53> 
NATURE 
under the guidance of Bunsen and Kirchhoff. His first 
paper, “ On the Preparation of the Metals of the Alkalies 
and Alkaline Earths by Electrolysis,” appeared in the 
Annatlen der Chemie und Pharmacie for March 1855, and 
was devoted to a description of the preparation and pro- 
perties of the metals calcium and strontium, then 
isolated for the first time. Calcium he found to be a 
metal of the colour and glance of bell metal, exceedingly 
ductile and malleable ; using water as the exciting fluid, 
he found it to be electropositive to magnesium, and electro- 
negative to sodium and potassium, which at once explained 
why it could not be obtained from its chloride by the 
action of sodium or potassium at high temperatures. 
Next in order is a paper of his in Poggendorf’s Anmalen 
for 1857, communicated by Kirchhoff, in whose laboratory 
the results were worked out, entitled, “ On the Electric 
Conductivity of Potassium, Sodium, Lithium, Magnesium, 
Calcium, and Strontium.” Following this, appear in 
Poggendorf’s Axmadlen for 1858 two communications from 
him “On the Electric Conductivity of Metals,’ and “ On 
the Thermo-electric Series.” On his return to London he 
worked some time at the Royal College of Chemistry 
under Hofmann, and published a paper “On the Action 
of Nitrous Acid on Aniline.” Hunt had described phenol, 
free nitrogen and water as the products of this reaction, 
but he found that an intermediate reaction took place, by 
which ammonia was formed ; extending his experiments 
to ethyl and diethylaniline, he obtained ethylamine and 
diethylamine. It was this reaction which first led him to 
the study of narcotine, which afterwards in his hands 
yielded such splendid results. After working diligently 
several years in a laboratory which he fitted up for him- 
elf in Torrington Square, he was appointed Professor of 
Chemistry to St. Mary’s Hospital in 1862. It was about 
this period that his most important researches were carried 
out in conjunction with Dr. Vogt, Von Bose, Holzmann, 
&c., and published in a series of papers in the Philo- 
sophical Transactions of the Royal Society, to which he 
was admitted a Fellow in 1861. Some of the most im- 
portant of these papers are those ‘On the Influence of 
Temperature on the Electric Conducting Power of Metals.” 
It was this research which proved the important fact, that 
the conducting power of the pure metals decreased to the 
same extent between o° and 100° C,; two remarkable 
exceptions, however, to this law, Iron and Thallium 
were the subject of a later paper; “On the Specific 
Gravity of Metals and Alloys;” “On the Chemical 
Nature of Alloys,” in which he showed that nearly all the 
two-metal alloys may be considered as solidified solutions 
of the one metal in the other. Also a long series of deter- 
minations of the influence of temperature on the con- 
ducting power of alloys. He also made a most careful 
redetermination of the expansion of water and mercury, 
and found that Kopp’s coefficients were slightly too low. 
He was a very active member of the committee appointed 
by the British Association “ On the Standards of Electri- 
cal Resistance,” and it was one of the alloys discovered by 
him which was finally adopted for the reproduction of 
the now well known B A unit of electrical resistance. His 
later chemical work is emhodied in a series of papers in 
the Philosophical Transa:tions—* On the Chemical Con- 
stitution of Narcotine”—published partly in conjunction 
with Prof. Foster, and partly with Dr. Wright. In these 
he shows that one, two, and three atoms of methyl can be 
successively removed from narcotine, and also describes a 
large number of interesting derivatives of the same. In 
1869 he was appointed Professor of Chemistry in St. 
Bartholomew’s Hospital, and in the same year received 
the Royal Society's Gold Medal for his published re- 
searches on the metals and the opium alkaloids. One of 
the most important results of his last investigation is the 
discovery of the relation between morphia and codeia, the 
latter simply containing one of methyl more than the 
former ; although, however, he succeeded in obtaining 
| ; : 
apomorphia from codeia, he was never able to reconvert 
apomorphia into morphia, and thus form morphia direct 
from codeia. At the time of his death he-was occupied 
with the experiments’on the chemical nature of pure cast- 
iron, of the Committee appointed to inquire into which he 
was a member, and also with experiments with a view to 
determine whether the specific heat of platinum was con- 
stant at high temperatures, and if so, to employ it in the 
construction of a standard pyrometer. He was also pro- 
secuting his researches on the opium bases, and had 
already arrived at interesting results, which we believe 
will shortly be published. All the beforementioned re- 
searches display an enormous amount of manipulative 
skill, and there is little doubt that his success was mainly 
due to the wonderful acuteness of his powers of observa- 
tion, and also to his great perseverance ; but it is indeed 
surprising that, labouring under the physical disadvantages 
he did, he should have been able to attain such ends. 
At atime when England can least afford it, she has 
lost one who had not only done a vast amount of valuable 
work, but who, there was every prospect, would do as 
much more in the future. 
BRITISH EDIBLE FUNGI 
] USHROOMS and their congeners seem never 
have been in good repute since Agrippina em- 
ployed one of the tribe to poison her husband, and Nero 
with villanous pleasantry called it the “ food of the gods.” 
With proverbial tenacity the bad name thus incurred has 
clung to the whole family of agarics, and what within 
certain limits might be called a wholesome dread has 
become a deep-rooted and irrational prejudice, excluding 
from popular use a really valuable class of vegetable 
esculents. We cannot altogether go along with those 
enthusiastic mycophagists who recognise a substitute for 
meat in every edible fungus, and dilate on the ozmazome 
and other nutritious properties of the tribe ; but we readily 
acknowledge that their merits as secondary sources of 
food-supply have hitherto been unduly neglected. The 
great difficulty always felt in advocating the claims of 
the class to more extensive use has arisen from the want 
of some definite rules, some formula at once simple in 
expression and universal in application, by which to dis- 
tinguish the noxious from the innocent members. Pliny, 
in his Natural History, goes so far as tosay that the first 
place amongst those things which are eaten with peril must 
be assigned to agarics, and he expresses his surprise at the 
pleasure which men take “in so doubtful and dangerous 
a meat.” But his observations show that fungi of all 
sorts, including even such growths as the F/zs¢ulina 
hepatica, were known to his countrymen and eaten by 
them without scruple. Indeed, in one particular the wis- 
dom of the ancient Romans seems to have been superior 
to that of their descendants, for, while Horace lays down 
the rule— 
Pratensibus optima fungi 
Natura est ; aliis male creditur— 
the modern AZdiles of the Roman market condemn to in- 
stant destruction every specimen of the meadow mush- 
room (A. campestris) which comes within their reach. 
Although, however, it is not always easy to distinguish the 
wholesome from the unwholesome fungus, and the organs 
of sight and smell require some training before they can 
be wholly trusted in the matter, yet the dangers have been 
greatly exaggerated, and, as a matter of fact, hogweed is 
more often mistaken for parsnip and aconite for horse- 
radish than are Boletus sdétanas and Amanita verna for 
their innocent brethren. No better opportunity for en- 
gaging in the study of this branch of natural history could 
be found than that which the present season affords ; and 
if the treatises of Mr. Berkeley, Dr. Badham, or Mr. 
Worthington Smith be not at hand, the following notes on 
Oct. 27, 1894 
