CERIUM. 



CHEMISTRY. 



99 



clearances, 67 vessels (8 English, 8 German, 

 3 French, etc.), of about 69,000 tons. On 

 September 23, 1867, the port of Lomon, on the 

 Atlantic side, was also opened to commerce. 



CERIUM. M. Wohler has published an ac- 

 count of his researches on cerium. He obtain- 

 ed the metal by the following process : A solu- 

 tion of the brown oxide of cerium in hydro- 

 chloric acid was mixed with an equivalent 

 quantity of chloride of potassium and of chlo- 

 ride of ammonium, and the whole evaporated to 

 dryness. The mass was then transferred to a 

 platinum crucible, and heated till the whole of 

 the chloride of ammonium was volatilized and 

 fusion obtained. The fused mass was poured out 

 and mixed, while still warm, with fragments of 

 sodium, and introduced into an earthen cru- 

 cible previously heated to redness. When the 

 contents had again fused, and the excess of 

 sodium volatilized, the crucible was removed 

 from the fire ; the deep-gray resulting mass 

 was filled with little metallic globules. In a 

 second experiment a large piece of sodium was 

 thrown into a red-hot crucible containing chlo- 

 ride of potassium, and then the coarsely-pow- 

 dered chloride used before. In operating in this 

 way, a larger proportion of metallic globules 

 was obtained, some of which weighed 50 to 60 

 milligrammes. These metallic globules appear 

 to consist principally of cerium. The color of 

 the metal is intermediate between the color of 

 iron and that of lead. The metal is lustrous 

 when polished ; it is malleable. Its density is 

 about 5.5 at 12. Exposed to the air, it loses 

 its lustre, and becomes slightly blue. It feebly 

 decomposes water at 100. Hydrochloric acid 

 dissolves it with energy; concentrated nitric 

 acid converts it into clear brown oxide, and the 

 dilute acid dissolves it. By evaporation, a white 

 salt is obtained, which leaves, after calcination, 

 a brown oxide, insoluble in nitric acid and in 

 dilute sulphuric acid. Concentrated sulphuric 

 acid slowly dissolves this oxide, forming a yel- 

 low solution which shows the reactions of eerie 

 salts. Hydrochloric acid dissolves this oxide 

 with disengagement of chlorine, forming a 

 colorless solution. When a globule of cerium 

 is heated by the blow-pipe to dull redness, the 

 metal inflames and burns vividly, forming 

 brown oxide ; but, upon submitting a globule 

 suddenly to a very high temperature, it burns 

 with explosion, sending out bluish sparks. 

 Cerium powder can inflame below 100. When 

 the saline mass containing the cerium globules 

 is treated with water, a fetid hydrogen gas is 

 liberated, and a brilliant powder of a deep 

 purple color is deposited, which is easily sep- 

 arated by washing. Dilute hydrochloric acid 

 extracts from this powder a small quantity of 

 metal, as well as of oxide. This body is a 

 cerous oxychloride. Concentrated hydrochlo- 

 ric acid attacks it with difficulty ; concentrated 

 nitric acid dissolves it, forming a colorless so- 

 lution. 



CHEMISTRY. The Artificial Formation of 

 Organic Substances. Mr. C. G. Williams com- 



municated to the Royal Institution of Great 

 Britain in May, 1868, a brief history of the 

 progress made by chemical science in the arti- 

 ficial formation of organic substances. He 

 showed that Wohler's synthesis of urea was 

 one of the earliest in point of date, and his 

 method was described, and also Kolbe's new 

 process, by the mere heating of ammonic car- 

 bonate to a point just below that at which 

 urea is decomposed. The conversion of car- 

 bonic disulphide into carbonic tetrachloride or 

 perchlorinated marsh-gas was another exam- 

 ple of true synthesis. So was the production 

 of oxalic acid by the direct union of carbonic 

 anhydride and sodium, recently accomplished 

 by Dr. Drechsel; and it was shown that, as 

 oxalic acid by distillation yields formic acid, 

 the synthesis of the first acid leads directly to 

 a new synthesis of the second. Allusion was 

 made to Berth elot's process of making formic 

 acid by heating potassic hydrate in an atmos- 

 phere of carbonic oxide, and Kolbe and 

 Schmidt's method of making the same sub- 

 stance by exposing potassium to a warm atmos- 

 phere of carbonic anhydride. The manufac- 

 ture of acetic acid from carbonic bisulphide 

 and the chlorides of carbon, of acetylene by 

 several processes, of succinic acid, of tartaric 

 acid, and of organic alkaloids, were succes- 

 sively described and illustrated by experi- 

 ments. The author said that one of the most 

 interesting of the cases of synthesis recently 

 accomplished was that in which Mr. W. H. 

 Perkin had succeeded in producing artificially 

 the odoriferous principle of new hay and the 

 Tonquin bean. The delicious fragrance of new 

 hay is entirely due to the presence of the 

 sweet-scented vernal grass, Anthoxanthum odo- 

 ratum. It is the same substance which is the 

 cause of the sweet smell of the woodruff, Aspe- 

 rula odorata; and the melilot, Melilotos offici- 

 nalis. It is also the flavoring ingredient in the 

 Maiwein of the Germans, which is perfumed 

 with woodruff. Until lately, nothing was 

 known about coumarin, except that it was a 

 colorless crystalline body, having the formula 

 C9H 6 2 . The crystals of coumarin appear 

 very beautiful under the influence of polarized 

 light. The image of some artificial coumarin, 

 which had been fused and allowed to crystal- 

 lize in a plate of glass, was then thrown upon 

 the screen, and, the light being polarized by 

 the aid of Nicol's prisms, the crystals assumed 

 the most gorgeous and varying colors as the 

 prisms were rotated. The clew to its constitu- 

 tion was shown to be the circumstance that 

 when heated with potassic hydrate it yields 

 salicylic and acetic acids. The production of 

 salicylic acid from coumarin was then shown 

 experimentally, the presence of the acid being 

 proved by its yielding a deep-purple coloration 

 with ferric chloride. Artificial coumarin was 

 obtained from the hydride of salicyl. By 

 treatment with sodium it yielded hydride of 

 sodium-salicyl ; this substance, heated with 

 acetic anhydride, gave hydride of aceto -salicyl. 



