Chemical Science. 403 



them for 24 hours in a mixture of 1 part muriatic acid, and 30 

 water. After being washed, they are to be put into a solution of 

 sulphurous acid, sp. gr. 1034, and left for eight days, during 

 which time, they are now and then to be squeezed. When well 

 bleached, they are to be washed in much water, moistened with 

 orange-flower water, and slowly dried in the air. — Journ. de Phar. 

 X. 499. 



30. Cholesterine in human Bile. — The existence of biliary calculi, 

 composed entirely of cholesterine, induced M.Chevreul to ascertain 

 whether bile did not always contain that principle. He ob- 

 tained it by the following process. The bile, after having been 

 diluted, filtered, and concentrated, was precipitated by alcohol ; the 

 alcoholic extract was acted upon by ether, and the latter solution 

 left to crystallize spontaneously : a substance separated, which, 

 when purified, was neither acid nor alkaline to vegetable colours, 

 which like cholesterine crystallized, either when fused and cooled, 

 or when dissolved in alcohol or ether. It required above 212° for 

 its fusion, was not saponified by being boiled for 24 hours in solu- 

 tion of potash ; in contact with sulphuric acid, instantly became of 

 an orange red colour ; and with nitric acid, behaved like cholesterine. 



This cholesterine was from bile obtained from the body of a man 

 who had died suddenly by a fall from a third story. Cholesterine 

 was also found in the bile of eight other persons of different sexes, 

 age, and who had died of different diseases, all contained also va- 

 riable quantities of margaric and oleic acids. 



All the biles examined, furnished the red substance, which had 

 been first observed in the serum of the blood of infants attacked by 

 jaundice and induration of the cellular tissue. This substance is in- 

 soluble in cold water, and nearly insoluble in alcohol and ether. It 

 it very soluble in solution of potash ; the solution has an orange 

 colour, which by contact of oxygen changes, passing by yellow 

 and yellow green. Nitric acid renders it blue, purple, red, and 

 then yellow. Concentrated sulphuric acid makes it yellow, green, 

 and at last blue, resembling indigo. It is considered, that the sub- 

 stance described is a colourijig matter in a state of purity. 



The bile of a bear gave a notable quantity of cholesterine, as well 

 as of margaric and oleic acid. The bile of a pig gave a portion of 

 what seemed to be cholesterine, and a greasy substance which 

 appeared to be margaric and oleic acid. — Mem. du Mmeum, ii. 

 239. 



31. Electrical Conducting Power of Melted Resinous Bodies. — It 

 is commonly stated, that melted resins become good conductors of 

 electricity, and freely allow of its transmission. The following 

 experiments were made witli the view of determining to what extent 

 they possessed this property. 



Common resin, shell-lac, asphaltum, bees'-wax, red and black 



