154 Miscellaneous Intelligence. 



nitrate or sulphate of copper added, makes them appear blue-; 

 Acid again makes them appear red. 



With regard to the phenomena attending the production of 

 cerulin, when indigo is put into sulphuric acid, it is dissolved, 

 and a yellow fluid results, rendered blue by water. The blue 

 precipitated is indigo unchanged ; but if the yellow solution be 

 left undiluted, it becomes blue of itself, and in less than 24 

 hours the whole becomes cerulin. Any production of sulphu- 

 rous acid which may be observed, is due to impurities ; for when 

 pure, there is no action of that kind by the application of boiling- 

 water heat for some hours. On analyzing the ceruleo-sulphate 

 of potash by oxide of copper, cerulin was found to be composed 

 of 1 atom azote . . 1.75 . . 8.43 



6 oxygen . . 6.00 . . 28.92 



8 hydrogen . 1.00 . . 4.82 



16 carbon . . 12.00 . . 57.83 



20.75 100.00 

 By stopping the action of the sulphuric acid on the indigo, 

 before the formation of cerulin is complete, Mr. Crum obtained 

 what he conceives to be a new and peculiar body, to which he 

 has given the name of phenicin. As soon as the mixture of 

 acid and indigo is become of a bottle-green colour, it is to be 

 diluted with a large quantity of water, filtered and washed. 

 The blue washings which will ultimately be obtained are to be 

 precipitated by muriate of potash, and phenicin will be pre- 

 cipitated, of a beautiful reddish purple colour. It is to be fil- 

 tered and washed, till the washing precipitates red with nitrate 

 of silver ; it may then be dried. 



Phenicin forms blue solutions, both in water and alcohol, 

 but all salts precipitate it purple. It appears to be easily 

 changed into cerulin, by the mere action of water. From the 

 mean of several experiments, 100 of indigo produces 120 of 

 phenicin. Its composition is considered as being, 

 1 atom azote . . 1.75 . . 9.46 



4 oxygen . . 4.00 . .21.62 



6 hydrogen . 0.75 . . 4.05 



, 16 carbon . . 12.00 . . 64.87 



18.5 100.00 



Alcohol remarkably modifies the action of sulphuric acid 

 upon indigo. Three parts of .alcohol, sp. gr. 0.84, with two 



