Polytechnic Association Proceedings. 1005 



strained. While yet warm it is spread with a camel's hair brush 

 upon paper previously coated with a thin solution of glue or gelatine. 

 The paper, on being dried, presents a beautiful crystaline sur- 

 face. The size of the crystals may be varied by altering the 

 strength of the solution, and by drying the paper more or less 

 rapidly. Crystals of different tints may be made by mixing ana- 

 line colors with the solution, and preparing the paper with the 

 white of eggs instead of gelatine. 



NEW ALLOYS OP LEAD AND TIN. 



M. Plho describes two new alloys containing less tin than ordi- 

 nary pewter, which are not acted upon by boiling acetic acid or by 

 salt water, and may therefore be used for some kinds of utensils. 

 The first alloy contains 1 part of tin and 2.4 parts of lead. It has 

 a density of 9.64 and melts at 320 degrees Fahrenheit. I-t is made 

 by first melting the lead, and, after skimming it, gradually adding 

 the tin; by stirring it constantly with a wooden stick in the mean 

 time, the lead is prevented from settling to the bottom. The second 

 alloy consists of 1 part of tin with 1.25 of lead. It is less malle- 

 able and more brittle than the first. 



THE COlVnNG ECLIPSE. 



Both English and French astronomers are making preparations 

 for observing at the East an eclipse of the 'sun on the 18th of 

 August next, which will be total for the space of six minutes forty- 

 six seconds along a line passing through Southern New-Guinea, 

 Hindostan, the Bay of Bengal, the Malayan Peninsula, and the Gulf 

 of Siam. Leverrier recommends that the French ships be placed 

 on the eastern side of the Malayan peninsula for the accommo- 

 dation of the observers. Some interesting questions regarding the 

 "corona" and" red flames," it is hoped, will then be satisfactorily 

 settled by means of the spectroscope. 



ANOTHER ASTEROID. 



On the I7th of February, M. Borelly of the Observatory at 

 Marseilles, France, discovered a telescopic planet, which isihe 96th 

 of those now known, having orbits between Mars and Jupiter. 

 Three nights later it was observed by M. Loewy with the great 



meridian instrument at Paris. 



/ 



CURE FOR THE CATTLE PLAGUE. 



• Chloride of copper is now extensively used in Germany against 

 the cattle plague. The practice is to dissolve eight grammes of 



