AMMONIA, CARBONATE OF 145 



He also proposes to prepare carbonate of ammonia from the sulphide of ammonium 

 of gas liquors, by passing carbonic acid gas into the liquor, which carbonic gas is 

 generated by heating a mixture of oxide of copper and charcoal, in the proportion of 

 twelve parts of the former to one of the latter. 



Mr. Hills has described his mode of obtaining sesquicarbonate of ammonia from 

 guano. To effect this, the guano is first mixed with charcoal or powdi-rod coke ; the 

 mixture is then heated, and the sesquicarbonate of ammonia obtained by sublimation. 

 The process does not appear to be much employed. 



Manufacture of Ammonia from Peat and Shale. Mr. Hills, in his patent of August 

 llth, 1846, specified the following method of obtaining ammonia from peat. The 

 peat is placed in an upright furnace and ignited ; the air passes through the bars as 

 usual, and the ammonia is collected by passing the products of combustion through a 

 suitable arrangement of apparatus to effect its condensation. This plan of obtaining 

 ammonia from peat appears to be precisely similar to that patented by Mr. EeesReece 

 (January 23rd, 1849), and made to form an important feature in the operations of the 

 British and Irish Peat Company. The first part of Mr. Reece's patent is for an in- 

 vention for causing peat to be burned in a furnace by the aid of a blast, so as to obtain 

 inflammable gases and tarry and other products from peat. For this purpose, a blast 

 furnace with suitable condensing apparatus is used. The gases, on their exit from the 

 condensing apparatus, may be collected for use as fuel or otherwise ; and the tarry and 

 other products pass into a suitable receiver. The tarry products may be employed to 

 obtain paraffine and oils for lubricating machinery, &c. ; and the other products may 

 be made available for evolving ammonia, wood-spirit, and other matters by any of the 

 existing processes. Dr. Hodges, of Belfast, states that in his experiments he obtained 

 nearly 22|lbs. of sulphate of ammonia from a ton of peat. Sir Robert Kane, who 

 was employed by Government to institute a series of experimental researches on the 

 products obtainable from peat, states that he obtained sulphate of ammonia at the rate 

 of 24^1bs. per ton of peat. Messrs. Drew and Stocken patented, in 1846, the obtain- 

 ing ammonia from peat by distillation in close vessels, as practised in the carbonisation 

 of wood. It will thus be seen that the peat is a source of ammonia, but whether this 

 source is a profitable or economical one, in a commercial point of view, is a problem 

 which has not yet received solution. 



Ammonia from Schist. Another source of ammonia is bituminous schist, which, 

 when submitted to destructive distillation, gives off an ammoniacal liquor which may 

 be employed in the manufacture of ammoniacal salts by any of the usual processes. 

 The obtaining of ammonia from schist forms part of a patent granted to Count do 

 Hompesch, September 4, 1841. 



Chemical Composition and Constitution. The true neutral carbonate of ammonia, 

 NH 4 0, CO* [(XH 4 ) 2 CO*J, does not appear to exist. The sesquicarbonate of ammonia 

 of the shops was found by Rose to have the composition assigned to it by Mr. 

 Philips, as given at the head of this article ; and it may be viewed as a compound of 

 the true bicarbonate (i.e. the double carbonate of ammonia and water), NH 4 0, CO' ; 

 HO, CO 2 [(M'H 4 ) 2 CO S ; H 2 CO S ] ; with a peculiar compound of anhydrous carbonic 

 acid with ammonia itself, NH 3 , CO 2 [(WH S ) 2 CO 2 ]. 



It is invariably found that a certain quantity of water and ammonia are liberated 

 during the distillation, and hence the anomalous character of the compound. In fact, 

 in operating upon 3 equivalents of the sulphate or chloride of the 3 equivalents of the 

 true carbonate of ammonia (NH 4 0, CO 2 ) which may be supposed to be generated, 

 two are decomposed, one losing an equivalent of ammonia, the other an equivalent of 

 water ; of course, the ammonia thus liberated, amounting to 14 parts for each 100 of 

 carbonate of ammonia obtained, is not lost ; it is passed into water to bo saturated 

 with acid, and thus again converted into sulphate or chloride. 



Properties. Sesquicarbonate of ammonia (as it is commonly called) is met with 

 in commerce in the form of fibrous white translucent cakes, about two inches thick. 



When exposed to the air the constituents of the less stable compound NH S , CO 2 are 

 volatilised, and a white opaque mass of the true bicarbonate remains. Hence the 

 odour of ammonia always emitted by the commercial carbonate. Mr. Scanlan has 

 also shown that by treatment with a small quantity of water, the carbonate is dissolved, 

 leaving the bicarbonate. It is soluble in four times its weight of cold water, but 

 boiling water decomposes it. 



Impurities. The commercial salt is sometimes contaminated with empyroumatic 

 oil, which is recognised by its yielding a brownish coloured solution on treatment 

 with water. 



It may contain sulphate and chloride of ammonium. For the recognition of the 

 presence of these acids, see SULPHURIC and HYDROCHLORIC acids. 



Sulphide and hyposulphite of ammonia are sometimes present, and likewise lead, 

 from the chambers into which the salt has been sublimed. 



VOL. I. L 



