1816.} during the Year 1815. 55 
alcohol, sulphuric ether, oils, lime-water, and distilled vinegar. 
It dissolves in potash and ammonia by the assistance of heat,fand is 
again precipitated by acids. Sulphuric acid dissolves it and black- 
ens the colour. Muriatie acid produces the same change of colour; 
but forms only an imperfect solution. Nitric acid dissolves it, and 
changes its colour to reddish-brown. 124 grains (124 Troy grains) 
of the pigment were subjected to heat in a glass tube; a few 
drops of water came ever, holding carbonate of ammonia in solu- 
tion, a brown oil, and crystals of carbonate of ammonia. The 
gas extricated amounted to six cubic inches (6°17 cubic inches 
English) which consisted of 
Oarlionic acid aS. ois es ea oes 3 
Oxygen vas wc... e cece ests eee enes 0°159 
Azotic gas..... Soe ahh ete Saal AN SL i MBB 
Carbureted hydrogen ..... Hepes we a 0-710 
6-000 
The water, oil, and carbonate of ammonia that came over into 
the receiver weighed five grains; and the oil alone amounted to 
1 of the weight of the whole. The coal remaining in the retort 
weighed 51 grains. It consisted almost entirely of charcoal. 
When burnt it left ~ths of a grain of ashes, which consisted of 
soda, lime, oxide of iron, and muriatic acid; and probably, also, 
phosphoric acid and carbonic acid. Gmelin conceives that this 
black pigment approaches the nature of indigo. 
3. Ink of the Cuttle Fish—Some experiments on this substance 
were published in 1813 by Mr. Grover Kemp. Dr. Prout lately 
analyzed a quantity of it in a dry state, which had been sent him 
in the original cyst in which it was contained. He found 100 
parts of it to be composed as follows. (Annals of Philosophy, 
vol. v. p. 419.) 
Black colouring matter........+++++ 78°00 
Carbonate of lime........ sgc.0e mise c, LeraO 
Carbonate of magnesia........ thee tot ay ls 
Muriate of soda? 2-16 
Sulphate of soda? § “"""*"""*" oer 
TUTOR 5505 0's, «64m <r us en, bi ‘Dire Piri Ped io 
RRS A aac teria 1°60 
100-00 
Dr. Prout did not particularly examine the colouring matter; 
but this has been done by Leopold Gmelin, who found it to possess 
very nearly the same properties with the black pigment of the eye. 
(Schweigger’s Journal, vol. x. p. 533.) His experiments do not 
quite agree with those stated by Dr. Prout ; probably, because they 
were tiade upon the recent and moist pigment, whereas Dr. Prout’s 
experiments were made upon it in a dry state. 
4. Milt of the Cyprinus Tinca, the Tench.—Foureroy and Vau- 
quelin published some years ago a set of experiments on the milt of 
