Feb. 20, 1873] 
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NATURE 
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303 
system the opposed propositions, which do show their subject to 
be unreasonable, are intended to do duty as contradictories. But 
in Kant’s system the opposed propositions in an antinomy are 
only seeming contradictories, are virtually contraries, and their 
common subject remains the subject of an intelligible propo- 
sition, and one that Kant believes himself to have substantiated, 
after the contraries are invalidated: so that the subject is after 
all amenable to the processes of human thought, though not 
representing an object of experience. I dare not further trespass 
on the columns of NATURE to comment upon Prof. Clifford’s 
views of the two legs of Kant's philosophy! Certainly the one 
leg is wholly due to my opponent’s “exuberant imagination :”’ 
it is Hamilton’s leg, not Kant’s. 
Athenzum Club, Feb. 17 
C, M. INGLEBY 
Inherited Feeling 
THE remarkable case of an inherited feeling of dislike for a 
special class of persons, communicated by Mr. Darwin, appears 
to me to support a view I have long held (but not yet published) 
as to the explanation of another class of so-called instincts. The 
three separate instances given in which the dogs showed a violent 
antipathy to butchers, either without seeing them or when they 
were dressed as gentlemen, clearly indicates that it was through 
the sense of smell that the painful sensation was experienced ; 
and this is quite in accordance with the wonderful delicacy and 
importance of this sense in most animals, and especially in dogs. 
It is natural to suppose that some ancestor of these dogs was 
tematically and cruelly ill-treated by several butchers, perhaps 
rom some thievish propensity or other bad habit which required 
frequent punishment, so that the smell of a butcher came to be 
invariably associated with pain and a desire for revenge. But 
the most important fact to observe is, that there must be some 
_ peculiar edour developed in human beings by constant contact 
with flesh, which a dog can recognise apart from individual 
peculiarities and in spite of perfect disguise. Now the power 
many animals possess to find their way back over a road they 
have travelled blindfolded (shut up in a basket inside a coach 
for example) has generally been considered to be an undoubted 
case of true instinct. But it seems to me that an animal so cir- 
cumstanced will have its attention necessarily active, owing to 
its desire to get out of its confinement, and that by means of its 
most acute and only available sense it will take note of the suc- 
sessive odours of the way, which will leave on its mind a series 
of images as distinct and prominent as those we should receive 
by the sense of sight. The recurrence of these odours in their 
proper inverse order—every house, ditch, field, and village 
having its own well-marked individuality—would make it an 
€asy matter for the animal in question to follow the identical 
route back, however many turnings and cross-roads it may have 
followed. This explanation appears to me to cover almost all 
the well-authenticated cases of this kind. 
- ALFRED R. WALLACE 
I Am able to corroborate the remarkable fact mentioned in 
Dr. Huggins’s letter in your last. 
My father possessed a mastiff, a son of Sybil, daughter of 
Turk, who has, ever since he was a pup, evinced the same 
antipathy to butchers. We have hitherto been unable to explain 
it, for he is always perfectly good tempered with other trades- 
men who come to the house. The butchers have, on several 
occasions, tried to propitiate him by throwing him presents of 
meat, but although willingly enough received, ic has done 
nothing towards abating his hostility. H. G. BRookE 
Hale Carr, Altrincham, Feb. 15 
I HAVE a cat, of a long-haired breed, whose aversion to dogs 
_ is unusually strong. Last autumn, six kittens of hers, under 
‘two days old, were ina corner of the kitchen where they had 
had no opportunity of making acquaintance with any dog; 
yet, on being stroked (in their mother’s absence) by a hand 
which a dog had just licked, more than one of them ‘‘ swore” 
violently. This was repeated several times, but the little crea- 
tures showed no dislike to being touched with a clean hand. 
: A LovER OF ANIMALS 
Two or three months ago I was walking with my two little 
girls near the railway bridge at West Kensington, when the 
children (who always find the attraction of a fine dog irresistible) 
made me stop to admire a tall and remarkably handsome mastiff, 
2pparently the property of a man who stood by with a hand- 
barrow. He wasspeaking to two other men of this dog, and of 
another of the same kind which he had at home, and telling 
them that they were quiet and amiable to all men but butchers, 
and that it was not safe for a butcher to come near either of 
them. One of the men said that he believed all dogs of that 
breed showed the same antipathy ; and added that wh-n they 
were left loose at night to guard premises, they would always 
allow a policeman to enter. 
This chance conversation is perhaps hardly worth troubling 
you with, as I have no means of ascertaining whether these dogs 
claimed kindred with Turk, but I send it to you, nevertheless. 
Kensington Square, Feb. 17 
EFFECT OF LIGHT ON SELENIUM DURING 
THE PASSAGE OF AN ELECTRIC CURRENT.* 
EING desirous of obtaining a more suitable highresis‘- 
ance for use at the Shore Station in connection with 
my system of testing and signalling during the submersion 
of long submarine cables, | was induced to experiment 
with bars of selenium,a known metalof very highresistance. 
I obtained several bars varying in length from § to Io cen- 
timetres, and of a diameter from 1 to 14 millimetres. 
Each bar was hermetically sealed in a glass tube, anda 
platinum wire projected from each end for the purpose of 
connection. 
The early experiments did not place the selenium in a 
very favourable light for the purgose required, for although 
the resistance was all that could be desired—some of the 
bars giving 1,400 megs. absolute—yet there was a great 
discrepancy in the tests, and seldom did different operators 
obtain the same result. While investigating the cause of 
such great differences in the resistance of the bars, it was 
found that the resistance altered materially according to 
the intensity of light to which it was subjected. When 
the bars were fixed in a box with a sliding cover, so as to 
exclude all light, their resistance was at its highest, and 
remained very constant, fulfilling all the conditions neces- 
sary to my requirements ; but immediately the cover of 
the box was removed, the conductivity increased from 15 
to 109 per cent. according t» the intensity of the light 
falling on the bar. Merely intercepting the light by pass- 
ing the hand before an ordinary gas-burner placed several 
feet from the bar increased the resistance from I5 to 20 
percent. If the light be intercepted by rock salt or by 
glass of various colours, the resistance varies according to 
the amount of light passing through the glass. 
To ensure that temperature was in no way affecting the 
experiments, one of the bars was placed in a trough of 
water so that there was about an inch of water for the 
light to pass through, but the results were the same ; and 
when a strong light from the ignition of a narrow band of 
magnesium was held about nine inches above the water 
the resistance immediately fell more than two-thirds, 
returning to its normal condition immediately the light 
was extinguished. 
PARTING BANQUET TO PROF. TYNDALL 
ON the evening of February 4 Prof. Tyndall's visit to 
the United States was crowned by a banquet at 
Delmonico’s, New York, at which there were present 
about 200 of the most distinguished citizens of the 
country, presided over by the Hon, William M. Evarts. 
Among the company present were the following :—The 
Rev. Dr. Bellows, Parke Godwin, Dr. Draper, A. M. 
* Communicated to the Society of Telegraph Engineers, February 12, 
by Mr. Latimer Clark, from Mr. Willoughby Smith, Electrician to the Tele- 
graph Construction Company. 
