- Oct. 13, 1870 | 
: 
NATURE 
487 
at 3 French feet being 1°7, while at 24 French feet it is reduced 
to 1°. The soil of which the Observatory Hill is composed, and 
in which the thermometers are sunk, is dry gravel, and the 
unusual circumstance of decrease of temperature downward 
observed in the comparison of the 3 feet and 24 feet thermometers, 
seems to indicate that the surface of the hill is warmer than 
the surrounding land. 
4 
j 
7 
In the present state of our knowledge, then, it appears that 
when the temperature of the earth has been observed at a 
depth of some hundreds of feet in any locality in Great Britain, 
and has not been accurately determined at a less depth, some 
knowledge of the rate of increase downwards may be obtained, 
by assuming provisionally that the mean temperature of the 
surface is about a degree higher than the mean temperature of 
the air, supposing the latter to be known. 
It is to be wished that the Meteorological Society would, 
_ from the ample materials in their possession, publish a map 
of annual isothermals for Great Britain ; and the objects of this 
committee would be greatly furthered by an extensive series of 
soil temperature observations at the depth of about 3 feet. 
The committee are anxious to carry into effect Mr. Hull’s 
proposal (quoted in their last Report) to bore down from the 
bottom of a deep mine ; and as Rosebridge Colliery appears to 
be an eminently suitable locality for such an operation, the 
Secretary has consulted Mr. Bryham respecting its practicability 
and probable cost. Mr. Bryham’s reply is that there would be 
no difficulty in carrying out the proposal at Rosebridge, that to 
make preparations and bore 300 feet would, on a rough estimate, 
cost £150, and that the second 300 feet would probably cost 
about the same sum. 
The committee would earnestly appeal to the liberality of the 
Association to enable them to put this design in execution, and 
they would remark that the sooner it is carried out, the more 
valuable the results obtained will be, as the mine has been but 
recently opened to its present depth, and the influence of atmo- 
spheric temperature will every year become more sensible in the 
strata below. 
SCIENTIFIC SERIALS 
In the Annalen der Chemie und Pharmacie for May 1870, we 
find several important papers, of which the following are 
abstracts :—‘‘ Investigations on some derivatives of cinnamic 
acid, by Carl Glaser.” In this lengthy and most interesting 
paper is described the Phenylpropiolic acid CyH,O,, a new acid 
which differs from cinnamic acid by containing H, less. It is 
obtained either by the action of sodium and CO, on B brom- 
styrol, or by the action of alcoholic potash on a bromcinnamic 
acid. On heating with water to 120°, it splits up into CO, and 
acetenylbenzol C,H C,H,, which latter can also be obtained by 
the abstraction of 2 HBr from dibromstyrol. Silver, copper, 
and sodium derivatives of this remarkable hydrocarbon are de- 
scribed, from the latter of which, by the action of CO,, the author 
succeeded in regenerating phenylpropiolic acid. The paper 
concludes with an account of some Cl and Br derivatives of 
styrol.—‘‘ On mercuryditolyl,” by E. Dreher and R. Otto. A 
white crystalline compound obtained by the action of Na, Hg on 
bromtoluol, The authors did not succeed in preparing the cor- 
responding mercury compound from the isomeric brombenzyl.— 
Note on the behaviour of dibenzyl at high temperatures, by the | 
same authors. This compound is split up according to the 
, CHG H.= TG { CHC,H; 
equation 2 CH,C,H, = 2 CyHCHy + (GE C,H; 
Toluylen 
‘Note on the conversion of Thiophenol (Phenylic sulphydrate) 
into Phenylic disulphide,” by the same authors. This is effected 
by distilling the mercury compound of the former, when it splits 
up into mercury and the bisulphide, which is probably due to 
the decomposition taking place at a temperature at which the 
affinity of Hg for S does not yet come into play, since the 
homologous toluol and benzyl compounds, which require a much 
higher temperature, give mercuric sulphide and a monosulphide, — 
On two isomeric pentachlorbenzols and bichlorbenzols-chlo- 
ride,” by R. Otto. A short description of the mode of pre- 
paration and properties of the abovecompounds. The existence 
of two pentachlarbenzols, which now seems to be placed beyond 
all doubt, is of great interest, as it is one of the yery few facts 
irreconcileable with MKeékule’s benzol theory, which does not 
admit of the existence of more than one.—‘‘ On sulphotoluid,” 
by R. Otto and Gruber. Obtained by the action of sulphuric 
anhydride on toluol.—‘*On aceto-mercury monomethyl and 
aceto-mercury monethyl,” by R. Otto. These two compounds 
are prepared by the action of acetic acid on mercuric methide 
and ethide respectively, 
CH, } (CHa ys CHE 
CH; § | COOH = G,H,0, 
Hg + Hg + CH, 
—‘‘On the preparation of organic sulphur compounds by means ot 
sodic hyposulphite,” by the same author, Alcohol heated with 
a concentrated solution gives mercaptan; ethylic iodide mer- 
captan and ethylic sulphide; chlorbenzyl gives benzylic mer- 
captan and sulphide.—‘‘On diamidonitro phenylic acid, a new 
derivative of picric acid,” by Peter Griess. This acid is pre- 
pared by the reduction of picric acid with ammonic sulphide.—- 
**On azobenzol sulphuric acid,” by P. Griess. A product of 
the action of hot fuming sulphuric acid on azobenzol. By fusion 
with potash, phenoldiazobenzol C,,H,,N.O is obtained, which 
on treatment with ammonic sulphide, is conyerted into oxyben- 
zidin_ C,,H,,N,O.—‘‘ On ozone and antozone,” by C. Engler 
and O Nasse. In this lengthy paper are described a long series 
of experiments, all of which seem to prove conclusively the non- 
existence of the third modification of oxygen, called by Schonbein 
and others antozone, and which the authors prove to be hydric 
peroxide formed by the oxidation of water, which was present 
in all those cases where the so-called antozone has been observed 
by ozone.—‘‘ On the constitution of arbutin,” by Hugo Schiff. 
The author considers arbutin to be derived from one atom glycose 
+ one atom hydroquinone -H,O, and describes a number of 
acetyl and benzoyl derivatives in support of his views. —“On 
the action of hypochlorous acid on allylic chloride,” by H. v 
Geyerfell. The author has obtained the compound C,H,OCl, 
by direct addition of the elements of hypochlorous acid to allylic 
chloride. This on reduction with sodium amalgam yields a 
liquid, probably allylic alcohol. (?)—‘‘ On a new method for the 
estimation of grape sugar,” by Karl Knapp. This method is 
based on the fact that an alkaline solution of mercuric cyanide 
is entirely reduced to metallic mercury by grape sugar. By 
direct experiment it was found that on boiling, 409 mer. 
Hg(CN), are reduced by 100 mgr, sugar. The solution is pre- 
pared by dissolving 10 grm. pure dry Hg(CN), in water, adding 
100 cc. of a sodic hydrate solution of 1145 sp. gr., and diluting 
to 1,000 cc. Pure grape sugar is prepared by recrystallising 
the commercial dried at 100°, from absolute alcohol. The ex: 
periment is performed by heating 40 ce. of the mercury solution— 
this amount corresponds to 100 mgr. sugar—to boiling in a 
porcelain dish, and then adding sugar solution to complete 
precipitation of the mercury, the end of the reaction being ascer- 
tained by placing a drop of the liquid on to a piece of the finest 
Swedish filter paper, covering a small beaker containing some 
very strong ammonic sulphide; a brownspot is observed so 
long as mercury remains in_solution. The advantages of this 
method over Fehling’s are, that being equally accurate, the test 
solution is exceedingly easy to prepare and perfectly stable, a 
shorter time is required for the estimation, and that the foreign 
bodies which mask the pure colour of the cuprous oxide are 
without influence on the reduction of the mercuric cyanide.— 
“On some isopropyl compounds,” by R. D. Silva. In this 
notice are described isopropylic succinate, benzoate, nitrite, and 
nitrate, all prepared by the action of isopropylic iodide on the 
respective silver salts of the acids, 
THE Journal of Botany, British and Foreign, for September 
contains a paper by Dr. H. Trimen on Early Icelandic Botany, 
including an account of Rotboll’s observations on the new or 
little-known but rare plants found in Iceland and Greenland, 
which appears to have been overlooked by Professor Babington 
in his “‘ Revision of the Flora of Iceland.” It was published in 
1770, and adds a few species to the number stated by Professor 
Babington to be indigenous to Iceland. We have also one of 
Mr. J. G. Baker's careful and useful contributions to British 
systematic botany, an account of the British dactyloid saxifrages, 
which he states to form a complete series of varieties from S. 
caspitosa to S. hy~noides, without any clearly marked gap at 
any point between the extremes; and the line of progression 
substantially straight, very little if at all complicated, as in the 
case of Awbus, by cross-relationships. The order of sequence is 
as follows; 1. S. casfitosa, 2, S, Sternbergit, 3. S. decipiens, 
