404 Chronicles of Science. [ July, 
“On the Estimation of Phosphorus in Iron and Steel.” The 
process usually adopted by analysts is that of Fresenius, which the 
author finds may be considerably curtailed without impairing the 
accuracy of the results. Following Fresenius as far as the partial 
reduction of the ferric solution by sulphurous acid, Mr. Spiller dis- 
penses with the next step—precipitating the phosphoric acid with 
the remaining ferric oxide by boiling with acetate of ammonia—and 
adds sesquicarbonate of ammonia to the partially reduced solution 
until the precipitate, at first red, becomes greenish, showing the 
precipitation of some ferrous oxide. The temperature of the solution 
must not exceed 70° or 75° Fah. while this part of the operation is 
conducted. The precipitate being collected, is next dissolved in 
hydrochloric acid, and to the warm solution is added in succession 
citric acid, ammonia in excess, and sulphide of ammonium. By this 
means the whole of the iron is precipitated, and may be separated 
by filtration. The filtrate being slowly evaporated with full 
exposure to air, and the sulphur deposited removed, the phosphoric 
acid may be precipitated in the usual way. 
Professor Wanklyn afterwards read a paper “On Magnesium,” 
showing the ordinary magnesium ribbon of commerce to be re- 
markably pure, and pointing out the resistance offered by this 
metal to the action of chlorine, bromine, and iodine. The author 
also showed that magnesium-amalgam decomposes water with 
greater facility than sodium amalgam. 
Mr. E. T. Chapman then made some observations “On 
Mercury-Ethyl,’ and Mr. W. A. Tilden read a paper, entitled 
“Further Contributions to the History of the Periodides of Organie 
Bases.” 
Mr. M‘Leod afterwards exhibited an experiment, showing, on a 
large scale, the formation of acetylene by the incomplete combustion 
of marsh gas.* Mr. M‘Leod employed the form of apparatus used 
by Dr. Hofmann to show the combustion of oxygen in hydrogen, 
ammonia, or coal gas, in the present experiment burning the 
oxygen (atmospheric air may be employed) in an atmosphere of 
marsh gas,t and causing the products of combustion to pass into an 
ammoniacal solution of cuprous chloride. Mr. M‘Leod then showed 
the explosive properties of the characteristic red precipitate pro- 
duced by acetylene in the copper solution, and hitherto called 
acetylide of copper, but the exact composition of which has not yet 
been made known. ‘The author believes it to contain cuprous oxide 
in combination with the acetylide. 
Dr. Hofmann subsequently made some observations “On the 
Synthesis of Guanidine.” 
* ¢ Journal of Science’ for April, p. 266. 
+ The apparatus will be found described in the ‘Journal of the Chemical 
Society’ for May, 1866. 
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