1012 Tfaxsactioxs of the American Institute. 



it, wliieli, as is well known, imparts to the gas in the thick part a hlne 

 color, tinged with violet, and in the capillary portion a brilliaTit red. 

 ISTow, if the latter be placed between the poles of the electro-magnet, 

 the red at once disappears, and is converted into white light. In the 

 case of oxygen, the capillary part is milky white ; nnder the influence 

 of electro-magnetism it becomes red. Under the same circnmstances 

 the l)lne of nitrogen becomes much darker, and the sparkling M'hite 

 of carbonic acid turns blue. Hence, so far, magnetism is found to 

 destroy or change the color of a gas in the capillary part of a tube 

 containing it. 



Another Laege Telescope. 

 Messrs. Cooke & Son, of York, Eng., have just completed a tel- 

 escope thirty-two feet long, having an object glass tweny-five inches 

 in diameter. No report has reached us regarding its power and 

 quality. It was made for Mr. ISTewall, submarine cable manufacturer, 

 of Gateshead, who intends to erect an observatory for its accommo- 

 dation at Madeira.. 



"Watee-proof Packing Paper. 

 This paper is prepared by coating it with a resinous liquid, and 

 afterward painting it with a solution of glue and soot, to prevent the 

 appearance of blotches. After it is dry the true water-proof coating- 

 is applied, which consists of a solution prepared with two and a half 

 ounces of powdered shellack to two pints of water ; to this, M'hile 

 hot, is added gradually one-tliird of an ounce of pulverized borax ; 

 at the same time, mineral coloring matter, like ochre or umber, may 

 be added. When cold it is ready for use. The operation of coating 

 is so quickly performed that two persons may prepare 3,000 square 

 feet of paper per day. 



Spectrum or the Fire-fly. 

 Mr. C. A. Young has described in the American Naturalist the 

 spectrum given by the common tire-fly as being perfectly contin- 

 uous, without trace of lines, either bright or dark, and extending from 

 n little above Fraunhofer's line C in the scarlet to about F in the 

 blue, gradually fading out at the extremities. It will be observed 

 that tliis portion of the spectrum contains the most luminous rays, 

 the calorific and actinic rays not being brought materially into play. 

 This insect, therefore, has the power of generating onl}- those undu- 

 lations whose velocities are such as to affect most powerfully tlie organ 



