254 Scientific Intelligence. 
upper. When this is the case, the ‘action of the current in the 
helices raises the bar from off its rest below, the pivot being 
however retained within the socket to keep the bar in place. 
Play enough should be given in the socket above, to allow the 
bar to rise. ‘The friction being thus very much diminished, the 
extra friction of the solid, over the mercurial connexions, is more 
than compensated. 
Washington, D. C., Jan. 25, 1847. 
SCIENTIFIC INTELLIGENCE. 
J. CHEMISTRY AND Puysics. 
1. On a Common Origin of the Acids (CH)nO, with a boiling 
point below 300° Cesiarads i ; by Dr. Jos. Reprensacuer, (Phil. Ma ag. 
omposed of a hydro-carbon, which isa multiple of CH, and four 
equivalents of oxygen. To this group of homologous acids belong the 
acetic, valerianic, and the volatile acids of butter, in which 2 is always 
some multiple of 2. This increase in the value of the factor is at- 
tended with a regular increase in the boiling point of the acid. 
cording to the late researches of Kopp and Fehling, it equals 20° C. 
when the value of nm is augmente 
It is probable that all these acids inay be produced from bodies like 
aldehyde of the formula (CH)nO,, by a simple process of oxydations : 
This has been already established with regard to the acetic, metacetonic, 
butyric, valerianic, and enanthylic acids. 
r. Redtenbacher has examined the volatile acids which result from 
the action of nitric upon oleic aci oleic acid was boiled in a retort 
with an excess of strong nitric acid till all oily matter eas ea Wa- 
ter was then added and the mixture distilled. The product collected in 
the receiver consisted of a stratum of the oily acids and a watery solution 
the more soluble ones. The oily portion was neutralized by baryta 
and the different salts separated by crystallization. The aqueous solution 
contained acetic, metacetonic, and butyric acids, and an examination of 
the baryta salts showed that not less than nine acids had been formed, 
of the type (CH)nO, ; the value of the factor being nogenue by 2 
from 4 to 20, and the boiling point rising from 120° C, to 280° C. They 
were the acetic, pepe Poles valerianic, ai gee 
caprylic, pelargonic, and ca e metacetonic acid is obtained by 
the action of potash on ates, yer by the oxy dation of metacetone (an 
aldehyde) ; the butyric, caproic, caprylic, and capric, are known as s the 
volatile acids of butter, and the pelargonic acid is so named from its 
supposed identity with a fatty acid, discovered by Pless in the rose gera- 
nium, Pelargoniun roseum 
This origin . the volatile fatty acids gives a key to the mode of 
their for nature. The experiments of the author and others 
