THORPE’S ANALYSIS, ETC. 515

XLVIIL-Analysis of the Ashes of a diseased Orange Tree (Citrus Aurantium).

By T. E. TEORPE, Dalton Scholar in the Laboratory of Owens’ College, Mancheater.

THE orange plantations along the south-eastem coast of Spain, and in the adjacent Balearic Isles, have recently been visited with a severe epidemic, the rapid progress of which waB

Publ

ishe

d on

01

Janu

ary

1868

. Dow

nloa

ded

by S

tate

Uni

vers

ity o

f N

ew Y

ork

at S

tony

Bro

ok o

n 26

/10/

2014

02:

44:1

3. View Article Online / Journal Homepage / Table of Contents for this issue

516 THORPE’S ANALYSIS OF THE ASHES

naturally viewed with no little anxiety by the people, since the culture and exportation of oranges constitute one of their prin- cipal industries. This disease is said t o have made its appear- ance at Valentia, and t o have spread t o the islands during the summer of last year. The first symptoms of the sickening manifest themselves in the leaves, which turn yellow and in time drop fi-om the branches. During the progress of the disease, the roots exhale a most disgusting odour, arid within a very few days after the attack the tree succumbs. But the true nature of this remarkable disease, hitherto unknown in these parts, is very imperfectly understood; its origin is involved in complete obscurity, and as yet it has baffled all attempts a t remedial measures. Happily, however, its violence, which at one time threatened destruction to the entire plantations in the islands, has, within the present year, considerably abated, and the disease seems t o be gradually dying out.

For these particulars I am indebted to the kindness of Pro- fessor Bunsen, who visited the Balearic Isles during the summer vacation of last year, and as it appeared interesting to ascertain the nature of the inorganic constituents of the diseased trees, and t o compare it with that of the ashes left by the combustion of perfectly healthy specimens, procured all the necessary materials for analysis. Accordingly analyses of the ashes of the roots, stern, branches, and fruit were made in the laboratory of the University of Heidelberg, under Professor Buneen’s direction and superintendence. The results of these analyses form the subject of the present communication.

The following was the method of analysis adopted :-From 4 t o 5 grammes of the ash, obtained by burning in a muffle at the lowest possible temperature, were placed in a glass cylinder of about 500 C.C. capacity, provided with a well fitting stopper. About 50 C.C. of distilled water was then added, and carbonic acid passed into the cylinder, the delivery tube of the apparatus (which did not dip below the surface of the liquid) being fre- quently withdrawn, the stopper inserted, and the liquid shaken, in order t o promote the absorption of the gas. When the caustic bases were completely neutralized, and the solution saturated (which was evidenced by the cessation of the partial vacuum, and also by the bubbles passing “upwards” between the bottle and its stopper when the latter was cautiously lifted after vigorously slinldng the liquid) the total contents of the cylinder

Publ

ishe

d on

01

Janu

ary

1868

. Dow

nloa

ded

by S

tate

Uni

vers

ity o

f N

ew Y

ork

at S

tony

Bro

ok o

n 26

/10/

2014

02:

44:1

3. View Article Online

OF X DISEASED ORANGE TREE. 517

were washed into a porcelain dish, evaporated to complete dry- ness, again heated with a sinall quantity of water, just about sufficient t o dissolve the soluble portion, and after stanang R,

short time filtered through a weighed filter. The filtrat.e, together with the washings, was again evaporated nearly t o dryness, and allowed to stand for some time t o effect, as far a8 possible, the complete precipitation of the calcium sidphate, which was separated, and when its aniuunt was but small weighed immediately ; if large, it wits added to the main quantity of the insoluble portion of the a&, which IVXR then dried at 100" C. and weighecl.

1. Azcnlysis qf' the I t t ~ o l d d e Portioii.

In the insoluble portion are contained h e , niagiieaia, femk oxide, silica, plioaphoric, sulphuric, and carbonic acids. The carbonic acid was estimated by the usual method, that is, by determining the loss of weight which cz known quantity of the ash suffered on treutnieiit with clilute hydrochloric acid ; the sulphuiic acid was afterwards determined in this solutioii by precipitation as barium sulpliatc. The phosphoric acid was separated by means of tin. For its estimation, together with that of the bases and the silica, about 1 gramme of the inao- liible portion was dissolved in nitric acid, and after separation of the silica in the usual nirtnner, the solution was again evapo- rated nearly t o dryness, and dilute nitric acid added, until the bases were completely dissolved ; strong fuming i&ric acid was then added, until the calcium nitrate began to separate, when the slight precipitate was immediately re-dissolved by the addition of a few drops of dilute acid. The nitric acid solution of the bases ~vczs thus in the highest posfiible state of concentration, a i d on warining sncli a solution, the tin-foil is rapidly oxidized t o the niasiiniiiii degree of oxidation, Tvldst thc supernatant liquid remains perfectly clear. The prelimillary heating of t11e solution is absolutely necessary, sirice in the cold t8he metal becomes passive, aiicl refuses to oxidize. The yuaiitity of tin foil added amounted to about six tiines the weight of the phos- phoric acid that could possibly be present, and care was always taken to keep the nitric acid in sufficient excess, in order t o prevent the forination of the monoxide, w l k h renders the solu- tion inconveniently turbid. When a11 action w a ~ at an ~ x d . and

VOL. SS?. I -1 1'

Publ

ishe

d on

01

Janu

ary

1868

. Dow

nloa

ded

by S

tate

Uni

vers

ity o

f N

ew Y

ork

at S

tony

Bro

ok o

n 26

/10/

2014

02:

44:1

3. View Article Online

518 THORPE’S ANALYSIS OF THE ASHES

the tin fully oxidized, the contents of the dish were evapo- rated fiearly to dryness, in order to remove the excess of nitric: acid; water was then added, and the solution filtered. The precipitate contains all the phosphoric acid ; tlie bases are found in the filtrate, Thils precipitate, detached as far as possible from the filter, waa digested in the smallest possible quantity of highly concentrated potash-solution ; on the addition of watw thia mixture dissolves t o a perfectly clear liquid, provided no great excess of the alkali hag beeu employed. The trifling amount of the precipitate still adhering to the filter was dissolved in the same manner, and added to the main portion of the sohl- tion. The liquid was then saturated with sulphuretted hydrogen, acetic acid added in very slight excess, and the precipitated tin sulphide separated by means of Bu 11s c 11’s filter pump. The filtrate wag next concentrated t o a small bulk, the slight amount of tin sulplde, which invariably precipitates on evaporation, being removed, and the phosphoric acid determined in the usual manner as magnesium pyrophosphate. This slight departure from the indirect method usually enzployecl is only renclered possible by the aid of the filtering apparatus iiivciitecl by Buns en ; it liaa the advantage that the whole of the phosphoric acid admits of direct determination, a point of some iniportaiice when its amount is but relatively sniall, aud moreover the saving of time it effects is considerable. Tlie filtrate from tlie tin oxide, containing the ferric oxide, lime, and imgiiesia, may also con- tain no incoiisiderable quaiitity of foreign metals, for example. lead and copper, existing as impurities in the foil ; tliese were removed by mlphuretted hydrogen before the determiiiation of the bases, which were then separated in tlie usual way, tlie iron by ammonia, and the lime and niagiiesia respectively by mirno- liiuni oxalate aiid socliuin phosphate,

II. i-lnctlysis of the Soluble Portion.

The solutioii of the soluble portion of the ash was filtered from the calcium sulphate (separated by evaporat,ioii in the manner above described) through as sinall a filter as possible, into a weighed flafirk provided with a tubulus drawn out a t tlie side, t o admit of the more convenient weiglring off of aliquot portions of the weighed liquid. The total quantity of liquid was divided as near a8 possible into six equal parts, to serve for

Publ

ishe

d on

01

Janu

ary

1868

. Dow

nloa

ded

by S

tate

Uni

vers

ity o

f N

ew Y

ork

at S

tony

Bro

ok o

n 26

/10/

2014

02:

44:1

3. View Article Online

OF A DISEASED ORANQE TREE. 519

the determination of the sdphuric acid, alkalies, chlorine, aolu- Ble pliosphoric acid and carbonic acid, the sixth portion being reserved 111 case of accident.

The carbonic acid was determined volumetrically by & normal dphur ic acid and litmus solutions; the sulphuric acid and chlorine in the ordiiiary way, by precipitation as barium sixiphate :tnd silver chloride, and the phosphoiic acid separated after con- siderable concentratiou of the solution, as the double salt of Inagnesium and ammonium, and weighed as pyrophosphate. In order t o determine the amount of the alkalies, the aolutiofi was boiled with excess of baryta-water in a porcelain dhh, filtered, and the excess of baryta removed by ammonium carbonate ahd ammonia; the solution wag then evaporated t o dryness in a platinum dish, gentlyheated, re-dissolved in a few drops of water; ammonia and ammonium carbonate again added; and after Mtandizlg a considerable time, the solution was again filtered and evaporated t o dryness, heated, and by the cautious addition of' liydrochloric acid, converted into chlorides, in which forin the alkalies were weighed. The potassium chloride was then sepa- rated in the usual way by platinum chloride. In cases where the amount of the soluble portion of the ash was comparatively large, iuore than traces of magnesia ntill remained in solution with the alkaline chlorides, even after repeated treatment with ammo- iiiuiii carbonate and ammonia. This small quantity of magnesia w w found in the filtrate from the double Bait of potassium and platinum; its amount was easily estimated by evaporating the alcoholic solution to dryness, re-dissolving in water, and transfer- ring the aolution t o a small flask provided with a tightly fitting cork, pierced with two holes, t o admit of the introduction of glass tubes. This little piece of apparatus has the disposition seen iii the annexed figure. Hydrogen is led through the

the flask is sufliciently long t o reach just above the surface of the liquid, 80 as t o ensure the complete expulsion ofthe air by the gas. When the vessel is completely full of hydrogen, the ends of the tubes (A) and (B) are closed during the actual transmimion of the gas, either by mrew-clamps or by glass rods, and the whole is phced in the direct sunlight, wlien the platilium is quickly: reduced t o the metallic state, and the solution ultimately becomes perfectly

tube (A), and the end of the exit tube (B), within + 4-

2 P 2

Publ

ishe

d on

01

Janu

ary

1868

. Dow

nloa

ded

by S

tate

Uni

vers

ity o

f N

ew Y

ork

at S

tony

Bro

ok o

n 26

/10/

2014

02:

44:1

3. View Article Online

520 TRORPE’S ANALYSIS OF THE ASHES

coloiurless. The process of reduction may, if necessary, be faci- litated by heating the solution on a vater-bat8h before the trans- mission of the gas. If the capacity of bhe A ask is small, it may be requisite t o re-fill it once or twice with hydrogen, t o emure the complete reduction of the platinum; i t is then desirable t o displace the remaining-gas by a rapid current of carbonic wid ; otherwise an explosion might possibly occur, particularly if the contents of the flask are warm, owing t o the surface action of the finely divided metal on a mixture of air and hydrogen. The clear solution was then filtered from the finely divided platinum, and after concentration the magnesia was precipitated in the uaual way by sodium phosphate and ammonia, and its weight deducted from that of the mixed chlorides. This method is recommended to be used in all accurate separatioiis of the alkalies from inag- nesia; it moreover offers a rapid and eaay mode of recovei+q?,- the excess of platinum used in the determination of potash.

(A.) Analysis of the A s h of the Root$.

413.4 grms. of the roofs, freed as far as possible fioiii adhering sand and Boil, left on burning 5.686 grins. of a&. Amount taken for analysis, 4.9315 grms. After treatment with car- bonic acid, the insoluble portion weighed 5.081 G grins., the solution of the soluble portion, 66.2125 grms.

I. Composition of the Insohble Portion.

grms. grms. 1.1431 gave Silica ...................... 0*0710

Magncgium PJrophosphate , , . , 0*173E Ferric oxide ................ 0.01 00 Lime ...................... 0.5021 Magnesium pyrophosphate * . , , 0.0199

0.5868 lost on treatment with dilute acid , . 0’2289 1.2273 ,, Do. do. . . . . 0‘0214

Tot,al weight of Calcium Siilphate

Amount in total insoluble portion,

grms. Silica ........ 0.31554

Ferric oxide . . 0’01444 Lime ........ 2.23145 Phosphoric acid 0.05655

D @.. 0.05668 Carbonic acid . . 1.98230

Xagnesia ...... 0-2’7787

................ OfJOBO

11. Composition of thc Soln ble Portion. Amount in total soluble

portion. grms. grms. grms. 10.1446 solution gave Barium sulpliate . . , , , . 0.0751 SoIphuric acid. . 0*16827 9.6667 . . . . Silver cliloride.. ...... 0.0191 Chlorine . . . . . . 0‘03236

10.3215 . . . . Mixed chlorides ...... 0’1290 Potash ........ 0.21331 Plztinum-salt ........ 0.1968 Soda, ......... 0.23466

9*2150 ,, reqnirc-d 11 C . C . C;O,H-sol. (I 1 i: G*C@22) Carbouic w i t 1 , , 0.17332

Publ

ishe

d on

01

Janu

ary

1868

. Dow

nloa

ded

by S

tate

Uni

vers

ity o

f N

ew Y

ork

at S

tony

Bro

ok o

n 26

/10/

2014

02:

44:1

3. View Article Online

52 1 OF A DISEASED ORANGE TREE.

( H . ) iicdysis of the l t s h of the l % > ~ ~ ~ .

JIacle by Hwr Giitscliow. 122.5 grma. of' tlie wood left 4.00 grim. of ash. rlniouiit taken for analysis, 2.9551 e m s . After treatment with carbonic acid, the iiisoluble portion weighed 2.6687 grms. : the solution of the soluble portion weighed 40.5186 grma.

I. Composition of the Insoluble Portion.

grms. grms. 0.8945 gave Magnesium pyrophosphate . , . , , 0.0955

Do. do. ...... G-0175 ,, Lime.. ...................... 0.4465

0.471 9 lost on treatment with acid.. ........ 0.1983

IT. Composition of the Soluble Portion.

grms. grms. 8.4638 solution gave Silver chloride ........ 0.0652 8'1861 ,, ,, Barium sulphate ...... OwO420

8.1500 ,, ,, Mixed chlorides ........ 0.0882 '1.7'051 ,, ,, Magnesium pyrophosphate 0'0050

Platinum salt .......... 0.2204 Mnpefii urn pyrophosphate 0'0 03 0

8.0736 ,, required l U . 7 C.C. S04H2 solu- tion (10.7 x 0'0011)

Amount in total insoluble portion.

grmfi. Magnesia.. .... 0.10269 Phosphoric acid 0-03340 Lime ........ 1.33210 Carbonic acid . . 1.08750

Amount in total solution. grms.

Chlorine . . , . . , 0.06542 Sulphuric acid.. 0.07147 Phosphoric acid. 0.01684

Potash ........ 0.20225 Soda.. ........ 0.06081 Carbonic acid . . 0'05916

(C.) Analysis of the i l s h of the Branches.

Made by Herr H. Kno p f. Amount taken for analysis, 5.01 15 grms. After treatment with carbonic acict, the insoluble por- tion weighed 4.8286 grms ; the so1utio.u of the soluble portion, 47.7822 grms.

I. Composition of the Insoluble Portion. Amount in total insoluble

portion. grins. grms. grme.

Magnesium pyrophosphate , , . . , . 0*0622 Phosphoric acid. 0.14004 Ferric oxide. ................. 0.0042 Ferric oxide 0*01460 Lime ........................ 0.8837 Lime ........ 2.38950 IIagiicaium yj-rophoaphak, ..... 0.0992 Magnesia ...... 0'1 2498

0-j.52.j lost on trcatniciit with acid .......... 0'2104 Carbmi:: acid .. 1.63340

1.3815 gave Silica.. ...................... 0.0260 Silica ........ 0.09037

Publ

ishe

d on

01

Janu

ary

1868

. Dow

nloa

ded

by S

tate

Uni

vers

ity o

f N

ew Y

ork

at S

tony

Bro

ok o

n 26

/10/

2014

02:

44:1

3. View Article Online

522 THORPE'S ANALYSIS OF THE ASHES

11. Composit'ion of the Soluble Portion.

grms. grms. grms.

solution. Carbonic aoid . . 8*0476 6.9950 ,, gave Mired chlorides . . . . . , 0.0293 8oda.. , . . . . . . . 0.02186

Platinum salt . . . . . . . . 0.0770 Potash . , . . . . , . 0.10110 6.9592 ,, Barium sulphate . . . . 0.0050 Sulphuric acid., 0.0116 7.0647 ., ,, Silver chloride , . . . . . , 0'0016 Chlorine , , , , , 0*0027

11*0066 sdution required 5 C.C. normal HC1

(D.) Analysis of t l e A s 7 ~ of the FT*uit.

Amount taken for analysis, 5.5482 grms. After treatment with carbonic acid, the weight of the insoluble portion WRY

2.2948 grms.: that of the solution of the soluble portion was 59.9210 gnus.

I. Compoaition of the Insoluble Portion. Amaunt in total insoluble

portion. F grms. g.IUlS. 0.9339 gave Silica.. . . . a ,. . . a . . . . . . . .. . 0,0085 Silica . . . . . . . , 0-02062

Magnesium pvophospbate . . . . . . 9.2970 Phosphoric acid, 0,46085 Ferric oxide.. . . . . . . . . . . . . . , 0.0023 Ferric oxide.. . . 0.00560 Lime .. . . . . . . . .. . . . . . . I . . . . 0.3834 Lime.. , . , , . . . , 0,94191 Magnesium pyrophosphate . . . . . 0,2021 Nagnesia . . , , , , 0.17667

0.5149 lost on treatment with dilute HCl . . . . 0.1 045 Carbonic acid . . 0.45978 Total weight of calcium sulphate . , . . . . . . , . , , . , 0*02930

11. Composition of the SQluble Portion.

g m 0 . grms. 6.0420 solution gave Barium sulphate.. . , . . . . 9.0395 5.1163 ,, ,, Silver chloride,. . . . . . . . . 0.0304 9.8770 ,, ), Magnesium pyrophosphate 0.0059 7-9500 ), ), Mixed chlorides.. .. . . .. 0.4497

Platinum salt . . , . . . , . . . 1.4246 Magnesium pyrophosphate 0-001 7

6.2297 ,, required 42.1 C.C. S04Hz soln- tion (42*1 x 0'0022).

Amount in total solution. grme.

Sulphuric acid.. 0.13442 Chlorine . . . . . . 0.08805 Phosphoric acid. 0-02305 Potash . . . . . . I . 2006950 Soda.. . . . . . . . . 0*05800

Carbonic acid . . 0.89086

Reducing all these results to percentages, after dedncting the amount o f carbonic acid, the composition of the ash of the root? s k a a , h w h e s , and fruit irJ found to be aa follows :-

Publ

ishe

d on

01

Janu

ary

1868

. Dow

nloa

ded

by S

tate

Uni

vers

ity o

f N

ew Y

ork

at S

tony

Bro

ok o

n 26

/10/

2014

02:

44:1

3. View Article Online

OF h DISEASED ORANGE TREE,

Seed.

523

Fruit (Richard-

son).

Potash.. . . .. .. .. .. .. .. .. . . Soda.. . . . . . . . . . . . . . . . . . . . . Lime .. . . .. . . . . .. . . . , . . .. Magnesia . . . . . . . . . . . . . . . . Ferric oxide . . . . . . . . . . . . . . Chlorine . . . . . . . . . . . . . . . . . . Phosphoric acid.. . . . . . . . . , . Sulphuric acid . . . . . . . . . . . Silicic acid . . . . . . . . , . . . . . . . Calcium sulphate . . . . . . . . . ,

Stem.

Root.

Leaves.

6 '74 6 '50

61 '82 7 '70 1 '23 0 '90 1 -57 4 '66 8 9'4 0 *14

l o @ -00 --

3.30

40.28 0.92

18.97 3.7'4 0.80 0.82

23-24 5.10 1.13

100~00

Stem.

---- 38.72

'7.64 22-99

6.55 1.7'42

trace 14-17 2.95 5.25

100~00 ----

10 -79 3 -22

'70.67 5 *92

3 *48 2 *66 3 -26

--

Lime . . . . . . . . . . . . . . . . Magnesia . . , . . . . . . . . . Ferric oxide.. . . .. . . . . Sodium chloride . . . . . . Phosphoric acid . . . . . . Sulpliuric acid. . . . . . . . Silicic acid . . . . . . , . , .

Branches.

49.89 6-91 1.02 1-18

13.47' 5-78 1.75

3 -49 0 -75

82 '49 4 *31 0 '51 0 '09 4 '83 0.40 3 '13 .. --

1 0 0 ~ 0 0 1 l o @ *oo

Fruit.

5 1 *64 1'45 23 -50 4 -41 0 .14 2 -19

12 -07 3 -35 0 *52 0 '73

100 so0

For the sake of comparisoii, I here append the results of ;I,

similar series of analyses made some years ago by Messrs. Rowney and How, of ashes obt.ained from perfectly healthy trees grown in the island of St. Michael.* In the last colunz~i I also add an analysis of the entire fruit by Dr. Richardson.? Tlie results: of these analyses are here represented in per- centages, after deduction of the unessential constituents, i.~., carbonic acid, sand, and charcoal.

Root.

Amount of ash left by 4.48 100 pts. m . . . . I . * * . } 1 I- -- 2-74 1 13-73 --

11.69 3'07

55.13 6-34 0'57 0.25

17.09 4.64 1.22

18.51 1.68

56.38 5-72 0.52 6.66 3.27 4.43 4-83

Fruit.

3.94

36.42 13-42 24.52 8.0 6 0*46

11.07 3.74 0.44

--

3.87

100'00 I 10oao0 1 100~00

It will at once be noticed, on instituting the compariscn, that the coiiiposition of the ashes of the healthy tree differs widely

* Reports, &c., Royal College of Chemistry, 1847, Journal of Chemical Society. f Ann. Ch. Pharm., lxvii, 3'17, 1848.

Ferric phosphat,e,

Publ

ishe

d on

01

Janu

ary

1868

. Dow

nloa

ded

by S

tate

Uni

vers

ity o

f N

ew Y

ork

at S

tony

Bro

ok o

n 26

/10/

2014

02:

44:1

3. View Article Online

from that of the diseased specinlens. The waut of analogy is inore particularly seen in the undue proportion of limc, and the comparative lack of phosphoric acid in all parts of tho unlieitlthy tree, with the exception of the fruit; but the concentration of potash in the latter is remarkablc. TVhether, however, these deviations may in any way be connected Tvitli tho source of the disease, or are themselves its results, reinains still t o be demonstrated. Hitherto the culture of the orangc has no~v11er.e been carried t o a greater degree of perfection than in the Balearic Ides; but the yield of fruit seems t o have been forced by excessive manuring t o a most unnatural extent ; and pro- bably in this ’injudicious overworking of the trees inay be found the cause of their sickening.

Heidelberg, September, 186%

Publ

ishe

d on

01

Janu

ary

1868

. Dow

nloa

ded

by S

tate

Uni

vers

ity o

f N

ew Y

ork

at S

tony

Bro

ok o

n 26

/10/

2014

02:

44:1

3. View Article Online