.Chemical Science. 195 



yellow tinted liquid is slightly acid ; it is to be quickly evaporated in 

 a tin vessel by a water-bath, until like honey, when it will appear as 

 a yellow, bitterish mass, having an odour like that of osmazome. 

 Six or eight times its weight of strong alcohol is immediately to be 

 added, and a tincture will be obtained yellow, slightly acid, and pro- 

 ducing a strong red colour with persalts of iron. This tincture 

 being distilled, the product has no power of affecting persalts of 

 iron. The red-brown, syrupy, transparent matter left in the retort, 

 crystallizes by slow cooling, or becomes a granulated mass if 

 agitated: being allowed to drain on a cloth, then pressed, then puri- 

 fied two or three times in very strong alcohol, its bulk increases 

 much, and it ultimately appears as a white crystalline substance, and 

 is sulpho-sinapisine. Further portions may be obtained by evaporat- 

 ing the mother liquor : the crystalline masses obtained require to 

 be digested in ether to separate a volatile red body soluble in 

 that fluid. 



Sulpho-sinapisine is white, inodorous, bitter, very light, soluble in 

 water and alcohol, and more so when hot than when cold. When 

 hot saturated solutions are cooled, acicular crystals in rounded 

 groupes are produced ; they]are most distinctly formed in acidulated 

 water. When heated, it fuses, and is decomposed, yielding fetid 

 products, amongst which are carbonate and hydro-sulphuret of 

 ammonia. The substance is not naturally acid, but yields an acid 

 by various modes of treatment. 



Being analysed, its ultimate composition appeared to be per cent. 



Carbon 50.504 or by theory 50.504 



Hydrogen . . 7.795 7.795 



Nitrogen... 4.940 5.020 



Sulphur 9.657 9.657 



Oxygen.... 27.104 27.024 



As the nitrogen and sulphur are nearly in the proportions 

 belonging to sulpho-cyanogen, we may consider sulpho-sinapisine 

 as represented by sulpho-cyanogen, and an organic matter not 

 azoted, which may perhaps be competent to form the volatile oil of 

 mustard. 



Sulpho-Sinapisine, with nitric acid, is instantly altered ; a bright 

 red colour is produced, much orange-coloured gas formed, and sul- 

 phuric acid appears. With muriatic acid it is dissolved, and be- 

 comes green ; heat then produces a strong odour of prussic acid. 

 Distilled with sulphuric or phosphoric acid, sulpho-cyanic acid is 

 obtained, and, with the first, sulphuretted hydrogen also. With 

 chlorine, prussic acid and sulphuric acid were formed. 



When treated with alkalies the following were the principal 

 results. Ammonia dissolved it, but effected little change. Potassa 

 and soda, with a little water, changed the colour to red and green ; 

 being evaporated and dried, much volatile oil of mustard rose. 

 Then the substance fused > and was found to be sulpho-cyanide 

 of potassium; further heat destroyed this state of things, leaving 



