934 Transactions of tub A^ierican Institute. 



Are Pigeons Opium Proof ? 

 Dr Wier Mitchell, an American pliysiologist, has made the singu- 

 lar discovery that very large doses of black-drop ma}" be given to a 

 pigeon internally, and solutions of sulphate of morphia may be 

 inserted under its skin witliout producing sleep. The last experi- 

 ment made by him seems decisive. To a large pigeon, which within 

 the two preceding days had swallowed forty-two drops of black-drop, 

 he gave, between two p. m. and six o'clock, twenty-one grains of 

 powdered opium, in soft pills of three grains each. Except the 

 usual tendency to remain quiet, none of the common evidences of 

 opium poisoning appeared, and the pigeon was well and active next 

 day. 



A ISTew Thermo-electPvIC Battery. 

 Messrs. Mure & Claymond lately exhibited at the French Academy 

 of Sciences a battery of sixty elements, composed of very small bars 

 of galena and of thin sheet iron, arranged in the form of a hollow 

 cylinder, so as to apply the heat of a gas burner within it to one end 

 of all the bars, precisely the plan followed by other experimenters. 

 The specimen of the battery exhibited was found to have the electro- 

 motive force of one and one-half Bunsen element. M. Bequerel 

 afterward read a long paper on the subject of tliermo-electric bat- 

 teries, in which he expresses the opinion that such batteries, con- 

 structed either of metallic alloys or, as in the specimen exhibited, 

 of a metallic sulphide and a metal, are not economical in use. 

 Besides, they are extremely liable to detrimental changes brought on 

 by heat. 



Artificial Ebony. 

 A material said to be far less expensive than the genuine ebonj'- 

 wood, and capable of receiving a finer polisli, is prepared in the fol- 

 lowing manner : Sixty parts of charcoal made from sea-weeds, are 

 treated with dihite sulphuric acid, and, after being dried, are pulver- 

 ized and mixed with ten parts of liquid glue, five of gutta-percha, 

 and two and one-half of India rubber, the last two having been pre- 

 viously mixed with coal-tar oil to render them gelatinous ; next add 

 ten parts of coal-tar, five of pulverized sulphur, two of pulverized 

 alum, and five of powdered charcoal. The mixture is heated to 300"^ 

 Fahrenheit, and after having been cooled is ready for use. 



