Intelligence and Miscellaneous Articles. 477 



because the hydrochloric acid in its turn destroys the hypochlorous 

 acid, and regenerates chlorine : this arrangement will be seen by 

 reversing the two members of the equation, 



2C1+H0=C10 + HC1, 

 C10 + HC] = 2Cl+HO. 



The hydrochloric and hypochlorous acids can coexist only in the 

 presence of a large quantity of water ; the author proved this by 

 direct experiment. 



M. Millon is of opinion, that the very simple molecular relation 

 existing between water and hypochlorous acid ought to be extended 

 to the chloride of sulphur, which belongs to this system of sulphu- 

 retted hydrogen, of which chlorine has replaced the hydrogen, equi- 

 valent for equivalent. It will be seen by this arrangement, that the 

 most chlorinated chloride of sulphur will contain two equal equiva- 

 lents of chlorine and of sulphur. Thus it will be in vain, as chemists 

 well know, to attempt to combine more than one equivalent of chlo- 

 rine with one equivalent of sulphur ; on the contrary, it is easy to 

 combine several equivalents of sulphur with one equivalent of chlo- 

 rine. The polysulphurets of hydrogen then come under considera- 

 tion, and the following symmetries result : — 



HO, HS, HS W 



CIO, CIS, CIS 71 . 



Ann. de Chim. et de Phys., Aout 1850. 



ON THE DISCOLORATION OF SILVER BY BOILED EGGS. BY 

 M. GOBLEY. 



It is observed by the author as a well known fact, that silver, 

 when brought into contact with eggs which have been heated, is 

 blackened ; this discoloration is owing to sulphuret of silver. It is 

 usually admitted that this sulphuret is formed by the action of the 

 sulphuretted oils supposed to exist in the yolk of the egg ; not having 

 found in this body anything of this nature, M. Gobley thought it 

 would be interesting to examine into the cause of this phenomenon. 



Yolk of egg at common temperatures and when gently heated, 

 does not discolour silver, even by contact of several hours' duration. 



Albumen as procured from the egg, does not tarnish silver, but 

 when the temperature is raised, it gives it a brown tint, which is 

 stronger as the heat is greater. 



The discoloration of the silver is then due to the sulphur con- 

 tained in the albumen, and not to that supposed to exist in the oil 

 of the egg ; but is the sulphuret formed under these circumstances, 

 the result of the immediate action of the sulphur upon the silver, or 

 by the application of heat do the sulphur and the alkali of the albu- 

 minous matter react upon each other, so as to form a substance which 

 is afterwards decomposed by this metal ? 



The following experiments induced the author to adopt the second 

 of these opinions : — 



1 . Paper impregnated with lead, when exposed to the vapour dis- 

 engaged from the heated albumen, is not sensibly discoloured. 



