366 
NATURE 
[March 9, 1871 

a branch ofanatomy. But his great distinction was as a 
lecturer, and here his success was for a time unequalled. 
Like other teachers of the time, he had the advantage of 
introducing a great deal of comparative anatomy, physio- 
logy, and histology (so far as it was then known) into his 
lectures on human anatomy. He must have been gifted 
with great natural eloquence, and disdained none of the 
tricks of oratory. His biographer gives a wonderful 
account of the clothes he wore when lecturing, in what 
seems to have passed for “ full dress” in Edinburgh about 
1830, but also informs us that “the richest costume would 
hardly have availed had not the silvery tongue been 
brought into play.” Knox never drew diagrams, and 
equally rejected the help of ready-made drawings for his 
class, nor did he ever use notes. Above all, he thoroughly 
enjoyed his work. He left little written that is likely to 
preserve his fame. His translation of Milne-Edwards’ 
“ Zoology,” by which he is perhaps most widely known at 
present, is a bad specimen of his inferior work. The 
history of his life, besides its interest as the record of an 
able man’s remarkable success and as remarkable failure, 
is of importance from the light it throws on the study 
of anatomy in this country, on Scottish university politics, 
and on methods of scientific teaching ;~so that the inten- 
tion of the present work is more praiseworthy cae its 
PoS. 
execution, 
Strange Dwellings : being a Description of the Habita- 
tions of Animals. By the Rev. J. G. Wood, M.A., 
F.L.S. (Longmans & Co., 1871.) 
Mr. Woop’s works are well and favourably known as 
presenting the study of Natural History in its most attrac- 
tive form to the young. The present work is not new, 
being abridged from his “ Homes without Hands,” which 
obtained, some years ago, a deservedly large amount of 
popular favour ; and even in its original form it consisted 
of course mainly of selections from accounts given by 
travellers and naturalists. It is, however, extremely well 
suited to place in the hands of any boy or girl who is 
already fond of reading about strange animals, or whom 
jt is desired to interest in the study of nature. We find 
in it accounts of the curious trap-door spider of Jamaica, 
the bower-bird of Australia, with its remarkable edifice of 
twigs and shells, the mud wasps of Guiana, the repulsive- 
looking aard vark of South Africa, the weaver bird and 
tailor bird, and many other animals of singular habits, 
and illustrated with woodcuts, which combine with the 
lively style of the text to make the volume a very attractive 
one. 
The Duke of Edinburgh in Ceylon: a book of Elephant 
and Elk Sport. By John Capper, 777es correspondent. 
Illustrated with chromo-lithographs. (London: Pro- 
vost & Co., 1871.) 
Tus book is sufficiently described by its title, being a re- 
cord of the visit of the Duke of Edinburgh to Ceylon last 
year, and of his success in the colonial sports of elephant 
hunting and elk hunting. It appeals to two sections of 
the public, those who eagerly seize upon every incident 
connected with the mode of life of any member of our 
Royal family, and those who are equally eager after any 
description from life of sport in those countries where wild 
beasts worthy of a hunter’s rifle abound. We may quote 
the following as an instance of the perils encountered by 
our Prince in navigating the Cingalese rivers. “The 
stream was teeming with life. Fish of all varieties and 
sizes sprang into the boats as they paddled along, one of 
them finding its way into the Prince’s coat pocket” (loyal 
fish !) ; “on all sides could be heard the snapping of alli- 
gators’ jaws as tiny fish were caught in the monsters’ 
mouths. The party had proceeded about a mile down the 
stream, when one of them, leaning down and resting his 
head on the gunwale of the boat, was startled from his 
quiet rest by the apparition of an alligator’s gaping jaws, 
which made a direct snap at his head, fortunately missing 


it, but seizing, in place of it, the barrel of the rifle held in 
the hands of the Prince’s English attendant, who was 
seated nextto him, and which the monster nearly wrenched 
out of his hand, splashing the water about, and drenching 
every one in the canoe.” Is the Zzmes correspondent 
quite certain that alligators are found in Ceylon? 


LETTERS TO THE EDITC®2 
[The Editor does not hold himself responsible for opinions expressed 
by his Correspondents. No notice is taken of anonymous 
communications. | 
Lunar Halo seen from Two Stations 
I HAVE presented to the French Institute at its last sitting a 
copy of NaTuk®, January 26, with the sketches of a halo seen 
from Liverpool by two different observers from two stations 
at a little distance. It is the first time, as far as my knowledge 
goes, that we have had two different sketches of the same phe- 
nomenon. The difference is very considerable indeed, as a para- 
selene was seen by one of the observers, and not by the other. It 
would be very important to ascertain what was the exact situa- 
tion of each of them, and I should be glad if you can take the 
trouble to ascertain it by an inquiry through your paper. When 
I return to England I will ascertain the circumstances of the 
observation, which may lead to some definite conclusions on 
the form and altitude of floating snow during the night of the 
4th January. 
In my note to the French Institute, I say that, unquestionably, 
reflexion or refraction took place on several faces of crystalline 
snow, and each observer saw the refraction or reflexion on 
a particular face of crystal, placed conveniently for observation. 
So that double observation is very valuable, as affording a direct 
proof of the correctness of the explanations given by Mariotte, 
and others after him, of these magnificent appearances. 
According to Mariotte’s theory, the presence of a paraselene in 
one of the observations with the halo of 22° shows the presence 
of prismatic crystals, the faces of which must be hexagonal. 
The second appearance should, according to my opinion, show 
that these crystals were terminated by small pyramids, and the 
other observer perceived the halo reflected on the oblique face 
of these crystals. As he saw two or three halos almost concen- 
trical, it must be supposed that one of them was due to the 
upper pyramid and the other to the lower. 
Very probably the air was not disturbed by any wind, and 
elongated crystals were falling very slowly, or rather floating, 
owing to the smallness of their dimensions, which possibly may 
have been a small fraction of +) inch. 
I send you these suggestions only to direct further inquiries, 
and I make no pretension to exhaust the subject, which is very 
interesting. 
I myself observed on Thursday, February 12, what is not 
quite unworthy to be noticed, as showing how inexhaustible is 
the field opened by Nature to her inquirers. The sun was setting 
when J arrived at St. Pierre le Calais with my friend Alexandre 
Lille. I noticed the disc was distorted, the two partial suns 
being almost alike, and of a red colour. This appearance was 
se 
certainly owing to the air not being of a uniform density. Two 
different streams were separated by a horizontal surface. The 
truth of this supposition was very easily ascertained, as two 
different kinds of clouds were flying in two different directions. 
Neither of them was heavy, and the distinction was very ad- 
mirably made by the sun itself, which soon disappeared, leaving 
a rosy tint behind him. The lower clouds first presented a rosy 
colour, but soon became dark, and the upper clouds in their 
turn took the beautiful colour which the others below were just 
losing. The horizontability of the surface separating the two 
streams of air was a proof of great quietness in the atmosphere, 
and the night was magnificent, as well as the following day. 
W. DE FONVIELLE 
