January i, 1892.] 
THE TROPICAL AGRICULTURIST, 
477 
of the nature of the substance of which he was 
the fortunate owner. The barrolful proved to be 
ambergris of very fair coinnieroial quality, and 
was disposed of with osreful management, at the 
full market value of the day, the broker wisely 
*f>nting to anyone until the last piece was 
Bold how groat was the quantity entrusted to his 
care, for fear of spoiling the market. 
The greater part of the ambergris sold in London 
during the last lew years has boeu that obtained 
by the New Zealand and Tasmanian whalers who 
ply their trade in the Antarctic Ocean. Whale, 
nshiug Was once an important industry in Tasma- 
nia, and quite a large fleet of whalers was owned 
by Hobart firms. Now the Tasmanian industry has 
practically ceased to exist, and there is no bops 
of its revival. New Zealand still possesses fisheries 
of some importance, and will probably continue to 
supply our market with much of its ambergris for 
Many years to come. Meanwhile spermaceti whales 
are getting scarcer year by year, and the lime may 
soon come when the scarcity of ambergris shall be 
chronic instead of spasmodic. It is to bo hoped 
that before that date science will have taught us 
how to supplant nature in the production of amber- 
gris ; but at present there are no indication what- 
ever of an efficient synthetic substitute — Chemift 
and Dmggist. 
notes on populae science. 
Ev Dn. J. E. Tavi.ok, f.l.s., k-o.s., &o., 
Eniion OF •' Sciknck Qo.ssir . " 
B liley, an American Ijotivuist, has been 
porting on the cxperimiuts receullv maUe at the 
"‘1** Cornell University with 
^ M^aB.sor Lodge, one of our own most 
wm" a-”’ showed that the 
Sished m A Report on fog jnst 
hLlthi » . '’•'“onB'ratea how iuj.ii-ions it is to plant 
if WO oon.dispel fog, and at the 
same imie shmulate the growth of plants by electricity, 
tile fatter will be donbly useful. Professor Bailey’s 
experiuiouts were made during January, Febnrary, and 
March, one forcing-house being exposed to (he normal 
fight of the sky during daytime, and illiiminato i by 
e eotrioity at night. Another forcing-house containing 
dilferoT" ^'"?i ‘‘t 'ii'io 
' 1 *’^“ ”'‘® “> Morked that the 
experiments have been continued this year with a 
vimv to noting the effects on colonr, 
iwo ai^Htinguisbed Frt*noh chemists have just read 
a paper before the Paris Academy of Scienros on the 
i roper Odour of Barth. ” Everybody in the country 
IS well acquHioted with tlie delicious smell the earth 
yields after a shower of nin. This is uow found to 
V* opgauie coraponud of the aromatic 
irtiuuy. Its odour is very penetrating, ami aoalogois 
Wol.l Its proportion io the sol is, 
a few millionths of a grain— indeed, 
one Ihrecmillmuth gives a decided smell. The new 
principle IB neither acid, alkali, nor a normal aldehyde. 
Its concentrated aqueous solnt ions may be precipitated 
by carbomate of potassium with the production of a 
resinous ring. When heated with potash, an acrid 
odour analogous to tlut of the resin of aldehyde is 
deve oped. Under cittam conditions, such as by the 
employment of potash and iodine, iodiform is produood. 
Tins property is common to ,n,ny other substarioes, 
but aloohol, acetone, &o., were not found during the 
experiments just mentioucJ, although some cboniiala 
sta^ they have been met with in vegefable mould, 
Here w good news for potato growers. It has long 
bcon known that a solution of sulphate of copper 
checked mildew in vines, and an experienced French 
agricultural chemist determined to try the offeots on 
‘he allied species of funpua which causes potato 
disease. Ho has been trying it on the potato plants 
lor two summers past, and has recently published a 
lengthy statement of the experiments, wliich are of a 
very remarkable character. He sliowa that an appli- 
cation of suipbiite of copper not only checks the ravages 
of the disease, but vastly inert ases the crop — in some 
iustaiicca to the extra vcluc of i'fi an acre. 
The fasoioatiog ard importaut problem as to the 
acquisition of nitrogen from the atmosphere bv plants 
is still occupying the atlentioii of chemists, lioth in 
ti is country, America, and France. In the United 
States two eniinout investigators have arrived at the 
conclusions tbat atmospheric nitrogen is undoubtedly 
acquire! during the growth of peas and alfalfa, aud 
that the amount of nitrogreri gained inercaaos with 
the number of root tubercles. Further, that the 
addition of soil-infusion is not necessary for the pro- 
duction of root-tubercles — a fact which may bo aoooiiuted 
fur by supposing that the mioro-orgauisms or their 
spores exist iu the air, and are deposited iu the pots 
wliere the planks grow. Oereala do not. as a rule, 
manifest ilia power of acquiring the nitrogen from 
the atmosphere, nor are rout-tubercles forniod on them, 
as ill the case of leguminous plants. The latter fact 
disproves the statoment recently made by a French 
Bgrieultiiral chemist, that cereals have the power of 
absorbing atmospheric nitrogen. Frofessor Oilhert has 
also arrived at the coucinsioo that free nitrogen is 
fixed lothocourie ot the development of the urgaiiisms 
within the nodules, and that the resulting uilrogenoas 
compounds are absorbed and utilised by such leguminous 
liost-plants as the common red clover. 
Ur. John Murray has read another paper before the 
iioynl tiociety of Edinburgh on the much-disputed 
subject of silica and siliceous formations in modem 
seas. The facta are of great interest to goologieta 
generally. There is greit diffioulty in acooimting for 
the number of organisms which secrete silicic aoid, 
and for the remains of such urgaiiisms which occur 
in ami on the bed of the ocran. The amount of silicic 
acid which exists in solution in ses-walcr is far too 
small to account for the immense development of suoli 
organisms in various parts of the ocean. Ur. Murray 
and Mr. Iivinu liave proved that clay aud mud carried 
down by rivers to the sea are to be found in even 
the least disturbed parts of the ocuau. Uiatoms esn 
extract from these clays euffioieiit material for the 
formation of their tliuty sholls. — AustrcUcu/iaii, 
HOW TO SET A HEN. 
It may seem to he an easy matter to many to do 
tills seemingly simple piece of work, but it is iiidoed 
a thing that requires fircthougbt, experience and great 
care. To sot a ben so as to secure belt results is 
indeed no child's play. In the first place, bo sure 
your heii wants to sit. Then be sure she is iu a good 
location ; if not, move her to ooo. If she can be set 
on the ground, you will find it to be the very place ; 
if not, out a so.f, turn it over, ecnop out a dish like 
place, ihcu put the sod in a box, grass side down. A 
nest made iu this way will hold moisture— one of the 
roiBons why a hen sitting oa tho ground always 
hatchos iietter than when up in a building. Sprinklu 
a little litter over the nest and put io your eggs. 
Always have the nest arranged so ihst the hen can 
walk on and not fly down upon tho eggs. If you breed, 
the heavy varieties tho best nest can be made by turuiug 
down a barrel witli only one head out and scooping 
out a place iu tile ground so the barrel may be sunk 
in the ground a litllc. The boos can then walk on 
their eggs without danger of breakage- The ground 
Will help to secure moisture for the rggs, aud you 
can olose the open end of tho barrel every night, 
preventing rats Irom interfering. Take the hen off 
every day or two to give the eggs an airing, if (ho 
hen doea not go oft' on her own account. 
Be sure and set your hena in auob a nay thai others 
oiiuuot interfere. Murk the eggs, so that if others 
lay with tlio hcii you can remove the fresh ones. 
After a week, test the eggs to see which are fertile 
and which are not. It is not your policy to have in 
till! Dost eggs that will not hatch. After removing 
the niirniitfnl eggs you can replace them with fresh 
ones, marked, and upon the first ones hatching, the 
