SCIENTIFIC CONGRESS OF CARLSRUHE. 361 



III. 



New Hydrocarburets — Picric Combinations — Industrial Processes — Different Species of 

 Oxygen — Science and the Metrical System — International Relations and the Metrical Sys- 

 tem — Standard Liquors. 



At the second meeting facts of great importance were communicated 

 by MM. Fritzsche, Kuhlmann, Schoenbein, and Mohr. The first 

 exhibited several new hydrocarburets which he had discovered in the 

 tar proceeding from the distillation of wood ; and adverted to a char- 

 acteristic property of certain hydrocarburets of forming definite com- 

 binations with picric acid. This property, equally a discovery of the 

 Kussian chemist, will be found described in a French publication, the 

 11 Journal de Chimie et de Pharmacie," 1858, vol. XXIV, p. 158. 



The novel facts brought to the notice of the association by M. Kuhl- 

 mann, were the result of inquiries having their origin in the desire to 

 render salubrious a form of industry which has heretofore been the 

 reverse, the fabrication, namely, of artificial soda, after the process of 

 Leblanc. In this pursuit the transformation of marine salt into the 

 sulphate of soda gives rise to streams of chlorhydric gas, a part of 

 which diffuses itself in the atmosphere, which it renders unwholesome 

 to animals and even plants. We need not speak of the attempts made, 

 up to this time, to remedy this state of things, but we can certify that 

 M. Kuhlmann has succeeded so well that he draws benefit and profit 

 from it. Hence he was induced to give his process at length, that it 

 may be available to all. In few words this process is as follows : 



In the current of the acid gases, he places lumps of the carbonate of 

 baryta, which occurs in masses in the mineral kingdom. By the 

 action of the chlorhydric gas, the carbonate is decomposed, and is re- 

 placed by a useful product, the chloride of barium, which, by means 

 of sulphuric acid, may be easily transformed into sulphate of baryta, 

 a substance much in request at present, and of which M. Kuhlmann 

 himself manufactures 2,000 kilogramms a day. 



An improvement is adopted the moment the manufacturer finds his 

 account, in doing so, and such will be the case with this process, whicli 

 will supply the means of disinfectment for many localities. It is not 

 meant that the carbonate of barytas alone is available under such cir- 

 cumstances. At no distant day, when the chloride of calcium shall 

 have undergone proper applications, this carbonate may be advanta- 

 geously substituted for the other. 



Another new fact which M. Kuhlmann had realized, relates to the 

 employment of a residuum of a different kind, but at least as insalu- 

 brious as chlorhydric gas ; the masses, namely, of chloruret of man- 

 ganese, resulting from the manufacture of chlorine, which accumulate 

 by millions of litres around the workshops, without a possibility of 

 being conveniently gotten rid of; for there can be no question here of 

 discharging the accumulations either into the river or the subterranean 

 conduits, whose waters would be thereby rendered unwholesome. We 

 may add that this residuum of the chloruret of manganese retains a 

 sufficiently large proportion of chlorine to make the economizing it an 

 object of importance : since, in France alone, the waste of chlorine in 



