FEBRUARY 14, 1907] 
MAD Oe: 
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specting dissociation and the dynamical equilibrium 
of molecules. How far this attempt will be ultimately 
successful time alone can show. Mendeléeff had little 
sympathy with the theory of electrolytic dissociation, 
which, he declared, was not in harmony with the facts 
of observation, and was of little use in facilitating our 
comprehension of the true nature of solution. Nor 
was he more predisposed towards the conception of 
electrons, although perhaps his belief in the integrity 
of the atom was hardly so fundamental as that of 
Dalton, who would have gone to the stake rather than 
recant his declaration: “Thou canst not split an 
atom!” 
The story of the rise and development of the Periodic 
aw is so well known that it is unnecessary now to 
dwell upon it. By a good fortune, which some may 
regard as evidence of predestination, Mendeléeff 
lived to see the verification of his predictions in the 
discovery, in rapid succession, of gallium, scandium, 
and germanium; and no seer ever prophesied more 
truthfully. It was the astonishing accuracy of Men- 
deléeff’s prognostications, and the apparent boldness 
and confidence with which they had been uttered, that 
profoundly impressed the whole scientific world, and 
secured for his generalisation a respect and acceptance 
for which otherwise it would have had long to wait. 
This generalisation is now woven into the fabric of 
modern chemistry, and is universally accepted as the 
only rational basis of classification. Like many other 
great natural truths, we are able, on looking back, to 
discern its germs in the tentative efforts of previous 
thinkers who more or less dimly appreciated the sig- 
nificance of the facts upon which it is based, but it is 
perfectly certain that Mendeléeff knew nothing of 
the prior work of De Chantcourtois and of Newlands, 
and was no more influenced by it than was Dalton by 
Richter or by the “ Comparative View of the Phlogis- 
tic and Antiphlogistic Theories” of William Higgins. 
In the memorable Faraday lecture which he gave to 
the Chemical Society in 1889, Mendeléeff, with a true 
nobility of mind and a modesty which revealed the 
real greatness of the man, gave adequate expression 
to his appreciation of the efforts of his predecessors, 
claiming for himself only courage and intrepidity in 
placing “the whole question at such a height that its 
reflection on the facts could be clearly seen.’ 
The Periodic Law has so far stood the test of expe- 
rience, and each new extension of the science is con- 
sistent with its previsions. The inert gases of the atmo- 
sphere find their place in the system, and the only radio- 
active substance the chemical properties of which have 
been sufficiently investigated has an appropriate posi- 
tion among its correlated elements. In the old days 
the followers of Stahl sought to make the conception 
of phlogiston an all-embracing doctrine. Mendeléeff 
anticipated these attempts as regards his own 
generalisation by showing that even the universal ether 
may be included within his system. In his last paper, 
published in 1902, entitled “An Attempt towards a 
Chemical Conception of the Ether,” he starts with the 
assumption that the ether possesses mass, and that 
it has an atomic weight many times less than that of 
hydrogen, something of the order of ro—* when H=1; 
that it is monatomic like argon and helium, and that 
by its small density and extremely rapid motion it 
permeates all matter and space. The ether thus be- 
comes, not an affection of matter, but a distinct entity 
capable of being attracted by elements in proportion 
to the weights of their atoms, and he held that the 
phenomena of radio-activity could be explained by the 
gradual emission of this ether from such substances 
as uranium and thorium which have the highest 
atomic weights of the elements. 
The truth embodied in the Periodic Law has led 
many to suppose that this generalisation lends sup- 
NO. 1946, VOL. 7§ | 
| 
‘under the guidance of Prof. Ricco, 
port to, and is indeed the proof of, the validity of the 
assumption of a primordial matter. Mendeléeff him- 
self declined to see that such an inference was warranted. 
He saw nothing in the law inconsistent with the idea 
of the individuality of the elements, holding that until 
it could be definitely shown that one element could be 
transformed into another, or that ether and matter 
were mutually convertible, the elements must be re- 
garded as distinct and separate entities, immutable 
and unchangeable. 
Mendeléeff not unfrequently visited this country, and 
was personally known to many British chemists, to 
whom he was always welcome. His tall and com- 
manding presence, his fine head, with its tangle of 
long, wispy white hair, his expressive features, his 
guttural utterance, the wisdom and originality of his 
talk, his shrewdness and sense of fun, all stamped 
him as an uncommon and strong personality, which 
immediately made its presence fe lt in any company in 
spite of the innate modesty of the man. Of wide 
liberal views, intensely national, and a great power 
in the University, Mendeléeff was doubtless a thorn 
in the side of bureaucratic Russia, and it was cur- 
rently reported that the frequent foreign missions on 
which he was sent were so many covert attempts to 
keep him at arm’s-length. 
Every scientific honour that this country could pay 
was awarded to him, and he was profoundly touched 
and deeply grateful for the sympathy and appreciation 
thus extended to him. On the occasion of his deliver- 
ing the Faraday lecture it fell to the writer’s duty, as 
treasurer of the Chemical Society, to hand him the 
honorarium which the regulations of the society pre- 
scribe, in a small silken purse worked in the Russian 
national colours He was pleased with the purse, 
especially when he learned that it was the handiwork 
of a lady among his audience, and declared that he 
would ever afterwards use it, but he tumbled the 
sovereigns out on the table, declaring that nothing 
would ‘induce him to accept money from a_ society 
which had paid him the high compliment of inviting 
him to do honour to the memory of Faraday in a place 
made sacred by his labours. 
Ty. BE: DHOReE: 
PROF. ANTONINO MASCARI. 
) Y the death of Prof. Antonino Mascari on October 
18, 1906, solar physicists throughout the world, 
and more particularly those who were his intimates 
in the Italian observatories, have sustained a severe 
loss. 
Born at Campobello di Mazzara (Sicily) on 
December 4, 1862, Mascari proceeded in due course 
to the University of Palermo, where he took the 
engineering course and obtained his degree in that 
faculty in 1887. It was while there that he developed 
the predilection for astronomical investigations, and, 
worked with that 
activity and intelligent ability which were the out- 
standing features of his whole career. He was later 
appointed to the position of assistant to the Piazzi 
Foundation, and thus was fortunate enough to be 
able to continue his association with Prof. Ricco—an 
association which has proved of inestimable benefit 
to the study of solar physics. 
In 1892 Mascari was appointed first assistant at 
the Observatory of Catania, where the solar promin- 
ence observations, commenced by Tacchini at Palermo 
in 1872, were continued. Probably only those who 
have had to use these Italian observations in dis- 
cussions of collateral phenomena are aware how well 
this task was performed, and how much the science 
of solar physics owes to the indefatigable labours 
