CHEMISTRY. 



115 



The Societe de St. Croix at Lisle is manu- 

 facturing potash upon a large scale by the 

 trimethylamine process, which is similar in 

 principle to the ammonia process for the man- 

 ufacture of soda. The latter process can not 

 be used for the manufacture of potash, by rea- 

 Bon of the too great solubility of hydro-potassic 

 carbonate in solution of ammonium chloride. 

 Bicarbonate of potash is, however, but very 

 slightly soluble in chloride of trimethylamine. 

 Besides the nature of the ammonia employed, 

 the chemistry of this process appears to differ 

 from that of the ammonia process also in the 

 fact that, instead of using a bicarbonate as in 

 that process, the sesquicarbonate, the highest 

 carbonate of trimethylamine that can be ob- 

 tained at present in a free state, is employed, 

 and the reactions are more complex. The tri- 

 methylamine process is limited in its applica- 

 tion, for it is available for the manufacture of 

 potash only from potassium chloride, while the 

 Engel process is efficient either with that salt 

 or with the sulphate. 



G. Archibald describes a new industrial 

 method of preparing paper-pulp, which has 

 been patented in the United States and Canada. 

 Wood or straw is cut to pieces, macerated with 

 milk of lime, transferred to a digester after 

 twenty-four hours, and saturated with sulphur- 

 ous acid, with the simultaneous application of 

 a pressure of five atmospheres for one or two 

 hours. The material is then washed with water 

 and again treated under pressure with three 

 per cent, calcium chloride and half per cent, 

 aluminum sulphate. After these substances 

 have been washed out, the pulp resembles cot- 

 ton in appearance, and can be employed for 

 manufacturing the finer grades of paper at once. 

 The process requires about three hours after the 

 treatment with milk of lime. 



A.Houzeau and Fr.Goppelsroeder have traced 

 the active agency in grass- bleaching, which 

 Schoenbein ascribed to ozone, to peroxide of 

 hydrogen. The proportion of this substance in 

 the air was found to differ, according to a va- 

 riety of circumstances ; and the preponderating 

 influence in its production is believed to be 

 light. Atmospheric precipitations, particularly 

 hoar-frost, contain considerable quantities of it ; 

 and the quantity that came to the earth within 

 four months was found to amount to 62-9 mil- 

 ligrammes per square metre. The ordinary pro- 

 cesses of open-air 'and wax-bleaching are at- 

 tended with so many inconveniences in delays 

 that the production of the effective agent in a 

 concentrated form was suggested as a manifest 

 remedy. The peroxide of hydrogen is superior 

 to all other media for oxidation in bleaching, 

 in that it can be used without inconvenience 

 and without any danger of injuring the fiber. 

 It may be concentrated from its solutions by 

 freezing out, or by evaporation in a vacuum 

 over sulphuric acid, at a temperature of from 

 69 to 68 Fahr. Diluted solutions of it are 

 equal to solution of chlorine in effect, and will 

 keep for months in a temperature not exceed- 



ing 77 Fahr., if protected from the light. All 

 products which are to be bleached by this 

 substance must be submitted to a preparatory 

 treatment, the purpose of which is to render 

 them capable in every part of being moistened 

 with the watery solution. 



Dr. Max Schaffner and Mr. W. Helbig, of the 

 Aussig Works, Bohemia, have applied a pro- 

 cess for recovering sulphur from alkali-waste, 

 which, while it requires no acid, saves the 

 whole of the sulphur originally contained in 

 the waste, and in addition all of the calcium as 

 carbonate. It includes three operations, the 

 first of which consists in heating fresh waste 

 with solution of magnesium chloride in a closed 

 iron vessel furnished with a mechanical agi- 

 tator, when two double decompositions take 

 place calcium sulphide and magnesium chlor- 

 ide into calcium chloride and magnesium sulph- 

 ide ; and a reaction of the last upon some of the 

 water present to produce magnesia and sulphu- 

 reted hydrogen. The sulphureted hydrogen is 

 evolved in a continuous stream until the charge 

 of waste is completely decomposed, and then 

 there remains in the boiler a solution of cal- 

 cium chloride holding in suspension an equiva- 

 lent of magnesia. In the second operation, 

 one third of the sulphureted hydrogen is 

 burned into SO 2 and steam, and these products 

 are mixed with the other two thirds and passed 

 through a solution of calcium chloride, whence 

 is derived a thin magma, consisting of solu- 

 tion of calcium chloride holding in suspension 

 free sulphur. The third operation consists in 

 injecting carbonic dioxide into the solution of 

 calcium chloride, holding magnesia in suspen- 

 sion, which had been obtained as the residual 

 product of the first operation, thereby repro- 

 ducing the quantity of magnesium chloride 

 which had been begun with, and at the same 

 time regenerating all the calcium carbonate 

 which had been employed for the production 

 of the black ash, of which the waste had been 

 one of the constituents. Mr. Alexander Chance, 

 of Birmingham, has applied a modification of 

 the third part of the process, by which all of 

 the sulphnreted hydrogen evolved in the first 

 operation is burned, and the resulting sulphur- 

 ous oxide is sent into the vitriol chambers, by 

 which the cost of the process is reduced simply 

 to the cost of the operation of reducing the 

 magnesium chloride. 



MM. Benker and Lasne have introduced a 

 process for economizing nitrous compounds in 

 the manufacture of sulphuric acid, which con- 

 sists in the reduction of the nitric peroxide in 

 the chamber gases before they reach the Gay- 

 Lnssac tower into nitrous anhydride (N 2 O S ), 

 which forms a stable compound with sulphuric 

 acid. This is done by injectytg into the con- 

 duit conveying the exit gases from the last 

 chamber to the foot of the Gay-Lussac tower, 

 a regulated quantity of sulphurous oxide, ac- 

 companied with just the quantity of vapor of 

 water necessary to form, with the SOa + NOa, 

 nitro- sulphuric acid. Another plan for accom- 



