52 Scientific Intelligence. 
fact that it cannot exceed 45 makes it certain that the molecule 
of potassium in vapor consists of two atoms.— Proc. ps y- in 
Xxi, 143, for 1873. 
2. On the Ei ‘ydrocarbons produced by the solution of, easton 
in vids — n the November number of this Journal, Mr. F. H. 
Williams communicated some results of his examination of the 
S cisaxbons evolved on treating cast-iron with acids. We have 
received a letter recently from Mr. . Hann, now ‘of Wyandotte, 
Michigan, ealling attention to the fact that he made a similar in- 
A cans eee in 1864, the results of which were published in Liebig’s 
Annalen. e portions of the evolved gases which were absorb- 
able by fuming sulphuric acid or bromine—amounting in the case 
of white iron to 1°26—1°6, and in the case of gray iron to 0°36—0°28 
per cent by ee sented of ethylene, ae , butylene, 
amylene and caproylene, as was proved by the b oiling points, the 
composition and the other properties of their bromides. Acety- 
lene was not detect — The gases not thus absorbable, which were 
between 110° and 290°. There separated out also, from the ferrous 
sulphate solution, on treatment with water, a disagreeably smell- 
ing oil, which, by access of air or by treatment with chlorine wa- 
ecame: br own and resinous. e dry residue of the iron, in- 
A sulphur product was also observed. It is a noteworthy fac 
t in Mr. My illian 
grt —Ann. Che em, Pharm., exxix, 57, 1864. 
On the Optical properties of Cenc som differen ent sources. 
acted psTONE has submitted to examination eight specimens of 
cymene ° obtained by Wright from widely different sources. The 
following are the results obtained : 
