TRANSACTIONS OF THE SECTIONS. 63 



coarse powder, and the oxygen expelled. It was first exposed in a mnltie to a 

 red heat for some hours in a current of air, so as to secure its perfect oxidation, 

 and removal of every trace of organic matter. The powdered ore was then placed 

 in a red-hot porcelain tube, and a stream of hydrogen gas passed over it imtil all 

 the oxygen of the peroxide of iron was removed. The completeness of the de- 

 oxidation was judged of by weighing the water produced by the operation. 



A quantity of carbonic oxide, in this instance prepared from ferrocyanide of 

 potassium, was examined, and its freedom from water, carbonic acid, oxygen, 

 and other impurity carefully seciu'ed by passing it successively through a series of 

 tubes containing pyrogallate of soda, potash, and sulphuric acid. 



Two himdred' grains ( = 12-9598 grammes) of the deoxidized ore were placed in 

 a glass combustion tube, and heated by a Hofmann's gas-lamp, so that the neces- 

 sary temperature was under easy control. 



Ten litres of the carbonic oxide were passed over the ore, which was never per- 

 mitted to be red-hot, and to secure the temperatm-e being high enough, a piece of 

 zinc placed on the tube was maintained in a melted state. Four hours and a quar- 

 ter were required for the operation. 



The gas, as it passed away, was exposed to the action of a solution of potash, 

 which of course absorbed any carbonic acid generated, and which was found to 

 amoimt to 9-9 grains (=0'641 gi-amme). 



The ore on cooling, without exposure to the atmosphere, was ascertained to 

 have increased 3 grains (=0-1942 gramme). The 203 grains ( = 13-155 grammes) 

 thus obtained were mixed -with chromate of lead, placed in a tube, and heat 

 applied. 



The resulting carbonic acid was collected in the usual way. It weighed 10-G6 

 grains (=0-G903 grm.) equal to 2-907 gi-ains ( = 0-1882 gmi.) of carbon. 



This experiment then gives 9-9 grains (=0-641 gramme) of carbonic acid, pro- 

 duced directly by the action, and 10-66 grains (=0-6903 gramme) obtained by 

 the deposited carbon, the difference being probably due to error of manipulation. 



In another form of experiment 1000 cubic centimetres of carbonic oxide were 

 passed and repassed from one graduated vessel over the heated ore into another 

 similar vessel (both over mercmy ), so that the change of composition, as denoted 

 by the change in volume, could be ascertained. It was found in this experiment 

 and in others that, as the temperatm-e was raised above that of redness, the action 

 gi-adually diminished. At a heat approaching whiteness the carbonic acid obtained 

 from the ore which had been exposed for some hoiu's to the action of carbonic oxide 

 was so minute (-25 per cent of the weight of the ore) as to render it probable that 

 it was due to the occlusion of a portion of the oxide of carbon, a view which was 

 confirmed by the fact that no flakes of carbon were perceptible on dissolving the 

 ore in hydrochloric acid. 



When the treatment is continued long enough, the deposition of carbon in the 

 interstices of some pieces of the ore is so copious that they are burst open as lime is 

 with water on being slaked. Upon one occasion the ore was found, after nine 

 hours' exposure, to contain 24 per cent, of its weight of carbon. 



On Extraction of Ammonia from Gas-Liquor. By Feebeeick Beaby, F.C.S. 



Gas-liquor was formerly a drug in the market and a ntusance to the manufac- 

 tm-er ; it was given away to any one that would use it, now it is the principal 

 source of ammonia and of its salts. The object of this paper is to show how the 

 demand for gas-liquor, which far exceeds the supply, can be met, and to prove how 

 (by reduction of bulk for transit) small and remote gas-works may export their 

 residual products at a profit ; it is also to show how the production of ammonia 

 may be very greatly increased. 



In its crude state, gas-liquor usually contains one part of ammonia, by weight, 

 to eighty parts of liquor. For all purposes of transit, a very serviceable solution 

 would contain one part, by weight, of ammonia to four parts of water ; this veiy 

 considerable reduction of bulk is effected by means of a rapid and economical 

 process, described in the specification of a patent recently secured by the author, 

 in conj miction with Mr. Baggs. 



