296 Intelligence a?id Miscellaneous Articles, 



deviations. The amalgam above-mentioned produces this i)haeno- 

 menou exceedingly well. If the amalgam, although still capable of 

 becoming solid, loses its property of crystallization from the presence 

 of a lai'ger proportion of mercury, the phsenomenon no longer takes 

 place. 



We obtain the same phaenomenon with antimony. One might 

 be inclined from this to conclude that thermo-electric currents take 

 place only on solid metals, especially since it appears to be well de- 

 monstrated that it is by the effect of a chemical action that the 

 contact of hot water with cold develops electric currents. — Biblio' 

 thcque Universelle, November 1837. 



ON CETRARIN. BY M. HERBERGER. 



This name of cetrarin is given to the bitter principle of the cetra- 

 ria or liverwort. M. Herberger first procured this product ; the pro- 

 cess by which he obtained it is as foUoM^s : boil coarsely-powdered 

 liverwort in four times its weight of alcohol, of specific gravity '883 

 for half an hour, and let it remain ; in order that no alcohol may be 

 lost, it is strained and pressed ; to this liquor there is to be added, 

 for each pound of liverwort employed, three drachms of hydrochloric 

 acid, which is to be diluted with four times its bulk of water ; the 

 mixture is to be allowed to remain for twelve hours in a stopped 

 glass vessel ; the supernatant liquor, of a deep yellow colour, is then 

 to be poured oiF from the abundant deposit formed ; this is impure 

 cetrarin, and is of a green colour of greater or less intensity. It is to 

 be collected on a strainer, and when it ceases to drop, it is to be 

 pressed. 



Cetrarin is to be purified by separating it into small portions, and 

 washing it while moist with alcohol or with aether, which deprive it 

 of its colouring matter ; it is afterwards to be treated with twice its 

 weight of boiling alcohol, which dissolves it, and allows it to preci- 

 pitate on cooling. A further quantity may be obtained by evapo- 

 rating the alcoholic solution. 



Cetrarin is sometimes a white powder resembling magnesia, and 

 at other times it is in small globules united in the form of arboriza- 

 tions, which exhibit no appearance of crystallization, even when ex- 

 amined by the microscope. When pressed it has a silky lustre ; it 

 is light, unalterable in the air, inodorous, with a decidedly bitter 

 taste ; it is not entirely fusible ; it begins to become brown at 257° 

 Fahr. At a higher temperature it yields a reddish-yellow acid oil, 

 which becomes solid at 320" Fahr. It then blackens and leaves a 

 great quantity of light charcoal, which burns readily in the air. It 

 is soluble in boiling absolute alcohol, 100 parts of which take up 

 1-70; at 60° it dissolves only 0-28. 



The use of cetrarin in medicine is but recent, and it is impossible 

 to say how far it may be employed ; it has, however, been exhibited 

 as a febrifuge. The formula being, 



Cetrarin 2 grains. 



Gum arable .... 2 grains. 

 Sugar 12 grains, 



