Scientific Intelligence, Sfc, 231 



the wood of this plant, when treated with alcohol, gives a resin with 

 an aromatic odour. 2. When the alcohol is distilled, the resin is 

 found to be mixed with a liquid like coffee and milk, which, when 

 evaporated, forms an extract, which, when melted with the peculiar 

 resin, forms a homogeneous substance. 3. The white liquor re- 

 .maining in the alembic contains a bitter principle of an oily con- 

 sistence held in suspension by the gummy extractive matter. If this 

 be made into a paste with magnesia, and distilled from a glass retort, 

 a limpid aromatic liquid comes over. Dividing the caput mortuum 

 by means of pure water, and in decomposing by dilute sulphuric 

 acid, sulphate of magnesia is formed, and a white substance is 

 deposited, which, when dissolved in alcohol, and evaporated, forms a 

 body susceptible of crystallizing in needles. The author terms this 

 substance Guaiacic acid, which is quite distinct from benzoic acid, 

 4. The brown resin of guiac, when heated in a retort on hot coals, 

 assumes a red appearance, and disengages an oily fluid, possessing 

 the taste and smell of creosote. When purified, it constitutes the 

 creosote of Reichenbach. — Journ. de Chim. Medic, July, 1836. 



6. Pellitory Root (Pyrethrum.) — According to Koene, this 

 root, when subjected to successive treatment with ether, alcohol, 

 cold and boiling water, afforded, 1st, a very acrid brown resinous 

 substance, insoluble in a solution of caustic potash 0'59. 2nd. A 

 fixed oil of a deep brown colour, acrid and soluble in potash 0-60. 

 3rd. A yellow oil, acrid, equally soluble in potash 0-35. 4th. Traces 

 of tannin. 5th. Gummy matter 9-40. 6th. Inulin 57-70. 7th. 

 Sulphate, muriate and carbonate of potash, phosphate and carbonate 

 of lime, alumina and silica, oxides of iron and manganese 7*60. 8th. 

 Woody matter 19-80. 9th. Loss2-6. — Journ. de ^ha7'm., Feb. ,1836. 



7. Creosote. — Koene has succeeded in obtaining a large product 

 of this substance from coal-tar. He distils the tar in a retort 

 supplied with a large wide beak, under which he places a capsule. 

 At first, a light oil comes over, but by changing the receiver 

 from time to time, a heavy oil is obtained ; the distillation is con- 

 tinued, elevating the temperature until the naphthaline is condensed 

 in the neck of the retort. A certain quantity of creosote remains 

 in the beak united to the naphthaline ; the product falls into the 

 capsule on applying heat. It is then exposed to a cold mixture, and 

 the naphthaline taken up by expression. To obtain the whole of 

 the creosote, the expressed naphthaline is heated with its weight of 

 pyroligneous acid until it melts. On cooling, the naphthaline crystal- 

 lizes, and may be separated by pressure from the liquor, which is 

 then saturated with sub-carbonate of potash. The heavy oils obtained 

 are treated successively by -Mh of their weight of phosphoric acid, 

 and by an equal volume of water. It is then rectified. The pro- 

 duct is dissolved in potash, and the free creosote isolated by a slight 

 excess of dilute phosphoric acid. It is again rectified, the water 

 separated, and pure creosote obtained. — Ibid. 



III. — Impurity of Zinc and Sulphate of Zinc, 

 WiTTSTEiN found in the zinc of commerce at Munich, zinc 98*76, 

 lead 0-91, cadmium 0*16, iron 0-17. The sulphate of zinc, he found 



