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744 
added, and boil it during half an hour. Let it rest, 
decant, and the bath is ready for use. The wire to 
be covered with the insulating-skin is connected to 
the positive pole of the battery, and a small strip of 
platinum to the negative pole. Both wire and plati- 
num are then plunged in the bath. Metallic lead in 
a very divided state is precipitated at the negative 
pole, and peroxide of lead on the wire. 
of peroxide takes all colors of the spectrum, and the 
insulation is highest when the wire takes a brownish- 
black tint. If this insulator is durable, it will prove 
of great service in electric lighting. 
— The Society of naturalists of the St. Petersburg 
university have decided on affording means to three 
zoologists for expeditions in 1884. One is to study 
the fauna of the White Sea; another, the embryology 
and development of the genus Accipenser in the 
Ural River. The botanical and geological excursions 
will be discussed later on. 
—QOn May 19 Pasteur read, at the Academy of 
sciences, his report on his four years’ experimental 
studies on hydrophobia, and the means, not of eradi- 
cating, but of weakening it. The correspondent of 
the London Daily news describes Pasteur as ‘‘a man 
of square-built figure, and having the rather coarse 
and solid air which one so often finds in aristocrats 
and peasants in the Franche Comté, his native prov- 
ince. The eyes are so accustomed to the microscope 
as to have lost in great measure their normal capacity 
of visional adaptation, and are devoid of expression.”’ 
Pasteur admits, in his report on hydrophobia, that the 
microbe causing it has not been discovered, though 
he is sure of its existence; and that it may become 
again rebellious after it has been transmitted to an 
organism more favorable to its growth. Thus the 
virus inoculated from an ass to a rabbit will not kill 
the latter, but if passed on to another rabbit, and then 
to dog or man, will be fatal. He observed that in 
some animals the virus lost, and in others gained, 
force. In the rabbit its power was most visible, 
whereas the ape was less terribly affected. It there- 
fore occurred to Pasteur, that, if virus were trans- 
mitted from one ape to another, it would grow weaker 
at each inoculation. He took some from a dog’s 
brain, and inoculated an ape, which died from its 
rabid virus. He inoculated a second, and then a 
third, which was hardly indisposed. Th» virus so 
modified was transmitted to a rabbit, in whose body 
it recovered some strength. It increased in morbid 
power in a second and third rabbit, and attained the 
maximum in the fourth. It would thus be seen that 
virulence was only kept in check by withholding from 
it good conditions for growth. It would be also 
seen that it never recovered, when well tamed, its pris- 
tine deadliness in asingle bound. Pasteur claimed 
to so completely tame the virus, that a dog would, in 
being rendered refractory to rabies by hypodermic in- 
oculation or trepanning, show no sign of illness. In 
the second part of his report, Pasteur explained how 
the maximum of virulence was certainly attained, by 
making several guinea-pigs the mediums between 
rabbits and dogs. He told the academy he had dis- 
covered a process by which he can operate with 
SCIENCE. 
This layer — 
[Vor. IIL, No. 71. ' 
diseased blood on healthy blood, and claims to be ~ 
able to check the progress of rabies in freshly-bitten 
dogs or other animals. He asks the academy and 
the minister of public instruction to appoint a com- 
mittee to study his proof experiments. 
— One of the attractions of the London exhibition 
of hygiene is a street of old London, containing 
houses of various periods previous to the great fire 
of 1666, with the domestic arrangements of their 
time. Modern villa residences, as they ought to be, 
and as they ought not, also add to the interest of 
both tenant and landlord in what promises to be as 
great an attraction as the ‘ fisheries’ was last year. 
A correspondent of the New-York Evening post 
writes that the street representing old London was 
originally intended to be a life-like and life-sized model 
of Old Chepe, but it was found that no actual record 
of the locality remained. It was therefore decided 
to construct a street of celebrated and well-known 
relics, most of which have only disappeared within 
the last century. The work has been carried out 
under the superintendence of Mr. George Birch of © 
the London and Middlesex archeological society. All 
the buildings belong to a period anterior to the great 
fire. One enters by Bishopsgate through a speci- 
men of the old London wall: the arch is surmounted 
with the city arms, and a statue of Bishop William, ~ 
the Norman. In the street we find the Rose inn, 
Fenchurch Street; the Cock tavern, Leadenhall; the 
Three squirrels, Fleet Street; Izaak Walton house, | 
No. 120 Chancery Lane; and old shops from St. 
Ethelburga’s Bishopsgate. 'The street is narrow, and 
the gables almost meet over one’s head. A residence 
of the wealthy of that period is that of the Duc de 
Sully, also a house where Oliver Cromwell lodged in 
Westminster. There are examples of guild-halls, 
such as the Hall of the brotherhood, from Little 
Britain. Next we come upon the Old fountain hos-’ 
telry from the Minories,—a quaint, tumble-down 
edifice of four stories, each projecting further over 
the other, and a lean-to gable roof. Whittington’s 
palace is a fine specimen of the period. A full de- 
scription of the show by the designers appears in the 
catalogue. There are specimens of all the Eliza- 
bethan types, as also of old Roman decoration in plas- 
ter and terra-cotta. ‘The houses are peopled by figures 
dressed in the period from missals, old decorations, 
drawings, etc. Old armor, etc., has been lent, and 
the whole worked up into a most life-like show. The 
object is to give an idea of the hygienic condition 
under which our ancestors lived. 
— The New-York Evening post states that the 
Spanish papers are full of the proposal to cut a canal 
from the Bay of Biscay to the Mediterranean Sea. 
The plan proposed is to deepen the River Gironde for 
some distance, and reach the open sea at Narbonne, 
in the department of Aude. The proposed work 
will be about two hundred and fifty miles long, and 
will save a distance of nearly two thousand miles be- 
tween Suez and London. Speaking of two great en- 
gineering proposals, one paper says that the channel 
tunnel will turn an island into a peninsula, while the 
new canal will turn a peninsula into an island. 
