34 report — 1842. 



The colour of hematoxylin varies from a pale reddish yellow to a pale honey 

 colour. The crystals are transparent, possess a strong lustre, and may be obtained 

 a few lines in length. Their form is a rectangular, four-sided prism, sometimes with 

 a pyramidal summit. The taste of hematoxylin is similar to that of liquorice ; it is 

 not' very soluble in cold water, but dissolves freely, with a yellow colour, in boiling 

 water. Its solutions are reddened by the action of ammonia and oxygen. Oxygen 

 alone is incapable of producing this effect, but the most minute trace of ammonia 

 imparts a purple colour to the solution. Hematoxylin forms, theiefore, the most 

 delicate test for ammonia, and is the easiest method of proving its presence in the 

 atmosphere. Hematoxylin is soluble in alcohol and ether. When exposed to the 

 influence of light it acquires a reddish tinge ; on being heated it is decomposed, 

 without giving any sublimate. It contains no nitrogen. When heated in the water- 

 bath it loses 16 "per cent, of water. The dry substance possesses the formula 

 C H 17 1S . There are two hydrates of hematoxylin. Acids do not act so ener- 

 getically on hematoxylin as bases. All the compounds of hematoxylin and bases 

 are decomposed by air and moisture. 



The formation of the blue or red colouring matters which hematoxylin is capable 

 of producing, takes place in general by the mutual influence of bases and oxygen. If 

 an excess of ammonia or potash be added to a solution of hematoxylin, the liquid 

 becomes at first of a deep red colour, afterwards opake and of a dark red. After 

 the lapse of some time it loses its red colour altogether, becoming of a dirty brown 

 hue. When acetic acid is added to the solution, a voluminous brown precipitate is 

 obtained ; this body the author calls htematein. When the red solution is cautiously 

 evaporated, a substance of a dark violet colour is deposited ; this body is hamatem- 

 ammonia. Hematein is analogous to orcein, phloridzein, &c. ; it dissolves in water 

 with a purple colour ; by evaporating the solution, the whole of the ammonia is ex- 

 pelled, and pure hematein remains. Hematein differs from orcein in containing no 

 nitrogen : its formula is C 4n H ls 1B . Hematoxylin, therefore, in passing into 

 hematein, under the influence of ammonia, takes up three atoms of oxygen, two of 

 which combine with two of hydrogen to form water, and the third remains in the 

 compound C, n H, 7 15 + 3 = C, H J5 0, 6 + H 2 2 . Hematein-ammonia is com- 

 posed as follows :— C H 2 o N, 17 , which is equal to C 40 H u 1S + 2 N H 4 O. 

 Hematein must therefore have the following composition :— C 4Q H u 15 + H O. 

 Hematein may be combined with most metallic oxides. Hematein is decolorized 

 bv sulphuretted hydrogen, but this is not the effect of reduction, for the solution re- 

 gains its red colour when evaporated in vacuo. The author concurs. with Chevreul's 

 view, in supposing that sulphuretted hydrogen acts on reddened hematoxylin or 

 hematein in the same manner as a weak acid. 



On the Formation of Cyanuret of Potassium in a Blast Furnace. 

 By Dr. C. Bromeis of Cassel. 

 M. Zincken discovered, at the bottom of the blast furnace at Magdesprung in the 

 Hartz Mountains, a mass which Dr. Bromeis found to contain ferrocyanuret of po- 

 tassium. The furnace from which it was obtained had been fed with charcoal. The 

 other ingredients of the saline mass were caustic potash, carbonate, silicate, and 

 manganate of potash, together with a large proportion of cyanate of potash and 

 cyanuret of potassium. It is probable that the ferrocyanuret of potassium did not 

 exist ready formed in the mass, but was produced after dissolving the cyanuret of 

 potassium in water. The cyanate of rfotash, by its decomposition, gives rise to car- 

 bonate of potash and ammonia. Dr. Bromeis supposes that the formation of cya- 

 nogen must have been occasioned in the following mariner : — The nitrogen of 'the 

 atmosphere being exposed to a great pressure and high temperature, combined directly 

 with the carbon of the carburet of potassium, producing thereby cyanogen and cya- 

 nuret of potassium. This explanation accords with the experiments of Defossc. 



On the Compounds of Carbon and Iron. By Dr. C. Bromeis. 

 Dr. Bromeis analysed various kinds of iron by burning them in a tube, with a 

 mixture of chromate of lead and chlorate of potash. The combustion is conducted 



