408 Correspondence of J. Nickles. 
I may take occasion to reproduce these facts which were at first 
strongly contested, although now admitted, and which a German chemist 
has recently brought out with some variations,* leaving it to be supposed 
that nothing had been done on the subject before. 
wo communications have been ma y M. Dumas on these phys- 
ico-chemical questions. Not being able for want of room to speak of 
them with detail, I will restrict myself specially to that one which has 
not been published in the Comptes Rendus, but which M. Dumas pre- 
have their extremities in this same straight line parallel to that of the 
alcohols to which they are related, and the prolongation of the line for 
the acids ends at the summit of the ordinate corresponding to the atomic 
genated water HO?. 
As to the ethers of different acids and alcohols: the lines for the 
ethers of the same base but of different acids are parallel to the lines of 
the alcohols and acids; but for ethers of the same acids and of different 
bases, they are parallel to one another, but not to those of the alcohol 
and acids. The line of the nitric ethers meets the place of hydrated 
nitric acid; that of the sulphuric ethers passes by the point representing 
ydrated sulphuric acid: the summit of the ordinate corresponding to 
liquid sulphuretted hydrogen is in the line of mercapton and its homo- 
logues. In fine, then, on producing the line of the ethers of the same 
acid » you always meet the point of the hydracid or hydrated acid corres- 
ponding. -~ 
The line of the aldehyds is parallel to that of the alcohols; it's 
however a little less elevated. The acids and the alcohols of the same 
series are united by lines almost parallel to the axis of the abscissas- 
The lines which unite the places of the compound ethers, the simple 
ethers, and the anhydrous acids, are straight, as well as those which unite 
together the alcohols and the hydrated acids; but the ether and its al- 
cohol, the compound ether and anhydrous acid, are sinuous lines and 
very irregular (tres accidentées). The above are the principal facts 
flowing from the researches which M. Dumas presented in an eloquent 
manner before a most distinguished and attentive audience. : 
Limits of the vaporization of Mercury.—Till now it has been 
admitted with Faraday that the vaporization of mercury is very im 
* Annalen der Chem. u. Pharm. Aug, 1854. 
* 
