March 31, 1870] 
NATURE 
563 
he will also be appointed to the rank of full surgeon to the hos- 
pital. Two vacancies will therefore occur, that of assistant- 
surgeon to the hospital, and demonstrator of anatomy, 
WE learn from lan Nostrand’s Eclectic Engineering Magazine 
(New York) that the Darien Canal project is reviving. The 
United States steamer /Vifsic, attached to the South Atlantic 
squadron, is under orders to proceed to the Isthmus of Darien to 
make suryeys and explorations, with a view to determine the 
best location for an inter-oceanic canal. A similar survey on 
the Pacific shore of the Isthmus will be made at a future day. 
M. Fayre has recently detected evidences of the glacial period 
in the Caucasus, and M. Ed. Collomb finds traces, in the form 
of moraines and erratic blocks, of its having existed with great 
severity in the central plateau of France. This plateau forms an 
almost circular geological island 300 kilometres in diameter ; its 
altitude increases progressively from north to south, and it is termi- 
nated on the south and west side by a barrier, the highest points 
of which, the Mezenc, the Plomb du Cantal, and the Mont d’Or 
rise to a height of from 1,750 to 1,900 metres (5,700 to 6,200 feet), 
above the level of the sea. 
Tue sense of taste has rarely been submitted to scientific 
examination, or at all events has attracted far less attention than 
its sister senses of sight and hearing, perhaps on account of the 
impossibility of treating it mathematically. That it differs to a 
remarkable extent in different individuals is, however, as every 
culinary artist would acknowledge, a matter of fact ; and it is also 
well known that it is capable of extraordinary cultivation in some 
men, as shown by wine- and tea-tasters obtaining lucrative posts 
from the delicacy of their discrimination. Recently Dr. Keppler 
has published a paper in Piiiger’s “ Archives of Physiology,” in 
which he gives the details of a number of experiments he per- 
formed with a view of determining the limits of gustatory discri- 
mination for sapid substances in various degrees of concentration. 
In these experiments he first made a standard solution, and then 
successively employed weaker or stronger solutions, which were 
tasted with due precautions, sometimes before and sometimes 
after the standard solution, until no perception of flayour was 
distinguished. The substances he selected were common salt, 
quinine, phosphoric acid, and glycerine, all of them, be it ob- 
seryed, destitute of odour, which plays so important a part, 
often overlooked, in our ideas of the flavour of particular objects, 
In one series of experiments the solutions were taken freely into 
the mouth, rolled over all parts of the membrane lining it, and 
then discharged. In a second series the solutions, were more 
carefully applied to the surface of the tongue alone by means of 
a camel’s hair brush. It was found in both cases that when a 
difference of 2°5 per cent. existed between the standard solution 
and the experimental one, the observers were able to form a cor- 
rect judgment on the point that there was a difference in 53 
per cent. of the trials, but when there was a difference between 
the two solutions amounting to Io per cent,, the answers were 
rightly given in 8o per cent. of all the trials. A more correct 
judgment was given when the standard solution was tasted before 
than after the experimental one with common salt and quinine, 
and the acuteness in the perception of a difference was greater 
when the trial solution was stronger than when weaker, but the 
opposite held good for the other substances, 
We learn from the Gardener's Chronicle that the Royal Horti- 
cultural Society has decided to retain a portion of the old Chis- 
wick garden, comprising the ground occupied by the glass-houses, 
and extending sufficiently eastwards and southwards to include 
the large vinery and the fruit-room, 
M. Duciaux has lately been experimenting on the effect 
ef certain gases in retarding the incubation of silkworms’ 
eggs. He has also been trying the effect of cold upon 
the same organisms, and finds that instead of retarding the period 
of inenbation, it accelerated it: in fact, that eggs laid in autumn 
and left to themselves would only incubate in spring ; but if sub- 
jected to the action of a freezing mixture for forty days, they 
would hatch into larvee immediately afterwards, on being submitted 
to the action of a gentle heat. If these experiments are confirmed, 
M. Duelaux will have undoubtedly discovered an entirely new 
principle in physiology: that cold has a vivifying influence. 
Hitherto physiologists have always believed that its action was 
diametrically opposite. 
THE journal of the Proceedings of the Asiatic Society of 
Bengal for January has an interesting article by Dr. F. Skoliczka 
on the Kjékenméddings of the Andaman Islands. 
THE Journal of the Scottish Meteoralogical Society has some in- 
teresting papers on the cold of last summer in Ireland, and 
upon the thunderstorms of Scotland, The part also contains a 
report on the Meteorology of Scotland and a minute of the 
meeting of the Council, . 
THE American Gas Light Journal reports that at a recent 
meeting of the Lyceum of Natural History. of New York, Mr. 
Loew stated that ozone is produced copiously by blowing a 
strong current of air into the flame of a Bunsen’s burner. He 
also communicated that he had observed the decomposition of 
sulphurous acid with production of sulphuric acid and deposition 
of sulphur, when an aqueous solution of the gas was exposed for 
two months to sunlight, 
Tuer hardness of metals may now be ascertained by the aid 
of an instrument invented by a French engineer. It consists 
of a drill turned by a machine of a certain and uniform strength. 
The instrument indicates the number of revolutions made by the 
drill. From this, compared with the length of the bore-hole 
produced, the hardness of the metal is estimated. It is said 
that a great proportion of the rails now employed in France are 
tested by this instrument. 
ON THE TEMPERATURE AND ANIMAL LIFE 
OF THE DEEP SEAS 
Ill. 
AN enormous addition has been made to the list of British 
Echinodermata by the discovery in our own seas of a number 
of species which had been previously known only as Norwegian 
or Arctic ; and these often occurred in extraordinary abundance. 
One of the most interesting of these was the large and beautiful 
feather-star, the Azfedon (Comatula) Eschrichtiz, hitherto known 
only as inhabiting the shores of Greenland and Iceland, but now 
found oyer all parts of our cold area, On the other hand, the 
influence of temperature was marked not only by the absence of 
many of the characteristically southern types of this group, but 
by the dwarfing of others to such an extent that the dwarfed 
specimens might be regarded as specifically distinct, if it were 
not for their precise conformity in structure to those of the ordi- 
nary type. Thus the So/aster papposa was reduced from a 
diameter of six inches to two, and had neyer more than ten rays, 
instead of from twelve to fifteen ; and Asterocanthion violaceus 
and Cribella ocylata were reduced in like proportion. But, in 
addition, seyeral echinoderms haye been obtained which are 
altogether new to science, most of them of very considerable 
interest. The discoyery, at the depth of 2,435 fathoms, of a 
living crinoid of the Apiocrinite type, closely allied to the little 
rhizocrinus (the discoyery of which by the Norwegian naturalists 
was the starting-point of our own deep-sea explorations), but 
generically differing from it, cannot but be accounted a phe- 
nomenon of the greatest interest alike to the zoologist and the 
palontologist. Another remarkable representative of a type 
supposed to have become extinct, occurred at depths of 440 and 
550 fathoms in the warm area; being a large echinidan of 
the diadema kind, the ‘‘test” of which is composed of plates 
separated from one another by membrane, instead of being 
connected by suture, so as to resemble an armour of flexible 
ehain-mail, instead of the inflexible cuirass with which the 
* A Lecture delivered at the Royal Institution (continued from p. 540). 
