Vol. XXV. No. 6.] 
POPULAE SCIEIvrCE E"EWS. 
81 
form. Aniline red or magenta (a derivative of 
rosaniline) gives a very well defined figure. (See 
Fig. 3.) A solution of fluoresceine, as it is com- 
monly termed, gives a truly splendid submersion 
figure. In each of these cases the phenomena of 
fluorescence which these substances exhibit — t. e., 
a color which may be described as an apple-green, 
glow — greatly heightens the effect of the experi- 
ments. But here it is necessary to say that only 
on a bright, sunny day can the latter effects be 
best seen, although, of course, the lime light, the 
electric light, or that obtained by burning a piece 
of magnesium wire are for this purpose good sub- 
stitutes for daylight. 
STecessarily, for each experiment with color 
matters, a fresh column of water would be re- 
quired, whether varied by the presence of a chem- 
ical salt in solution or otherwise. If, instead of 
coloring bodies, liquids are used for these experi- 
ments, — such as the essential oils (i. e., lavender. 
ilove, coriander, bergamot, etc.),— and in place of 
k water column any of the following fluids : ben- 
ol, naphtha, methylated spirit, common kerosene 
etc., a great variety of submersion figures 
nay be obtained. Some of these are of extraordi- 
»ry beauty; moreover, it is a beauty strictly 
aracteristic of the substances so used. The 
Bost remarkable of any is one which, when fully 
eveloped, displays an architectural symmetry 
aite surprising. A drop of common fusel oil (or 
amyl alcohol, as chemists term it) in its descent 
through a column of kerosene oil produces this 
eftect. Moreover, the duration of the figure is 
considerable, notwithstanding its delicate and 
gauze-like texture. (See Fig. 4, a, 6, c, d.) The 
common and not refined kerosene oil must be used 
to ensure success with this experiment. This 
class of figures varies greatly with considerable 
changes of temperature, and not only with sub- 
stances which require to be melted, but with oils 
which are fluid at ordinary temperatures. 
A little sketch of the history of the subject is 
here necessary. As the result of his researches. 
Prof. W. B. Rogers contributed a paper to the 
American Journal of Science, in 1858, entitled, 
"On the Formation of Rotation Rings by Air and 
Liquids under Conditions of Discharge." About 
four years later Professor Tomlinson, in England, 
made an independent series of observations on 
these fluid rolling rings and their allied phenom- 
ena. In the case of the liquid ring he concluded 
that the forces are (1) difl'usion, which forms the 
ring, and (2) gravity, which causes it to sink. 
The resistance is due to friction retarding (1) the 
descent of the ring and (2) its dUSision. In the 
case of a ring of smoke or other vapor tlie forces 
are precisely the same, only gravity causes it to 
ascend and friction retards the ascent. Most 
attention has been given to the subject by Tom- 
linson and Deacon. While the former regards 
the fully developed figures — which he terms 
"submergence cohesion figures"— as due to dif- 
fusion, the latter is of the same opinion as Pro- 
fessor Roberts, viz., that they are true cases* of 
vortex motion, not from diftusion, but from the 
ordinary motion which follows the Impact of two 
bodies. By way of illustration he refers to the 
cold metal ring formed round the top of a smith's 
chisel by long continued hammering. Moreover, 
he thinks, though it may modify and thus in one 
sense be said to create these phenomena, yet diffu- 
sion is the cause of their destruction. 
Lastly, as to the utility of submersion figures. 
In this intensely practical age, when persons meet 
with scientific novelties they are apt to ask, "Of 
what use are these?" In view of the fact that 
each'liquid or set of liquids above named, and 
many more which have not been mentioned, fur- 
nishes its own characteristic figure, Professor 
Tomlinson considers they are capable of serving 
for purposes of " rough qualitative analysis." 
Those who care to pursue the subject system- 
atically and exhaustively — if we may apply the 
latter term to any branch of scientific investiga- 
tion — are referred to Tomlinson's contribution to 
the Philosophical Magazine for June, 1864, entitled, 
" On a New Variety of Cohesion Figures." Not 
less full of interest and value are the numerous 
papers on kindred subjects published by this dis- 
tinguished scientist, whose years are now four- 
score, the friend of Faraday and other world- 
renowned students of Nature. 
<♦> 
SPECTRUM OF THE SUN AND ELEMENTS. 
The Johns Hopkins University Circular, No. 85, 
issued in February, contains Professor Rowland's 
report of progress in spectrum work. The spectra 
of all known elements, with the exception of a 
few gaseous ones, or those too rare to be yet ob- 
tained, have been photographed in connection 
with the solar spectrum, from the extreme ultra- 
violet down to the D line, and eye observations 
have been made on many to the limit of the solar 
spectrum. A table of standard wave lengths of 
the impurities in the carbon poles extending to 
wave length 2,000 has been constructed to meas- 
ure wave lengths beyond the limits of the solar 
spectrum. In addition to this, maps of the spec- 
tra of some of the elements have been drawn up 
on a large scale, ready for publication, and the 
greater part of the lines in the map of the solar 
spectrum have been identified. The following 
rough table of the solar elements has been con- 
structed entirely according to Professor Row- 
land's own observations, although, of course, 
most of them have been given by others : 
ELEMENTS IN THE SON, ARRANGED ACCORDING TO 
INTENSITY AND THE NUMBER OF LINKS IN THE 
SOLAR SPECTRUM. 
According to intensity. 
According to number. 
Calcium 
Zirconium 
Iron (2,000 or 
Palladium 
Iron 
Molybdenum 
more) 
Magnesium (20 
Hydrogen 
Lantlianum 
Nickel 
or more) 
Sodium 
Niol)ium 
Titanium 
Sodium (11) 
Nickel 
Palladium 
Manganese 
Silicon 
Magnesium 
Neodymlum 
Chromium 
Sti-ontium 
Cobalt 
Copper 
Cobalt 
Barium 
Silicon 
Zinc 
Carbon (200 
Aluminium (4) 
Aluminium 
Cadmium 
or more) 
Cadmium 
Titanium 
Cerium 
Vanadium 
Rhodium 
Chromium 
Glucinum 
Zirconium 
Erbium 
Manganese 
Germanium 
Cerium 
Zinc 
Strontium 
Rhodium 
Calcium (75 
Copper (2) 
Vanadium 
Silver 
or more) 
Silver (2) 
Barium 
Tin 
Scandium 
Glucinum (2) 
Carbon 
Lead 
Neodymlum 
Germanium 
Scandium 
Erbium 
Lanthanum 
Tin 
Yttrium 
Potassium 
Yttrium 
Lead (1) 
Niobium 
Potassium (1) 
Molybdenum 
DOUBTFUL ELEMENTS. 
Iridium, osmium, platinum, ruthenium, tanta- 
lum, thorium, tungsten, uranium. 
NOT IN SOLAR SPECTRUM. 
Antimony, arsenic, bismuth, boron, nitrogen, 
Cffisium, gold, indium, mercury, phosphorus, ru- 
bidium, selenium, sulphur, thallium, praseody- 
mium. 
With respect to these tables. Professor Rowland 
adds : " The substancjis under the head of ' Not 
in Solar Spectrum ' are often placed there because 
the elements have few strong lines or none at all 
in the limit of the solar spectrum when the arc 
spectrum, which I have used, is employed. Thus, 
boron has only two strong lines at 2,497. Again, 
the lines of bismuth are all compound, and so too 
diffuse to appear in the solar spectrum. Indeedj 
