978 TEAXSAC'hoXS OF THE AMERICAN InSTITVTE. 



seventy-one potatoes quite sound and fifteen diseased. In 1867 he 

 planted the diseased potatoes and a few sound ones, sntlicient to 

 make a long row ; the result was scarcely any disease at all. In 1868 

 he planted two rows, talcinpj all the diseased and small potatoes ; the 

 result was a good crop, and no disease. On the 21st of April, 1869, 

 he looked over the potatoes left, about half a bushel, and could not 

 find a trace of disease. 



ISTeav Process foe Extracting Copper from its Ores. 



Dr. T. Sterry Hunt and James Douglass Jr., have invented a pro- 

 cess for separating copper from such of its ores as are in the state of 

 an oxyd or semi-compound thereof, as oxychorid or carbonate of cop- 

 per. They claim : 1. The use of a solution of neutral protochlo- 

 ride of iron, or of mixtures containing it, for the purpose of com^ert- 

 ing the oxyd, or suboxyd of copper, or their compounds, into chlo- 

 rides of copper. 2. The use of sulphurous acids for the purpose of 

 decomposing the oxychloride of n-on formed in the preceding reaction. 

 3. The use of a process for the purpose of extracting copper from its 

 naturally or artificially oxydized compounds by the aid of the first, or 

 the first and second of the above mentioned reactions. 



In relation to this item Professor Stevens said, that nine-tenths of 

 the copper ores of the United States, were of inferior grades. 



Curative Properties of Petroleum. 

 A London medical journal reports a number of cures in East 

 Indian hospitals by the application of petroleum in combination with 

 other materials, to form a consistent ointment. Petroleum is found 

 to take the place of carbolic acid as a local disinfectant. It has been 

 successfully used, also, by American physicians, and has long been 

 sold in this country as a " patent medicine " under various names. 



Mucilage. 

 A preparation is now used in England, on what are called " safety 

 envelops," which is made from thick, tough sap found in large quan- 

 tities in the leaves of the New Zealand flax. 



New Actinometer. 

 Bunsen and Po^co have prepared a paper of standard sensitive- 

 ness which varies in tint exactly in proportion to the length of time 

 it is exposed to ligtit. Such paper can be used in countries where 



