516 
Proceedings of the Royal Society 
3. On the Practical Application of Reciprocal Figures to 
the Calculation of Strains on Framework. By Pro- 
fessor Fleeming Jenkin. 
4. On a New Synthesis of Ammonia. By A. R. Catton, Esq., 
late Fellow, and P. T. Main, Esq., Fellow of St John’s 
College, Cambridge. 
It having been shown by one of us that formic acid is produced 
by the union of carbonic acid and nascent hydrogen, it occurred to 
the authors to try whether other gases might not be made to 
unite directly with nascent hydrogen. Such experiments gave the 
prospect of being of especial interest in the case of nitrogen, as it 
was possible the synthesis of ammonia might thus be effected by 
the direct union of nitrogen and hydrogen. 
With this view pure nitrogen and aqueous vapour were passed 
over sodium. The nitrogen was prepared in the usual manner, by 
passing atmospheric air over heated copper, and was freed from 
ammonia by passing it through sulphuric acid. Not a trace of 
ammonia, however, was obtained in this way. When, however, 
nitrogen and aqueous vapour were passed over heated magnesium 
ribbon, a very appreciable quantity of ammonia was produced, and 
the quantity appeared, within certain limits, to be greater the 
higher the temperature to which the magnesium was heated. The 
ammonia was recognised in the usual way — by the smell, by its 
browning considerable quantities of turmeric paper, and by the for- 
mation of the double chloride of platinum and ammonium. The 
theory of this reaction evidently is, that the magnesium decomposes 
the aqueous vapour, and that the hydrogen thus produced, when in 
the nascent state, combines with some of the nitrogen, and forms 
ammonia. Only a small part of the nitrogen, however, is in this 
way converted into ammonia. One cause of this evidently is that 
the magnesia produced during the reaction forms a coating on the 
surface of the magnesium ribbon, and so protects it from further 
action. For this reason it has occurred to the authors that larger 
quantities of ammonia may be obtained by using powdered mag- 
nesium, either by itself or mixed with fine sand, as in Larkin’s 
