656 DEVELOPMENT OF MUSCULAR FIBRE IN MAMMALIA. 
completely industrial processes, but that they have also 
secured to science the possession, at a very moderate price, 
of a reagent of the highest importance — sodium. 
Indeed, this metal, which rivals potassium in energy, does 
not present, in its preparation or management, any of the diffi- 
culties which the latter would present. The numerous trials 
made, prove that its extraction is as easy as that of zinc ; that 
it may remain in contact with the air, in full fusion, without 
inflaming; finally, that it may flow from the first jet of the 
continuous apparatus used for preparing it. Its preparation 
is as easy as that of lighting- gas. 
Such an agent as that of sodium, put at a moderate price 
at the disposal of the arts, will not remain long without taking 
a large part in them ; this is certain. 
The Academy -will likewise remark, that the labours at the 
manufactory of Javel open up a new path to metallurgical 
industry. Hitherto, the metals utilised were native metals, 
or metals liberated by modes of treatment which consisted 
always, definitively, in reducing their oxides with charcoal. 
The extraction of aluminium in this large way opens then a 
new way, since it teaches us that we may extract the metals 
from their chlorides. For certain metals this process is in- 
dispensable ; for others, the old methods may be preferred. 
Certain metals, unknown to industry, may be brought within 
its domain. 
M. Dumas concluded by calling the attention of the 
Academy to the sonorousness of aluminium, which might be 
campared, in this respect, to the most sonorous bronzes — to 
those of bells, for example — a quality which has not hitherto 
existed in any metal in the pure state, and which adds another 
singularity to this curious metal. — Chemist . 
ON THE DEVELOPMENT OE MUSCULAlt FIBRE IN 
MAMMALIA. 
By Mr. Savory. 
The author’s observations were made chiefly upon foetal 
pigs ; but they have been confirmed by repeated examinations 
of the embryos of many other animals, and of the human 
foetus. 
If a portion of tissue immediately beneath the surface from 
the dorsal region of a foetal pig, from one to two inches in 
length, be examined microscopically, there will be seen. 
