312 Scientific Intelligence. 
not fewer than something like a unit-eighteen of molecules” [i. e. 
1,000000,000000,000000] “in each rie creeper ~ a gas at 
ess H 
177 ate 305, I phe an obiaateien of the daeiahndcieasll aioe 
within Crookes’s radiometers based upon this very 2 seem ent ee 
see in oe page 17 8, where co following words r:—“I 
what we know of the number of molecules in gases at ordina 
pipers that the number remaining in this so-called vacuum will 
be somewhere about a a i. e. one hundred millions of 
millions, in every cubic millimeter.” After which I quote, in 
besa was new ‘to mself, and had been overlooked a some of 
the writers upon Gisokeas radiometer.— Phil. Mag., Sept. 1877, 
8. Note on the Telephone ; by Pacer Hiees.—In the present 
agitation concerning speaking or telephonic telegraphs, the follow- 
ing extract from M. Le Comte du Moncel’s “ Exposé des Applica- 
tions de l’Electricité,” edition of the year 1857, vol. iii, p.110, may 
be atid as pointing out how nearly the ‘idea has been fore- 
_ 
“ The Electric Transmission o ech,—I did not wish to bring 
forward in the chapter of the electric telegraph a fantastic concep- 
tion of a certain M. Ch. B——, who believes that it will be possible 
— transmit speech electrically, because it might have been asked 
had classed among so many remarkable inventions an idea 
mint presented by the author as it is, is not more than a dream. 
However, to be faithful to the réle that I have imposed upon my- 
self of speaking of all the oo of electricity that have 
become known to me, I wish to quote here the information which 
the author has pu ublished on this subject. 
‘ After the marvelous telegraphs which are able to reproduce at 
a issanoe writing of this or that individual, and designs more or 
