518 Chemical Society. 



INIr. G. Lowe observed that the preparation of prussiate of potash 

 from the waste gas liquors was difficult, owing to the presence of 

 sulphur ; but he believed that the suggestions of Professor Liebig 

 would enable chemists to remove this obstacle to the manufacture. 



2. " On the Formation of Mellon," by Mr. E. A. Parnell, of Uni- 

 versity College. 



This paper referred to the decomposition which occurs in the 

 process for mellon, from the substance considered by Liebig to 

 be the isolated radical of the sulphocyanides (as obtained by the 

 action of chlorine or nitric acid on sulphdcyanide of potassium) ; 

 for which substance, having previously shown it to contain hy- 

 drogen and oxygen in addition to the elements belonging to the 

 true sulphocyanogen, the author proposes the term metasulphocyan- 

 ogen. It became necessary, therefore, to seek for other products of 

 the decomposition of this substance than those hitherto recognized, 

 namely, mellon, sulphur, and bisulphuret of carbon ; and in decom- 

 posing pure and dry metasulphocyanogen by heat, water, sulphu- 

 retted hydrogen, and hydrosulphocyanic acid, in addition to the 

 above, were detected. Admitting the formula for metasulphocyan- 

 ogen, S,,! Cyg H3 O, to which he has been led by analyses, the de- 

 composition is explained as follows : — Three equivalents of meta- 

 sulphocyanogen, containing 835 €3,, N,g Hp 0.„ are resolved into 

 four of mellon, C44 Njg ; two of hydrosulphocyanic acid, S4 C4 R, Ho ; 

 four of sulphuretted hydrogen, S4 H4 ; eight of bisulphuret of car- 

 bon, S16 Cs ; twelve of sulphur, and three of water, H3 O3. The sum 

 of the elements of these compounds will be found to comprise 

 S36 Cjs N|g Hp O3 ; or three equivalents of metasulphocyanogen. 



April 27. — The following communications were read : — 



1. A letter from Mr. M. Scanlan, of Wolverhampton, describing 

 the appearance of flashes of light observed during the crystallization 

 of nitrate of strontian in the dark. 



2. " Action of Nitric Acid on Castor Oil," by Mr. T. G. Tilley. 

 (See present Number, page 417.) 



3. "On Bleaching Salts," by M. Detmer, Esq. (See present 

 Number, page 422.) 



4. The following Note by Professor Graham, " On the Preparation 

 of Chlorate of Potash." It is well known that the ordinary pro- 

 cesses for this important salt are attended with some practical diffi- 

 culties. When a stream of chlorine gas is passed through a strong 

 solution of carbonate of potash, the absorption of the gas is rapid 

 and complete, till one-half of the alkaline carbonate is decomposed ; 

 but the remaining portion, which is in the state of bicarbonate, is 

 not so easily acted upon. To decompose the latter salt completely, 

 chlorine must be applied in excess, and the decomposition is attended 

 by the formation of free hypochlorous acid, as has been proved by 

 Mr. Detmer. The liquid is also at the end highly bleaching, and 

 contains much hypochlorite of potash. The boiling necessary to 

 convert the latter into chlorate of potash and chloride of potassium 

 occasions, according to M. Morin, a considerable loss of oxygen, 

 and thus lessens the product of chlorate. When a strong solution 



