SCIENTIFIC SUMMARY. 
511 
branches form on them, inclining horizontally at an angle, which is the same 
for all in the same solution. In solutions of different densities, the most 
concentrated gives to them the most acute angle. Of this phenomenon the 
following explanation has been advanced : — “ The helicoidal form of certain 
fibres sufficiently indicates that they have been assisted in their development 
by the density of the solution ; they then curve in the line which most 
easily enables them to overcome this resistance ; but there must be another 
cause for those fibres which form an oblique line always equally inclined, for 
they evidently follow this direction on account of the slight resistance thus 
offered to their development. The reason for this appears to exist in a kind 
of invisible cleavage possessed by the solution. If it be admitted that this 
cleavage exists, according to a rhombohedral, as silica belongs to this system, 
all will be explained, for the edges, as well as the faces, of this form are 
inclined horizontally.” — Vide The Artizan, April 1. 
Nitrogen not an Element. — A very cleverly written pamphlet has just been 
written by Mr. Henry Kilgour, to prove that nitrogen is nothing more than 
an allotropic condition of carbonic oxide. Hi^arguments, though exceedingly 
ingenious, and displaymg a careful study of the subject, might, with equal 
force, be applied to prove that nitrogen is an allotropic form of several other 
compounds ; and, for this reason, we think his conclusion is, to say the least 
of it, premature. There is, indeed, evidence of weakness in the case, in the 
circumstance that Mr. Kilgour does not rely upon a philosophic advocacy of 
his views, but adduces the opinion of Professor McCosh, of Belfast, that he 
has worked out his theory with much force of logic. As we do not propose 
to enter here into the discussion, we give beneath the arguments advanced by 
Mr. Kilgour. Granting, he says, that (1st) It is a common occurrence in 
chemistry that the same substance should exist in different states. (2nd). 
When existing in their, different states, the same substance exhibits different 
properties or actions, there are the following facts in proof of his views : — 
{a.) The two substances possess the same fundamental nature or constitution, 
as proven by the sameness (1) of their atomic or combining weights or 
equivalents ; (2) of their combining volume ; and (3) of their specific gravity 
— there being, however, a slight difference between them as to the last. 
{h.) That this difference in specific gravity arises from carbonic oxide 
possessing somewhat more specific heat than is possessed by nitrogen, the 
effect of specific heat being to lessen specific gravity, (c.) That it is this 
difference in the specific heat of carbonic oxide and nitrogen that forms the 
fundamental cause, not only of their difference in specific gravity, but of all 
the other differences in their properties and actions, (cl.) That there are 
numerous other cases in chemistry in which the same cause and the same 
results are exhibited, being classed under the names of Allotrophy and 
Isomerism, (e.) That heat is, or occasions, activity in matter. (/.) That in 
consequence of the greater specific heat of carbonic oxide, it is more active 
or mobile than nitrogen, (y.) That keeping in view the greater activity of 
carbon and its effects, the action of carbonic oxide and nitrogen will be per- 
ceived to be the same. Qi.) More particularly, the fiaming or burning of 
carbonic oxide — nitrogen not fiaming nor burning so readily ; the positive 
poisonousness of carbonic oxide — nitrogen being only negatively poisonous ; 
and their formation of different compounds, — are differences tliat all arise 
