- 
54 REPORT—1850. 
At the Chemical Section of the British Association, held at Oxford in 1847, Dr. 
Faraday exhibited some specimens of the diamond coke which had been forwarded 
to him by M. Jacquelin; and subsequently, on the 16th of June 1848, he publicly 
showed the experiments in London in the theatre of the Royal Institution. 
On repeating the experiments a short time since before a few private friends, I 
obtained a product so totally different from that of M. Jacquelin, that I am induced to 
bring the subject before this Section, in the anticipation that it may tend to elicit 
some observations on a phenomenon which at the time attracted the attention of many 
electricians. 
The apparatus I used in this experiment consisted of forty series of the usual size 
of Groye’s nitric acid battery ; the terminals were made from two pieces of well- 
burnt boxwood-charcoal, that attached to the positive or platinum end of the battery, 
being formed in the shape of a small cup or crucible, in which the diamond was 
placed ; to the negative or zine end of the battery a piece of the same charcoal (but 
pointed) was attached, 
The experiment was then made in the same form as described by M. Jacquelin, by 
first making contact with the two charcoal terminals, then bringing the flame in 
such a position as to cause it to surround the diamond; in less than one minute the 
diamond as well as the electrode became in a state of intense ignition ; the diamond 
gradually increased in size, rolling about in the heated crucible, when it suddenly 
expanded, forcing itself upwards on the negative terminal, at which moment I sepa- 
rated the electrodes. 
The diamond, which was in a state of intense ignition, remained attached to the 
negative terminal. When cool, it exhibited the same state as it now presents; it was 
expanded to eight or ten times its original bulk. Instead of becoming a black car- 
bonaceous substance and a good conductor, it has a vitreous, white, opake appearance, 
and remains a non-conductor. It has also a deep circular cavity on that portion 
which was opposite and nearest to the positive electrode, that part which was in con-~ 
tact with the negative electrode being clearly discernible by a small portion of the 
boxwood-charcoal remaining attached to it. The centre of the cavity appears to be 
still brilliant, as if that portion of the diamond had not been in a complete state of 
fusion, 
In one or two other experiments the diamond disintegrated, the fragments remaining 
in a carbonaceous state; since which I have not had the opportunity of repeating the 
experiment, 
Observations on the Growth of Plants in Abnormal Atmospheres, 
By Dr. J. H. Guapstone and Mr. G. GLADSTONE. 
Though oxygen is the most important constituent of the atmosphere, so far as ani- 
mal life is concerned, it is upon the carbonic acid, ammonia and aqueous vapour that 
the vegetable world is mainly dependent. 
The question arises, Do the oxygen and nitrogen of the air play no important part 
in the process of vegetation? The following preliminary experiments, with a view 
to the solution of this and similar inquiries, were detailed by the authors :— 
A pansy lived for the length of twenty-four days in an atmosphere of hydrogen 
containing 5 per cent. of carbonic acid; one similarly placed in an atmosphere of 
common air remained healthy for a longer period. 
Five onions, just commencing to sprout, were severally placed in carbonic acid, 
earbonic oxide, coal-gas, air containing 8 per cent. of light earburetted hydrogen, and 
ordinary atmospheric air. The germination of the two first was entirely stopped, 
while the hydrocarbons appeared considerably to accelerate the growth of the vege- 
table. The plants in each instance lost weight. 
A pansy in flower, a young stock and a grass plant were placed in pure nitrogen 
gas. The two former soon died, but the grass was left growing a month after the 
commencement of the experiment. 
Another pansy was placed in a mixture of oxygen and hydrogen gases in the pro- 
portion requisite to form water. In order to imitate the balance that obtains in 
nature between animal and vegetable life, some flies were introduced, along with 
some sugar, to serve as their food, The experiment was commenced a fortnight 
since; and the plant, when last observed, was in good condition. Owing to the low 
