Fan. 6, 1870] 
INCA IMGT SIE 
269 
A HAppy idea, very ingeniously carried out, is the Pharma- 
ceutical or Medico-Botanical Map of the World, produced by 
Mr. George Barber, of Liverpool. Ina very clearly printed and 
carefully-coloured map we are shown at a glance the Aaditats of 
all the medicinal plants and drugs in general use, as well as the 
mean annual temperature of the countries whence they are 
obtained, The map is published by Simpkin, Marshall, and Co. 
M. E. LirppMANN has communicated to the dunales Indus- 
trielles an account of the operations for sinking the Artesian 
Well at La Chapelle. The engineers employed by the authorities 
of the city of Paris to execute this great work, are MM. 
Degosée, Laurent, and Co. When completed, this well will 
supply water to one of the most populous quarters of Paris. It 
is intended that the well shall not only strike the water-bearing 
stratum—at a depth of about 2,000 feet—into which the great 
well at Passy penetrates, but shall extend through the stratum to 
a total depth of 2,950 feet. In this way, other water-bearing 
layers will be intersected. The work was at first commenced 
by the ordinary method of sinking a masonry shaft 2 metres 
(6ft. 3fin.) in diameter to a depth of 445 feet through the 
tertiary strata which lie above the ‘chalk. Many difficulties 
presented themselves, chiefly due to the looseness of the’ earth 
through which the excavation penetrated, and to the insufficient 
pumping-power. After two years of persistent_labour, it was 
decided to try another system. At this period the shaft had 
reached a depth of 113 feet ; new boring machinery driven by | 
steam power was now set up, and until the present time the 
work has proceeded most satisfactorily. 
ASTRONOMY 
Prizes for the Discovery of Comets 
Tue following circular has been issued by the Imperial Aca- 
demy of Sciences at Vienna :—- 
For several years past there have been remarkably few dis- 
coveries of new comets. The cause of this fact, which seems 
inconsistent with that of the wider distribution of telescopes 
suitable for such discoveries, may be due to the special attention 
that has been given to the small planets. It is, however, much 
to be regretted that there has been such slight increase in our 
knowledge of the comets, in view of the recently established 
connection between the shooting stars and the comets. It is 
exceedingly desirable that we should know more than two or 
three hundred out of the many thousands of comets which 
undoubtedly belong to our system, especially as most of those 
which we know move in parabolic orbits. Were our knowledge 
of comets more complete we should surely know of more meteor 
streams and comets belonging one to the other. Mindful of Herr 
Schumacher’s words “it is natural that astronomers intrusted with 
the administration of a well furnished observatory should have no 
time left for sweeping the sky so minutely and so perseyeringly 
as is necessary for discovering these faint bodies, whilst, on the 
contrary, it seems certain that to the many amateur astronomers 
who have less extensive means of observation hardly any more 
useful kind of activity could be recommended,” the Imperial 
Academy of Sciences at Vienna is induced to propose for the 
discovery of comets_during the three years from May 31,1869, 
to May 31, 1872 eight prizes~ annually, consisting, as the 
receiver may choose, of a gold medal, or of twenty Austrian 
ducats representing its value in money. 
The award of these prizes will be subject to the following regu- 
lations :— 
1. The prize will be given only for the first eight comets dis- 
covered in each of the three years named, and only for such 
comets as are telescopic at time of discovery, that is, invisible to 
the naked eye. The comet must not haye been before seen by 
another observer, and must be one whose appearance could not 
be predicted with certainty. 
2. The discovery must be communicated immediately and 
without waiting for further observations, to the Imperial Aca- 
demy of Sciences, by telegraph if practicable ; and otherwise by 
the earliest post. The Academy undertakes to transmit the news 
immediately to other observatories. 
3. The time and place of discovery with the plan and course 
of the comet must be given as exactly as possible with the first 
notice. This first notice is to be supplemented by such later 
observations as may be made. 
4. If the discovery should be confirmed by other observers. 
the prize wi!l not be awarded unless the observations of the dis- 
coverer suffice for the determination of the orbit. 
5. The prizes will be awarded in the general meeting of the 
Academy held at the end of May of each year. In case the first 
notice of a discovery arrives between the 1st of January and the 
end of May, the final award of the prize will be deferred till the 
general meeting in May in the following year. 
6. Application for the prize must be made to the Academy 
within five months from the time of the arrival of the first notice. 
Later applications will not be considered. 
7. The Imperial Academy will procure the decision of the 
permanent astronomers of the Observatory at Vienna as to the 
fulfilment of the conditions in Nos. 1, 3, and 4. 
The New Planet (109) 
In the Astronomische Nachrichten, 1779-80, there is a long 
and important article on Piazzi’s observations by M. Argelander ; 
also the approximate place of this planet, discovered by Prof. 
Peters of Clinton, New York. 
The following elements of the Planet are by Prof. Peters, 
and are considered by him to be nearly accurate. We print in a 
parallel column the elements for the same planet as furnished 
by Prof. Axel Moller, of Lund. The latter are calculated from 
observations taken at Clinton on Oct. 13th, Leipzig Noy. 8th, 
and Lund Noy. 26th, 1869 :— 
Epoch 1869, Oct. 0’o Berlin mean time. 
My = 337, 1 3ra50 350° 53’ 28°6" 
ee oe ater 
OS ao ging) ae. BY OE 
p= EES SES | 8° 3 578 
o = 17 25 14°13 \ 17 27' 510" 
hb = $09"580 800476" 
log a = 0°4278314. 
CHEMISTRY 
Transformation of Chlorinated into Ilodated Compounds 
Ap. LIEBEN has made important experiments on this kind of 
transformation. Ethyl chloride, mixed in a sealed tube with three 
or four times its weight of strong hydriodic acid, sp. gr. 1°9, and 
heated for five hours to 130°, is almost wholly converted into 
ethyl iodide, according to the equation— 
C,H;€l+ HI=C,H,I + HCl. 
In like manner ethylated ethyl chloride (butyl chloride), and 
amyl chloride are converted by strong hydriodic acid into the 
corresponding iodides, without formation of secondary products. 
C,H,(C,H;)Cl ) 
Cc 
ails 
Ethyl-chlorinated ethyl oxide O is converted, 
by an excess of strong hydriodic acid, chiefly into ethyl iodide, 
and ethylated ethyl iodide (butyl iodide) ; but there are also 
some secondary products formed, viz. butyl chloride, alcohols, 
and a substance having a carbonaceous aspect, the quantity of 
these secondary products increasing as the hydriodic acid is less 
concentrated and present in smaller quantity. 
To determine whether the action of hydriodic acid is a simple 
double decomposition or a case of the action of masses, the 
conyerse reaction was tried by heating ethyl iodide with a con- 
siderable excess of hydrochloric acid in a sealed tube to 130°. 
A small quantity of ethyl-chloride was thereby obtained, together 
with hydriodic acid and free iodine, showing that the inverse of 
the first-described reaction does really take place; but the quantity 
of ethyl chloride, which it yields, is very small, even when the 
action is continued for 50 hours. The result of the two supple- 
mentary experiments, namely, the decomposition of ethyl chloride 
by hydrogen iodide, and of ethyl iodide by hydrogen chloride, 
may be represented, though somewhat crudely, in the following 
manner— 
(Affinity of H for I) + (Affinity of C,H, for Cl) 
< (Affinity of H for Cl) + (Affinity of C,H, for 1). 
The decomposition of ethyl chloride, and its homologues by the 
action of hydriodic acid, is analogous to the decomposition of 
silver iodide by the same reagent. 
As an example of the action of hydriodic acid on organic 
chlorides of other series, chloroform CHCl, was “introduced, 
together with 11 times its weight of hydriodic acid of sp. gr. 1°9, 
