Polytechnic Association Proceedings, 599 



bismuth and phosphoric acid. 



When a piece of bismuth is thrown into a solution of glacial 

 phosphoric acid, the metal fuses to a bright globule, from which 

 small flames appear. This action is sometimes so strong, that par- 

 ticles of incandescent bismuth are thrown out of the vessel, thus 

 forming a shower of sparks. The flames which appear, evidently 

 arise from the phosphate of bismuth which would be formed, and 

 which is decomposed by its release of phosphorus, or forming phos- 

 phretted hydrogen in contact with the water of the constitution of 

 the phosphoric hydrate. Eventually there remains a spongy mass 

 of bismuth, as well as a white powder, which is phosphate of 

 bismuth. 



ELECTRIC LIGHT FOR SHIPS. 



The electric light has been used on the French yacht, Jerome 

 Napoleon, for the purpose of ascertaining whether it will mate- 

 rially aid in avoiding collisions at sea. Beside the ordinary 

 reflecting apparatus, it is proposed to try the light condensers, 

 first used by M. Louis d'Henry in solving the following problem: 

 " Being given a luminous point to contrive an apparatus which 

 receives on its surface all the light emanating from that point, and 

 directs it toward a position in space." The apparatus to be used 

 on the yacht, consists of an ellipsoid of revolution, by means of 

 which the light placed in one of the foci undergoes three reflec- 

 tions, and is projected sixteen times more intense than the direct 

 peucil of rays. 



Prof. Vanderweyde said, the electric light was first used in this 

 country, and on the Collins line of steamships about ten years ago. 

 The magnets required to produce this light were revolved by a 

 small engine of six horse power; but the experiment was not 

 regarded as satisfactory. 



SEPARATION OF NAPHTHALINE. 



Dingier' s Journal describes a mode of eflfecting more perfectly 

 the sublimation of naphthaline, a substance which clogs up gjis 

 pipes, and has thus far brought little profit to gas makers. The 

 crude product, consisting of small brown crystals with tarry mat- 

 ter, is thoroughly mixed with twice its volume of fine quartz sand. 

 This mixture is placed over a water bath in a layer about four 

 inches deep, and covered with a cloth. Above the whole is a light 

 box, made either of wood or paper, in which the volatile product 

 is condensed. Under one hundred degrees C, naphthaline slowly 



