SODIUM.
847
case. The calcium sulphate found in Sciiaffner’ssulphur only proceeds from the sulphuric acid alwayspresent in common muriatic acid.
There is nothing peculiar in Mond’s way of filter-ing, washing, and drying the sulphur. He used tomelt it by an apparatus different from Sciiaffner’s,probably only for the reason that the latter wasprotected by patent; but it does not appear thatany of the many modifications proposed is equalto Schaffner’s melting process.
Mond’s process has been carried out for manyyears past by several English alkali works, and mustbe pronounced successful, especially if combinedwith Schaffner’s melting apparatus, and if carriedout in separate tanks, so that four or five repetitionsof the oxidation can be practised.
By none of the methods hitherto proposed isthe tank waste really “ desulphurised.” In thebest case, about half of the sulphur combined isrecovered as such, mostly less than that; one factoryin Lancashire obtains 6 per cent., another, nearBristol, 8 per cent, of sulphur upon the sulphate ofsoda originally balled. The remainder, to some likeextent, is lost in a gaseous form during the recoveryprocess; mostly, however, it exists in the oxidisedand lixiviated waste as calcium sulphite and sulphate,even of free sulphur, and always to a certain extentof calcium sulphide, even after many successiveoxidations. This “desulphurised” waste is of coursevery much less liable to give rise to a nuisance thanordinary tank waste ; but it would seem desirable todispose of it otherwise than by depositing it on wasteground, and perhaps Mond’s proposal to burn it incement kilns, and use it similarly to Scott’s seleniticmortar may lead to its better utilization. Mactearlias patented a plan for dealing with the yellowliquors from old tank heaps. Its only new featureis the treatment of such liquors by sulphurous acid,in order to “ correct ” them, and to make theircomposition similar to that indicated above; afterthis the ordinary process of Mond is carried out.
Cost of Production. — The following calculationshows the actual cost of production (from themanufacturing books) of soda ash (yellow carbonate),at a Tyneside manufactory in the beginning of 187(5.
Tons. £ s. D. £ s. i>.
48 per cent, (copper not >- 0*8626 at 0 16 0 0 13 9
paid for).)
Nitrate of soda (deducting)
from the price the value > 0'0155 at 10 10 0 0 3 3
of the nitre cake),.)
Common salt,. 1*3175 at 0 18 0 13 9
Chalk,. 1*732 at 0 4 0 0 6 11
Coals for mixing,. 0*750 at 0 6 0 0 4 6
“ for firing,. 2*410 at 0 5 0 0 12 1
Wages,. 1 14 9
Repairs and stores,. 0 11 1
Removal of tank waste,. 0 2 6
Casks and delivery on board ship. 0 12 0
Management, foremen, general expenses of all kinds, 0 9 4
6 13 11
This is the cost of a ton of ash, f.o.b. in the Tyne,such as it is furnaced, whether 51 or 53 per cent.,as made by the old hand-furnace ; revolver ash ischeaper and stronger. It is scarcely necessary to
say that several or even most of the items differaccording to the variations in the price of rawmaterials (pyrites, for instance, was fully 25 per cent,cheaper in 1870 than in 1875), in the size of thefactory, its local advantages or drawbacks, and theskill and care displayed in its management.
James Young, F.R.S., revived in 1871 theammonia process for making carbonate of soda,which had been patented, if not originally invented,by Dyer and Hemming. The reaction worked outby these chemists nevertheless failed to produce intheir hands a good commercial process, on accountof the loss of ammonia in the manufacture. Young’simprovements consist in a method of working bywhich the ammonia, when once put into the appara-tus, is never again exposed to the atmosphere.The vessels communicate with each other, so thatwhen carbonate of ammonia is mixed with thecommon salt, treated with carbonic acid, and decom-posed, forming bicarbonate of soda and chloride ofammonium, this latter salt is passed through aclose tube into another vessel, where it is decom-posed by lime, and the ammonia passed along withcarbonic acid into a second solution of commonsalt, and so on continuously, making a circuit of thevessels. Part of this carbonic acid is obtainedfrom the solution of bicarbonate of soda, which isboiled in the vessel in which it is formed, until itgives off part of its carbonic acid and any ammoniawhich may remain attached to it.
This process was carefully worked at by Youngfor a long time, and its practicability fully demon-strated, before he made it known; but he neverbrought the soda into commerce, not wishing againto enter into business, but preferring to leave thematter to others. There is a probability tliat^it willcome more extensively into use, as the work iseasy, and it is free from the so-called noxiousvapour—muriatic acid. The value will greatly de-pend on the price of ammonia; but it will alsodepend on the convenience of the position, as theammonia process may be carried on where the acidprocess could not be permitted. At any rate, thisis an important new process of manufacture, and itstrue value will not be easily seen for a long time.Should circumstances at any time render ammoniaeven but a little cheaper, it would probably becomea very general process.
SODIUM.— Sodium, English and French ; Natrium ,German and Latin . Symbol, Na; atomic weight23.—This metal was isolated in 1807 by Sir Hum-phrey Davy , through the agency of voltaic elec-tricity. Moistened sodium hydrate was employed,the oxygen both of the water and of the soda wasliberated at the positive pole, and the sodium andhydrogen at the negative pole.
Sodium is a monatomic metal. With chlorine,fluorine, bromine, and iodine, it forms the com-pounds NaCl, NaFl, NaBr , Nal; with oxygen itforms a monoxide (Na 2 0) and a dioxide (Na 2 0 2 );with sulphur a monosulphide (Na 2 S), and its hydrate(STaHS), and many polysulphides.
The processes already described for the produc-