606 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



A Test for Gilt. 

 Weber states that a solution of common chloride of copper "will 

 not affect articles covered with gold-leaf, but will leave a brown 

 stain on those covered with gold colored alloys. 



Food for Plants. 

 Mr. Illicnkof, a Rusian chemist, recommends the use of 40 parts 

 of ground bones, 40 parts of wood ashes, and six parts of newly 

 made lime, with water enough to thoroughly mix the whole. 



Perchloride of Iron for Cancer. 



At the Medical Congress of Bordeaux a paper was read by M. 

 Bitot upon the treatment of cancer. The author considers that 

 perchloride of iron {ferramid)is a specific for cancerous affections; 

 its action being like iodine in cases of scrofula; the perchloride 

 should be employed both internally and externally in order to 

 affect both the diathesis and the diseased parts. 



, Photographic Colors. 



A correspondent of the French Repertoire de Photographie, 

 writing from South America, says: " Some time since, I took a 

 positive portrait of my wife on glass. The weather was very fine, 

 but on coming out of my dark room I observed that the light 

 appeared very yellow and somewhat obscured, and I then remem- 

 bered that there was a total eclipse on that day. After develop- 

 ing and fixing my positive I found all the colors of my wife's 

 dress faithfully portrayed on the film. The dress was of blue 

 flowers on a black ground, the cap trimmed with blue and yellow 

 ribbons, and all these colors were accurately reproduced, even the 

 flesh tint of the face and hands were perfect. Unfortunately, all 

 these colors disappeared after a lapse of ten minutes." The writer 

 does not say whether any besides himself saw this portrait of his 

 wife. This is, however, only one of many cases of evanescent 

 coloring reported within a few years. 



Deville's Furnace. 

 M. Deville, of France, has constructed a furnace of grcal 

 beating poAver. It consists of a flame of coal gas, inclosed in a 

 chamber of non-conductors, into which a jet of oxygen gas is 

 blown. In this way only the material required for perfect com- 

 bustion is admitted, thus obviating the objection to the use of 

 oommou air which involves the necessity of introducing into the 



