bichromate of potassium causes a sharp detonation ; solid iodate of sodium and 

 nitrate of silver are also reduced instantaneously. The action of anhydrous sul- 

 phate of copper is also very violent ; the reduction of the salt may be accompanied 

 by inflammation. 



Metallic sodium also acts violently, producing a flame. If the action is 

 moderated by adding some dry ether, hydrogen is evolved and a white substance, 

 NaONH2, is formed. This compound is a dangerous one because it explodes by 

 contact with the air. 



The halogen acts vehemently with the free base ; chlorine inflames it ; bromine 

 and iodine disappear immediately, producing the corresponding acids, water, and 

 nitrous oxide. 



As to the solvent properties of the free base, these are nearly equal to those of 

 water. It dissolves different salts, some of them, as for instance KI, in great quantity. 

 Gaseous ammonia, introduced at 16° into the melted base, is dissolved rapidly and 

 gives a solution containing 20 per cent, of the gas. 



In the same way the substance behaves like water with respec to other 

 liquids ; it is consequently only easily soluble in the alcohols and nearly insoluble 

 in the ordinary organic liquids. Methyl and ethyl alcohol are miscible with the 

 melted base in every proportion ; these solutions, however, below the melting point 

 of the base are supersaturated with respect to the solid compound. There exists, 

 however, a difference between liquid hydroxylamine and water, the former not 

 being miscible in all proportions with propyl alcohol. 



That hydroxylamine can occupy the place of the hydrate water in salts has 

 beenproved by Crismer, who has prepared the salts ZnClj, 2NH2OH, BaClj, NHoOH, 

 &c. ; by means of dry ammonia Crismer has prepared the free base irom these 

 double-compounds. 



The presence of the hydroxyl group in hydro-xylamine explains the analogies 

 between this substance and water; the difference in their behaviour must be 

 explained, at least partly, by the greater molecular weight of the former. 



