448 Notices of the Labours of Continental Chemists. 



then evaporated, the ammonia being carefully replaced from 

 time to time (excess is to be avoided), a compound crystallizes 

 out in dark violet grains which contains ammonia combined 

 with Htematein ; these crystals must be quickly filtered off and 

 dried by pressure and exposed to the air, but heat must not be 

 employed. The mother liquor may be precipitated by means 

 of acetic acid, haematein falls down in the form of an ochre- red 

 voluminous body like hydrated sesquioxide of iron; when dried 

 it is dark green with a metallic glance, red by transmitted 

 light; the powder is red. Slowly soluble in cold, easier in boiling 

 water. Soluble in alcohol with a reddish brown colour, very 

 little soluble in aether; dissolves in potassa with a blue co- 

 lour, which^exposed to the air passes through red into brown ; 

 with ammonia it gives a purple solution which soon turns into 

 brown; formula C 40 H 30 O 16 . Haematoxylin absorbs 3 atoms 

 of oxygen under the influence of ammonia, and forms haema- 

 tein, and 2 atoms of water, C 40 H 34 O 15 + O 3 = C 40 H 30 

 16 +H 4 2 . 



No carbonic acid is formed during the change. 



Haematein-ammonia is a bluish-black or rather violet-black 

 powder, which under the microscope is seen to consist of 

 quadrilateral prisms. It is soluble in water with an intense 

 purple colour, with alcohol it gives a reddish-brown solution. 

 Heated to 100° C. it loses water and ammonia, it must there- 

 fore be dried over sulphuric acid. When dry it does not 

 decompose of itself, but if moist or in solution a spontaneous 

 decomposition takes place. ' Formula C 40 H 44 N 4 O i7 ; con- 

 sequently 1 atom of haematein takes up 2 atoms of ammonia 

 and 1 atom of water. Erdmann gives the ammonia com- 

 pound the formula C 40 H 28 O 15 + 2 N 2 H 8 O, and haematein 

 C 40 H 28 O 15 + H 2 O. 



Haematein-ammonia gives coloured precipitates with most 

 metallic solutions. The lead compound is blue, but it is basic, 

 for the supernatant solution is acid ; at first the washings are 

 colourless, but soon become brown-coloured : it is probable 

 that under the influence of oxide of lead, air and moisture, 

 the haematein undergoes slow oxidation and decomposition. 

 The blue compound was washed a little and then analysed : 

 the organic part of it agreed pretty well with the formula 

 C 40 H 28 O 15 . 



A reddened solution of haematoxylin is decolorated by 

 sulphuretted hydrogen, and on evaporation pure haematoxylin 

 is obtained ; a solution of haematein is also rendered colour- 

 less by sulphuretted hydrogen, but in this no reduction 

 takes place, for on evaporating, as the gas is driven off the 

 solution acquires its original dark colour, and crystals of hae- 



