1866. | Annual Retrospect. 137 
at present in use. There exists much difference of opinion 
upon this question. The discussions which have taken place 
have not produced anything approaching to uniformity in the 
notation of even modern chemists; while those of the older schools 
see nothing but confusion in the systems proposed—adopted— 
modified—and abandoned in succession. Itisto be hoped that from 
amongst the ranks of our young chemists, many of whom exhibit 
great originality of thought and considerable mental power, some 
oe will seriously undertake the task of reducing the overburthened 
system which is now adopted to a state of simplicity and order. 
Investigations have been steadily carried forward in connection 
with the new and rare metals with which spectrum analysis made 
us acquainted ; and new sources from which these metals can be 
obtained, have been discovered. 
Mr. H. C. Sorby, with his usual ingenuity, has applied spec- 
trum analysis to the Microscope, and has employed it in making 
some important investigations on the detection of blood-stains. 
Considerable advances have been made in determining the positions, 
numbers, and conditions of the dark lines in the solar spectrum and 
their agreement with the lines produced by known substances. 
Much interest was excited by a published statement that anto- 
zone had been isolated by Schénbein, and the compound condition 
of oxygen determined. This has not been done; indeed the existence 
of such a body as antozone is somewhat problematical. It is, 
however, satisfactory to see that the evidence on the peculiarities 
and properties of ozone are accumulating, and proving this 
allotropic state of oxygen to be of high importance in the economy 
of nature. 
Inorganic chemistry has discovered several new minerals, and 
many inquiries of much practical importance have been carried out. 
Weil, by his simple process of coating one metal with another, 
without the aid of a voltaic battery, has introduced a process which 
must greatly extend the advantages of electro-metallurgy. 
Deville and Troost, by their discovery of the permeability of 
certain dense metals at elevated temperatures to gases, have opened 
a most curious inquiry on the boundary line between physics and 
chemistry. Deville’s experiments on the phenomena of dissociation, 
or the partial decomposition of compound gases under the influence 
