37 



-also ill strong potasli-ley, wliich sokitioii becomes red at the 

 air, and precipitates tlie salts of the earthy and the heavy 

 metals with red or violet colour. 



CarminiC Aci(l = C28 H14 Oie. Occurs, according to Belhomme, 

 ill the flowers of Monarda didyma. 



Carotill=C3o H24 O2. In the root of the cultivated Daucus 

 Carota. Press the bruised roots and precipitate the liquid with 

 ■diluted sulphuric acid under addition of a little tannic acid. The 

 precipitate, consisting of Carotin, Hydrocarotin and chiefly of 

 •albumin, is pressed, boiled six or seven times, when half dry, 

 ■with five to six times its quantity of alcohol of 80°/o 

 which dissolves hydrocarotin and mannit, and is then exhausted 

 by boiling six to eight times with sulphide of carbon. Distil 

 off the bulk of the sulphide of carbon and mix the residue with 

 an equal volume of absolute alcohol, leave to stand quiet and to 

 crystallise. The crystals of Carotin are washed at first with 

 alcohol of 80°/q, afterwards with absolute alcohol until the 

 latter assumes only a slight yellow tinge. — Dark-red, microscopic, 

 •quadrangular, tabular crystals of velvet lustre and free of water, 

 the latter combining with it below 0° to a colourless, very unstable 

 hydrate, which disunites at a few degrees above 0° ; smells, espe- 

 cially when warmed, strongly like Iris-root, becomes of a vivid 

 red at 100°, similar to metallic copper, fuses at 168° to a thick 

 dark-red fluid, of amorphous structure when cold; is destroyed in 

 higher temperatures, becomes readily discoloured by light and 

 loses completely its faculty of crystallising; does not dissolve in 

 water or in alkalies, scarcely in alcohol, while the amorphous C. 

 dissolves in it; slowly soluble in ether and chloroform, readily in 

 sulphide of carbon, benzol and oils, in concentrated sulphuric 

 .acid with beautiful purplish-blue colour and precipitable from it 

 by water in dark- green flocks as amorphous Carotin. 



Cartliamin or Cartliamic Acid=C28 Hie O14. The red 



pigment of the flowers of Carthamus tinctorius. Exhaust the 

 flowers first with cold water, press out, mix the remaining mass 

 with water containing 15°/^ crystallised carbonate of soda, 

 allow to stand for a few hours, press, neutralise the red alkaline 

 liquid almost completely with acetic acid, throw down the C. on 

 cotton which is left in the liquid for twenty-four hours, wash the 

 cotton with pure water and withdraw the C. from it by macerat- 

 ing in water containing 5°/^ crystallised soda for half an 

 lioiu'. The solution, when mixed with citric acid, throws down 

 the C. in flocks, which must be collected and dissolved in strong 

 .alcohol ; on evaporating the latter solution, the C. subsides. — Dark 

 brown-red, amorphous powder of a green metallic lustre, not 

 volatile, dissolves very little in water with a faint red colour, in 



