August l, 1898.] THE TtlOPICAL AaEICULTURISf . 
I have said that there was nothing to show 
or indeed to make us suppose that the natural 
formation of nitrates Roiiig on in om soils was 
less tliaii in Europe, and the only thing this cor- 
n^spondent has been able to urge there against is 
t!iat on steep land and with a tropical raifvlall part 
ottiie nitrates may get -w ashed away. How does 
tilts eam]3are with my own statenient, viz , [ do not 
mean lu iiiiply tliat ail the niirates formed in the 
soil are pure gain fur the plants. Adinittii.g, how- 
ever, for argument's sake that haifoftl'.d nitrates 
formed are washed away — wliieh I think is rather a 
large concession to make— there would still remain 
say 441b, of nitrogen per acre, capable of producing 
800 lb. of teq. Does his argument then take any- 
thing away from my contention that under certain 
conditions the natural sujiply of nitrates — which we 
can besides augment artificially by loosening the 
soil— is sufficient to produce ample crops? 
Your correspondent has tried to make out an 
inconsistency between my theory and the fact 
of ray offering for sale nitrogenous manures ; 
but is tiiis not rather jjroof that I am not per- 
sonally prejudiced on this nitrogen question and 
that my writings have had their main object in an 
attempt to benelit and assist tlie planting industry ? 
■'' Ex-Planter " points to the results that have 
been obtained by the application of nitrogenous 
manures. Have I disputed or minimized these 
facts, though I have plenty of letters to show 
that the application of nitrogenous manures has 
not always proved an unmixed ble.ssing. But is this 
application of nitrogenons manures the clioapest way 
to prod ace our crops ? That is the real question 
at stake. It is easy enough to produce large 
crops, if the question of cost has not te be con- 
sidered, but my letters, as tl eir headings de- 
note, bore on the subject of cheap production, 
a fact seemingly overlooked by this correspon- 
c'ent, but which will bye-and-bye be fully ap- 
preciated by those going in for practical trials 
and supplying those fertilising ingredients, 
which are actually deficient in soils. 
Let us for one momeiit consider the meaning 
of the mauurial percentages recommended by 
Mr. John Hugiies for up-countrj' estates. The 
application ot 4 cwt. of a mixture containing 
4 per cent nitrogen, 9 per cent phosidioric acid, 
and 13 J per cent of potash, is equal to 16 lb. 
nitrogen, 36 lb. phosphoric acid, and o4 lb. 
potash. The phosph(nic acid, as tlie dominant 
manurial ingredient, is therefore sutlicient to pro- 
duce over 4,000 lb. of tea per acre (400 lb. tea 
t» every 31b. phosphoric acid), but the nitro- 
gen would bardiy suffice for 400 lb. of tea, 
and reliance is therefore placed upon the 
natural sources of nitrogen to make up the defici- 
ency. Practically this in no way differs fioni what 
I'maintaiu '? Mr. John Hughes has given it as 
his ojjinion that 4 per cent nitrogen in a manu- 
rial mixture should prove sufficient for most 
Ceylon tea estates and T dare say that Mr. 
Raniber's i-econimendations will hardly be much 
at variance with those of his colleague. 
Should "Ex-Planter'" care to gise us the 
benefit of his fnrtlier criticisms, lot him throw 
off his tmm-de plume and write over his own 
name. — Yours faithfully, A. BAUK. 
MANURING TEA: THE "NITROGEN' 
QUESTION AGAIN. 
June 30. 
Sir, — If " wrorg impressions have been created " 
hy my letter of the ]4th inst., it w;ir unkind of M. 
Baur, in the interests of the planters for whom he 
professes such concern, uot to have endeavoured to 
remove Ih'em sooner, and when he did make the 
attempt not to do so more thoroughly. 1 cannot see 
that he has tried to disprove any one of my asser- 
tions. If there is anything fresh in bis last letter, 
I hope, he will forgive ms for not being able to seize 
upon it. For my own p.irb I am not in'diued to 
trespass on the patience of the editor and his readers 
by carrying this correspondence much further, un- 
1p3s some obviously useful purpose can be served. 
But there are one or two points in M. Baur's last letter, 
wliicb I trust.Imay be ailov.-ed space to comment upon. 
Ill the first place, what is the " Nitrogen Question '' 
which he t'^kes credit to himself for having " brought 
forwaa-d " in ''a prominent fashion"? Appareutly 
the fact that nitrification is the result of micro- 
organic action and not, as was at one tim; snppoaed, 
a purely c)i6OTieal process. But this discovery was 
made more tliau 20 years ago, and M. Baur pays 
the planters and merchants of Ceylon a poor com- 
pliment in taking for granted that they are so hope- 
lesfdy behiiid the times, Bnt s;„y that all Ceylon, 
save lil. Baur, lay enveloped until lately in black 
ignorance on this point,, dot s M. B^mu- imagine that 
the eminent chemists who have from, time to time, 
recommended suitable tea fertilisers for India and 
Ceylon producei-s, are unaware of the important 
part played by the micro-organism ? It is refresh- 
ing to witness such a delightful display of naive 
vanity and unreflecting fervour at the end of the 
nineteenth century ! A fire with all the zeal of a 
recent convert Jvl. Baur is impelled to shout aloud 
his good new.'a from the housetops! M. Baur states 
that "under certain conditions" the natural supply 
of citrate:; is sufficient. But has he the least idea 
what these ''certain conditions" are? Could he, 
for instance visit an estate and say whether it was 
blessed with such happy "certain conditions?" If 
he cannot, of what practical value is thii loosely- 
worded pi.ragraph? Is M. Baur prepared to state 
definitely that the application of nitrogen in Ceylon 
has been excessive in the past, or that it is altogether 
unnecessary in some cases or in ail eases ? Why, if half 
the natural supply of nitrates is capable of producing 
800 lb. of tea, does Mr. Hughes recommend the 
addition of nitrogen sulHcieat for another 400 lb. 
of tea per acre? Presumably, even from M. Baur's 
point of Y!e-.v, because in Mr. Hughes' op niou, all 
the nitrate present in the soil is not readily avail- 
able as plant food. 
If M. Biur's offering nitrogsnous manures for sale 
when he believes them to be unnecessary, is proof 
of anything, it is surely rather of a disregard for the 
pockets of his clients than of his impeccable and 
unprejudiced attitude in the Uiatter. 
Nothing is easier than to insinuate that some vague 
system of manuring recommended, but not very parti- 
cularly described by iM. B^uir, is cheaper than all 
others, but nothing would be more difficult to prove. 
There is hog space for a long letter containing 
elaborate calculations in the coriespoudeiice column 
of a i^aper and M. B:rur probably relies on his 
assertion passing unehalieuged. But such ex-parte 
statements have no weight, and are in some degree 
their own refutation. 
If M. Baur had more experience of planting matters, 
he would know that no one interested in the industry- 
can aii'ord for one moment to "overlook" the " subject 
of cheap production." It goes without saying that it 
is a snbject constantly in our thoughts. 
Should any one wish to road a short but clear ex- 
position of the functions of the various micro-organisms 
engaged in building up the soil, I would suggest 
their perusing Dr. Aikniati's arlicle entitled "'Xhe 
Microbe in Agriculture" in the .June number of the 
" Nineteenth Century." I see no reason why 1 should 
abandon the iwni-dti pJame which I adopted fur the 
express purpose of eliminating the personal element, 
asfar as possible from the discussion. I have nothing 
to gain by advertising my ns.me. I do not pose as 
an authority. M. Haur lays down the law publicly, 
and I take it that anyone in the crowd has a right 
to answer him, — Your obedient s.rvant, 
EX-PLANTER. 
