Amador ledger., 1907-07-26

The effect of grass on tree growth
has been studied in England, at the
Woburn Experimental Farm, for
seventeen years. Spencer Pickering
reports that in general various grasses
Ietard the growth of fruit and ot10I
trees over whose roots they may be
growing, and in the case of freshly
planted trees the action is decidedly
Injurious or even fatal. Experiment
has shown that the effect cannot be
due to abstraction of food or moisture
from the soil, nor to influence on soil
temperature or on the gases contain
ed, nor to the formation of acid or
elkalI. Some poison produced by the
grass-directly or through bacteria
may affect the tree roots, but the
latest experiments make it appear that
the real influence is due to the kill
ing by the grass of the root bacteI ia
that in some way promote the tree
growth. The roots seem to owe their
function to bacteria action-a con-
clusion of great and tar-reaching
significance, if verified.
Vary the routine of daily labor by
cultivating a scientific hobby, is the
advice of Prof. S. p. Thompson, who
reminds Us that much of the world s
scientific work has been done by
amateurs. For instance William Her
schell, the astronomer, was a music
teacher; William Gibbert, author of
DE Magnetic, was medical man, DIR.
W. ID. DalJ1Dger, authority on the
microscope, was a clergyman; ana
William Sturgeon. inventor of the
electromagnetic, was shoemaker.
Observations of the spectrum of
Alpha Scorpii made at the Cape OF
Good Hope, have shown a puzzling
line that an English astronomer has
attributed to tin. If this proves to
be correct, it is the first discovery of
tin ever made in the atmosphere of a
STAR
Returns by the London Fire Brigade
show that the careless practice OF
dropping matches and other lights is
the most prolific source of conhagra-
tions, more than 81 per cent of the
3S43 fires which occurred in the
county of London last year having
been due to this cause. Not less than
257 fires arose from unprotected
lights, 148 from oil lamps, 81 from
Improperly set up stoves, SO from hot
ashes, and 235 from sparks from
CRATES. Gas leaks and the reckless
search for them with lights resulted
in l34 fires. Defective wiring for
electric circuits led to 100 fires, some
of them quite disastrous, but it is
believed that the new regulations and
safeguards urged upon architects by
electrical engineers will make quite
safe such wires as mayj be placed in
future.
The compressor" method of max
Ing foundations, which has been
under test for six or seven years in
Paris, consists in forcing a tapering
ram down to hard pan and then
ramming into the hole successive
layers of stones and rubble. The pro-
cess thus forms solid conglomerate
pile of the shape of an inverted mush-
room, with base four to six feet in
diameter. For ordinary foundations
one such pile takes the place of FIVE
or six wooden ones, and it will sup
port an enormous load without sink
ing or collaps1ng. In wet earth, clay
Is introduced around the hole to make
the sides water-tIght.
Half of the smoke cloud that the
London County Council is trying to
suppress Is believed to be due to the
ordinary domestic crate. In winter
on days when most business places
have been closed-the smoke of a
million domestic chimneys has been
seen to rise in solid bank 1000 or
1000 feet and drift with the wind to a
distance of so miles in such density
as to hide the sun. DIR. Shaw's esti-
mate is that one-half of London 8
sunshine is cut off by smoke in
winter and one-sixth in summer.
The difficulties of electroplating
with cadmium have been recently
overcome, thus opening up an
important use for the metal, which is
low obtainable at moderate price.
The best results have been obtained
from specially prepared cadmium
carbonate, carefully purified, although
the commercial salt has proven fairly
satisfactory. The cadmium carbonate
is dissolved in solution of potassium
cyanide, forming a clear, bright
yellow plating bath. and cadmium
plate is used for the anode. A per-
tect deposit is had with either hot
or cold bath, temperature of about
l25 degrees f. being preferred. The
coating, though soft, is harder than
silver, and the color is as white as
tin, but not so white as silver. The
surface, which takes a very high
polish is not readily furnished by
sulphuratted hydrogen or other
vapors.
One of the surprises of the time is
the conservatism of medical SCIENCE