THE TROPICAL AGRICULTURIST. 
[ March i, 1895 
A' first rapid increase in the Alga) wis noticea'ile, 
but after the lapse of about three week* things 
ev (lently cime to a standst ll. 
The addi.im of more nitrate-free nutritive solution 
gave no result; but if only the merest trace of a 
i.itrate were added, there was an mmediate resump- 
tion of activity. 
Th-sse facts in themselves are very g od proof 
of the inabi ity of Cysloooccus to fix atmospheric 
nitogen ; but to make matters doub y mre, a 
careful chemical analysis was made This showed 
that there wat uo in"rease in nitrogen during all the 
weeks the A'ga) had been flourishing, and that 
accor 'i gly no i >t i of the stream of free nitr gen 
which had b ei constantly pissing throu th ihe 
apparatus had bi n "fixed" .S ) far, then, the first 
Alga which had boen put to th ■ test of experiment 
showed itself incipalolo of utilising atmospheric 
nitrogen. 
Kossowits di now turned to fresh experiments ch ton- 
ing a'gal cu'tures of sometimes one, sometimes 
several sueciei takm 'ogethe-; to all of these he 
added simultaneously soil-bacteria of mixed sorts. 
Th s apparatus employed was very n ar.y the same 
as that alove described. In these experiments lie 
desired to test the supposition of Berthelot and 
Winogradsky, who considered the p esonee of certain 
organic substances to be favourable to the fixa mii of 
nitr gen ; he ac ordingly arranged bis experiments 
in five pairs, both members of o ich couple having 
iden ical conditions, except that in the one a .-mall 
quantity of suga- (dextrose) was added to the nutri- 
tive solution, whilst in th • o her no organic compound 
was presen . O.ie sat was arranged with Cystococus 
and soil-baceria. a id t e results o it lined showe I 
that in the absenco of organic materials a s n ill 
but yet 11 iticeab e increase in the nitr > eh of the 
system had taken place (from 2o m, r . to :i l mg.) 
Where su;ar had been previ iltsly adde I, however, there 
were three timos as much ni rog'eh aflcr the experi- 
ment as before. In a sjco.id paw of c ilt res the Alga 
Btichococcus and certain has ena w ;re use.l, but lure 
in no case, either wi h or wit iou; stuar, wis there any 
increase in nitrogen. Tais shows th i* St chococ-us 
has iii itself no p >\ver of ni roge 1 fix lion. 
Another couple c ntained a mixture of severa' 
Algas, Noitoc CylinJr .sp r mini, o.'e., >nd certain -ioi!- 
bacteria. In this instance a very large lixition of 
nitrogen took place, b ith whore sugar was pr sent 
and where noi ; in fact, in the iomier case .the 
nitrogen was iucrei-ei more than ninefold. 
All these observations shed much light u on the 
Question of the relatio s exi-iing b tweeu A'gte, 
m cro-orgaaisms, and atmosp teric nitrogej. They 
show ; — 
(I) That at leist two Algoe— Cystococcus and 
Sttchococcus — p.-ss 'ss no " fixi g " powers in them- 
selves. 
''(•2) That many Algal, taken together with certain 
microorganisms of hs soil, do possess the power cf 
assimilating atmospheric ni rogei). 
(3) That this po*er is much increased by the 
addition of such organic substances as sugar. 
It should be noticed that among the ten cul'ures 
used in the second set of exp -riments, only two 
contained defiuit ly isolated algal species, viz. the 
cases of the two cultures of Cystococcus and soil- 
bacteria. 
It was just in this instance, mveovr, that it had 
been s 10 ni ilia 1 the Algse itself had no capacity 
for fixing atrn ispberic nitrogen. Accordingly, there 
could be little doubt that it was tHr >ugh the agency 
of the micro organisms that the "fixation" had taken 
place in these latter cultures. 
The e<pe iment's of Laurent and Sshloesing had 
shown tb.t if in a culture of Algae and bacter a 
end iwed with "filing" power-, the A'gse wer des- 
troyed, the bactot a lost partly, if n -t entirely, this 
capacity, which the mixture hal p s-.essed. this 
pointed olearly to the fact that there was sun cl ose 
relationship existing between the Algoe and micro- 
ti •ganisms. 
, There aro man? facts which seem to indicate tho 
nature of this relationship. 
Uerthelot found that the nitrification of the soil 
only took place as long as organic compounds were 
present; if these were exhausted, the nitrifying 
process ceased. Ciaulier and Drouiu aUo showed 
the importance which organic compounds have with 
respect to nitrification Kossowitsch's own experi- 
ments, in which the advantage of adding sng »r t > the 
culture was shown, also point in the -aixe direction. 
From such observations at these, Kossowitsch 
coucludes that th • relati oiiship which the Alga; bear 
to 1 he micro-organisms is one connected with the 
organic, food Nippy of these latter; he thin'-stliat 
the Algce, furnished with nitrogen by the bacteria 
assimilate c irb ihydratu material, part of which goes 
to their own m imtetiance. but part also to that of 
the in'cro-organisnifs. It is, therefore, in his belief, 
an instance of symbio.-is in which eatdi supplies the 
wa Is of the other. There are ni my facts, partlv 
the result of his own observalia in, partly ihe result 
of th s ' of others, which uphold Vhis rinm. If the 
mixed culture be placed in the light, tlksre is a far 
more notice Uo e nitrogen increase tha'i when in 
darkness. Again, if a rich supply of carbon dioxide 
gas be provided, this is marked by a decided rise 
ii nitrogen-fixing powers. Both 'hesi conditious a r e 
sach as are known to influence carbohydrate a*aimi- 
tation chlomppyll- ontaiuing orgaaUuis; bat all 
experience is antagonistic to the view that light 
sh >u d be beneficial to the vital activity of the 
bae'eria, and there ar only one o<- two exceptional 
itista ces (Xitronunas, &c.) in which carbon dioxide 
can be directly assim latcd by these ni cro-oigaoisuis. 
Moreover, in the case where the bacter a are 
b ought into inline Jia e contact with Ihe Alga, as 
iu those species of Algui which are enveloped in a 
geliti ous covering wherein the raicr ■. rganisms 
become emhedd:d, nitrogen fixation a pear* to be 
greatly aided, and the ad lition of sugar to the culture 
has uo such inarke i ellecl as in the in-tances where 
none- jelatiiio s AL'Bb are employed. The expl < nation 
of his seems to be that in. bac eria, embedded in 
the gelatinous s ie ith are amply prov ded with 
c irbo.iydrate 'o d without ths additio ■ of sugar, 
whi h, toeref ire, conies more or less as a superfluity. 
All this seems to justify Kossowitsch's view of tlie 
part played by the Algae in the fixition of nitrogen; 
it app ars ti snow that they have an indirect, but 
none the less import nt, influence up >n the process. 
This is roughly the ex entof Koasuwitob's article; 
it has be^-ii impossibl to give here its detaj's, the 
bare outlines of his researches could alone be men- 
tioned, but t is hoped that sufficient has he<>n said 
to show the importance of his w> rk, perhaps even 1 1 
indicate the nlerest which every page of his memoir 
p issesses, dea'iu* as it does with one of the most 
fasciuating branches of vegetable physiology. 
Rudolf Beeh, 
— Xattiic. 
COLONIAL CHEMISTRY: 
NATIVE DRUGS AND SOIL ANALYSES. 
AGRICULTURE AND CHEMICAL PHYSICS. 
The Government Chemist (Mr. Ei Nevill, Fellow 
of the Institute of Chemistry), reports for the year 
1893-94:— 
There have been made for Government Departments 
37 analyses, assays, and other analagous examinations, 
being scarcely a fourth of the average of former years. 
Tivo o' the toxicological investigations were cases of 
suspected p >iso ing by me ns of arsenic, and the 
analyses rendered it absolute ly c rtain that the deaths 
had not resulted from arsenical poisoning. A number 
of reports h vo bee i furnished for the info matio 1 
of the G ivernmout on variou technical subjects. As 
the oppir unity has offer, d investigations have bee i 
made on su ije ts ultimately counected with the progress 
of the (Jolony, especially in connection w th coal 
mining aud agriculture. A number of expjriments 
have been m de on best methods of utilising the 
various hard anthracitie coals fouud iu ihe ! olouy 
for th. j pu'p ,si of n.tvsl use, so as to give the maximum 
