CHEMICAL SCIENCE. 273 



discovery of a new method for procuring protoxide of nitrogen with 

 the aid of a very low temperature. Among the experiments, the 

 following were quantitative. T\vo grammes of sal-ammoniac were 

 placed in a glass flask, and half an ounce of nitric acid poured upon 

 it, the flask was connected with a small wash bottle containing a little 

 water, and from this latter a tube passed into a pneumatic trough filled 

 with hot water, he;it was applied to the flask, and before the tempera- 

 ture reached 140 Fah., a gas began to be given off, and at 160 

 it came off rapidly and continued to do so after the lamp was 

 withdrawn. A small amount of red fumes appeared in the flask, 

 that were condensed in the wash bottle, the gas that passed over 

 was collected in a receiver, and measured 1008 cubic centimeters; 

 the gas smelt of chlorine, the flame of a candle burnt with an increased 

 brilliancy when introduced in it, the candle was re-ignited when 

 extinguished, if a burning coal remained on the end of the wick 

 no red fumes were formed when it came in contact with the air, and 

 the gas was absorbable by cold water. The properties were those of 

 protoxide of nitrogen. In another experiment the gases were collected 

 at different stages of the process, in vials over hot distilled water, and 

 a solution of caustic potash introduced and shaken up for some time ; 

 this latter was subsequently analyzed for the chlorine it absorbed, and 

 in three different portions, collected at the beginning, middle, and 

 end of the process, the proportions of the chlorine to the whole bulk 

 of the gas were 1-57, 1-29, and 1-16. The amount of protoxide of 

 nitrogen due to the ammonia in two grammes of sal-ammoniac and 

 its equivalent of nitric acid, is 887 cubic centimeters. The gas freed 

 from chlorine, on being shaken up with cold water for some time, was 

 found to be almost entirely absorbed by the water. What remained 

 was a mixture of nitrogen and a little air; some nitrous or hyponitrous 

 acid forms during the whole process, if concentrated nitric be used; 

 if, however, it be diluted, little or none is formed, and the gas is readily 

 given off at about 212. 



In all my experiments, the protoxide of nitrogen constituted from 

 seven-eighths to twenty-four-twenty-fifths of the gaseous products, and 

 when washed from its chlorine by a little lime-water or soda, possessed 

 all the properties of pure protoxide of nitrogen, and I would recom- 

 mend it as a convenient way of forming this gas, especially when not 

 required for respiration. 



The character of the decomposition which takes place, is somewhat 

 curious and unexpected. At first, I supposed that the decomposition 

 resulted in the formation of equal volumes of N, O, Cl, and N, but it 

 appears that such is not the case, and that all but a very small portion 

 of the ammonia, with its equivalent of nitric acid is converted into 

 N, O ; the liberated hydrochloric acid mixing with the excess of nitric 

 acid does undergo the decomposition first supposed, and in this way 

 only can the small amounts of chlorine and nitrogen be accounted for. 

 At the time this method was first tried, I also tried the decomposing 

 effects of nitrate of ammonia on sal-ammoniac, that has been shown 

 by Maumone to result in the formation of chlorine and nitrogen ; but 



