of Edinburgh, Session 1884-85. 
175 
sphere of the far larger, and still growing, historic city of Edinburgh ; 
viz., the excessive quantity of coal-smoke now vitiating its atmosphere, 
and almost prohibiting any of the nicer observations of Practical 
and Physical Astronomy. 
The three several Winchester spectra so taken, have been kept 
equally separate during all the following stages of computation, and 
even up to their very insertions into the final collective plate-forms. 
In the meantime the two eclectic spectra already mentioned, had been 
introduced in pen and ink on those plates for the Author, by Mr 
Thomas Heath, Pirst Assistant Astronomer, E. Ob. Edin . ; ensuring 
thus not only better draughtsmanship, but a still further degree of 
independence whenever a questionable case, whether of agreement 
or disagreement, should occur, between any of the 6, or 7,000 lines 
5 times repeated. 
Three, however, only of the five, sets, viz., the Author’s three, 
appertain to the year 1884; — a period of well marked anomaly in 
the higher regions of the earth’s atmosphere, as shown by the broad 
halo apparently around, or rather in front of, the Sun during the 
whole of that time, — a condition which is considered in the course 
of the paper. 
2. On Knots. Part III. (Amphicheirals). By Prof. Tait. 
3. On the Chemistry of Japanese Lacquer. By Hikorokuro 
Yoshida, Chemist to the Imperial Geological Survey 
of Japan. Communicated by Hugh Eobert Mill, B.Sc. 
The lacquer tree ( Rhus vernicifera) is indigenous to Japan ; it 
supplies a valuable timber, and its fruit yields vegetable wax, but it 
is chiefly cultivated on account of its juice — lacquer ( Urushi ) — which 
forms the basis of the famous Japanese varnishes. The juice is. 
obtained by making incisions in the tree, and it is made into a 
varnish by simply stirring in the sun in order to drive off an excess 
of moisture. Different colours may be imparted to the varnish by 
the addition of various metals, oxides, and sulphides ; and after it 
has been applied to an object it must be hardened by exposure to a 
moist atmosphere at a moderately high temperature.* 
* For particulars as to the preparation and use of lacquer, see the essay in 
Forestry and Forest Products, Edinburgh, 1885, p. 515, of the chemical part of 
which this paper is an abstract. 
