110 Scientific Intelligence. 



s 



wholly or in part used. The light seemed equal to that from an equal 

 number of gas jets, and was remarkably white. G. C. S. 



9. On a new Acid of Sulphur ; by MM. Fordos and Gelis, (ibid.) 

 M. Plessy has recently announced the discovery of several new sul- 

 phur acids, but the uncertainty of the analysis left a doubt upon their 

 existence. These acids were supposed to be formed by the reaction of 

 sulphurous acid in solution upon proto- and perchlorid of sulphur. In 

 the present memoir it is conclusively shown that the product is the same 

 in both cases, and if time for spontaneous decomposition is not allowed, 

 the salts of the new acid (and there is but one) may be obtained in a 

 state of almost perfect purity. 



To a given quantity of solution of sulphurous acid, one-tenth its 

 weight of perchlorid of sulphur is to be added — the solution, evaporated 

 to one half, is to be saturated with carbonate of lead, to remove sul- 

 phuric and hydrochloric acids. The chlorid of lead in solution is 

 thrown down by alcohol. The lead is next precipitated by sulphuric 

 acid and the liquid filtered and saturated by the carbonate of barytes. 

 The filtered barytic solution precipitated by absolute alcohol furnishes 

 the new salt. The salts of this acid are S 5 5 MO. The same for- 

 mula was assigned by Wackenroder to a sulphur acid formed by the ac- 

 tion of sulphureted hydrogen upon solution of sulphurous acid, — al- 

 though no analysis was made, it now appears that the formula is correct 

 and that the same acid is formed under these very different circum- 

 stances. This acid completes the series containing 5 equivalents of 

 oxygen, for which apart from theoretical considerations, Messrs. F. and 

 G. propose retaining the names proposed by Berzelius. We have 

 then — 



Dithionic acid, S 2 5 hydrosulphuric acid of Gay Lussac and Walter. 



Trithionic S 3 5 sulpho-hyposulphuric of Sanglois. 



Tetrathionic S 4 5 first acid of Fordos and Gelis. 



Pentathionic S 5 5 new acid of u u 



The pentathionate of baryta is white, and can hardly be distinguish- 

 ed from the tetrathionate, but by analysis — it is however more soluble 

 and more easily decomposed ; a solution of it is precipitated yellow by 

 nitrate of suboxyd of mercury. Chlorine and hypochlorites transform it 

 at once into sulphate ; permanganate however retains its color and only 

 decomposes in presence of much acid. Iodine is not taken up by it. 

 Heat evolves sulphur and sulphurous acid and sulphate of baryta re- 

 mains. The dilute free acid is very alterable, acid and bitter, and red- 

 dens litmus. 



The baryta salt contains 2 equiv. water, which may be wholly or in 

 part replaced by alcohol. 



The new acid, it is to be remarked, is isomeric with the hyposulphu- 

 rous (S 2 2 ), but its capacity of saturation, &c, is very different. 



In conclusion the authors remark that while studying the chlorids of 

 sulphur, they have ascertained that they correspond in composition with 

 the acids of the thionic series — taking CI for O. G. C. S. 



10. On a new Borate of Soda ; by Dr. P. Bolley, (Liebig's Ann., 

 Oct., 1848, in Chem. Gaz.) — The evolution of ammonia from the mixed 



