Sept. 23, 1886] 
tions to the latter, he said the problem was whether or not there 
were two great serics of metamorphic rocks unconformable to 
each other, the older referable to the Archean age, the newer 
to the Lower Silurian. Some reference was made to the great 
faults and foldings of these beds, which were stated to range 
generally in N.N.E. and S.S.W. lines. It was considered that 
the granites might belong to at least two periods—the intrusive 
being distinct both in age and structure from the metamorphic 
€ranite and gneiss. Other points noticed were the occurrence 
of numerous basaltic dykes, probably of Tertiary age, traversing 
the gneissose rocks ; and marginal representatives of the Lower 
Carbonife ous period. 
On the Classification of the Carboniferous Limestone Series ; 
Northumbrian Type, by WWugh Miller, F.R.S.E., F.G.S., of 
H.M. Geological Survey.—The object of this paper was to 
show that the classification proposed twenty years back by G. 
Tate of Alnwick is still sufficient, not only for North North- 
umberland, where Tate established it, but also for the south of 
the county. Prof. Lebour has proposed another classification 
on the assumption that Tate’s divisions either do not exist in 
Nature, or do not persist throughout the county. Tate’s classi- 
fication, amplified in some not very important details, and 
adapted to the work of the Geological Survey, is as follows :— 
Feet 
Felltop or Upper Calcareous Division :— 
| From the Millstone Grit to the zone 
of the Great Limestone. Sandstones 
and shales; one or more beds of 
marine limestone, including the Fell- 
top Limestone; some coals... ... 
Calcareous Division:—From the great 
Limestone to the bottom of the Dun cr 
| Redesdale Limestone. Many beds of 
| good marine limestone ; sandstones 
and shales ; coals 
Upper 
Lime- 
stone 
Series 
350-1200 
1300-2500 
 Carbonaceous Division  (Scremerston 
Beds of North Northumberland :— 
From the Dun or Redesdale Limestone 
to Tate's ‘‘ Tuedian Grits.” Strata 
prevalently carbonaceous ; limestones 
chiefly thin, many of them containing 
vegetable matter; coals ... ... ... 
| Tuedian Division :—Upper Tuedian or 
7 | ell Sandstone Group, the ‘* Tueaian 
Grits” cf Tate:—From the Carbon- 
aceous Group to the Cement-Limestones. 
Great belt of massive grits (Tweed- 
¢ mouth, Chillingham, the Simonside, 
| and Harbottle Hills, the Peel, and 
Bewcastle Fells). Shales greenish 
and reddish as well as carbonaceous 
| gray; coals rare, thin, or absent 
Lower Tuedian or Cement-Limestone 
F | Group :—From the tase ef the Grits 
downwards, Cement-stone bands 
passing into limestones (Rothbury, 
Bewcastle) ; coals very rare ; gener- 
| ally some coloration of the shales 
sine SEWER YOINES Eee Aon Seo toe SB 
Basement Conglomerates (Upper Old 
PEC SSAUASUGNE) sO CHL an ateuens. ieee 
__ No’es on the Crystalline Schists of Lreland, by Ch. Callaway, 
D.Sc. M.A., F.G.S.—The author gives a summary of results 
_ obtained by a preliminary survey of the principal areas of Irish 
_ metamorphic rocks in Donegal, Connemara, and the south- 
eastern corner of the county of Wexford. In each of these areas 
the following facts were observed :—(a) A series of hypometa- 
morphic rocks, consisting typically of fine-grained schists, 
altered grits, and quartzites. A clastic structure is more or less 
~ distinct in the three areas, but is least evident in Connemara. 
_ (4) A group of highly crystalline schists, displaying no trace of 
an original sedimentary origin, dipping as if it passed below the 
_ hypometamorphic rocks. At Wexford there are {rue gneisses, 
_In Connemara the rocks are less feldspathic, the chief types 
being quartzose gneiss, quartz-schist, mica-schist, hornblende- 
‘schist, quartzite, and crystalline limestone. This description 
will also apply to Donegal. (c) Granite, underlying (4), and in 
oe remara and Donegal clearly intrusive. The author urges 
Tn 
800-2500 
Lower | 
Lime- 
stone 
Series 
500-1600 
500-1500 
ca 
NATURE 
515 
that this analogy is not due to the metamorphic action of the 
granite ; for—(1) The mineral characters apparent in the schists 
adjacent to the granite are uniformly distributed through the 
lower series from bottom to top. (2) The evidence collected is 
hostile to the view that this lower series ever graduates into the 
upper. It is concluded that the balance of proof is in favour of 
the Archean age of the bulk of the Irish schists. (s) In the 
Wexford district the schists are thrown against Cambrian and 
Ordovician rocks by faults, and do not pass into them in the 
Iecalities alleged by the Irish Survey. (2) In Connemara con- 
glomerates of Llandovery age contain large rounded fragments, 
not only of the older schistose series, but also of its intrusive 
igneous rocks, (3) In the Ulster region the metamorphic area 
is separated from the Ordovician rocks of Pomeroy by a ridge 
of granite and dioiite three miles in breadth. The lithological 
analogies between the Irish schists and the Archean rocks of 
Anglesey and other British metamorphic districts are also of 
weight in the argument. 
SOCIETIES AND ACADEMIES 
EDINBURGH 
Royal Society, July 19.—The sense of taste, by John B. 
Haycraft. Sensation or feeling is a result of the operations of 
the external world upon our sentient bodies. A vibration of 
light, a sonorous wave, a molecule of sugar or of musk stimulates 
the appropriate nerve through the mediation of a little sensitive 
cellule in the eye, the ear. the tongue, or the nose. A motion 
called a verve motion is then set up, passes to the brain, and if 
this organ is in a state of activity we are conscious of a feeling 
or sensation. In the case of sound and light the character of 
the vibration determines the quality of the sensation produced. 
Thus, a certain complex vibration of light produces a sensation 
we call crimson, a certain complex vibration of sound we recog- 
nise as coming from a violin-string. Motion is thus transmitted 
into a nerve motion cr impulse, which gives rise to a sensation. 
Of the thousand qualities of sensation all have a counterpart in 
the thousand variations of motion outside the body, The 
physiologist knows little more about the production of the sense 
of taste than those facts which are the intellectual property of 
every one. The object of the author of the paper of which this 
is a short abstract is to show that taste in its method of produc- 
tion is precisely analogous to sight and hearing. The truth of 
this is indicated by the striking similarity in structure between 
the end-organs of all the special senses, which are all developed 
from primitive ectodermic cells, of much simpler form. Spectro- 
scopic investigation has demonstrated, too, that the sapid and 
odorous molecules vibrate constantly and in a manner character- 
istic of each substance. We have, then, in the case of taste (and 
it is hoped subsequently to demonstrate this in the case of smell 
as well), vibrating matter and a sensitive end-organ, conditions 
analogous with those present in the other senses. If it can be 
shown that substances vibrating in the same manner produce the 
same taste, the analogy will be complete. It has been found by 
Newlands and others that if the elements be arranged in aseries, 
starting with that metal which has the lowest, and passing up 
to that which has the highest, atomic weight, a periodic recur- 
rence of chemical and physical properties is observed. Thus 
lithium, the seccnd in the series, is similar to sodium, the ninth, 
and potassium, the sixteenth, and so on, This is called the 
periodic law. The author finds that there is also a periodicity 
as regards taste production. Thus the chlorides or sulphates of 
a series of similar elements—called a group of elements by 
Mendelejeff—have similar tastes. It is curious, however, that 
the taste changes slightly but uniformly as we pass to the higher 
members of a group. ‘Thus the chlorides of lithium and sodium 
are salt, but as you pass to the higher members of the group 
the taste becomes more saline and very slightly bitter. Now 
Prof, Carnelley has recently discovered that compounds con- 
taining elements of the same group have similar colours, the 
colour changing, however, uniformly—passing to the red end of 
the spectrum—as we reach the higher members of a group. 
Colour is periodic. But this indicates that the elements 
of the same group are vibrating in a similar way. If the lower 
member be yellow from absorption of the blue, the next one 
will have vibrations of nearly the same pitch, being in reality at 
a somewhat slower rate of vibration, and absorbing rays nearer 
the red end. Here, then, is the analogy sought for. A group 
of salts of similar chemical properties have their molecules in a 
