Obrazy na stronie
[ocr errors]


Development of the Chemical Arts.


Iodine.-The rapid extension in the demand of the THE CHEMICAL NEW S. splendid violet, blue, and green coal-tar colours, which

are prepared by means of the iodides of the hydrocarbons

has in the last few years occasioned a notable increase in VOL. XXXIV. No. 885.

the consumption of iodine. The production, from very simple reasons, could not keep pace with the growing consumption, which of course led to a considerable in crease in the commercial value of a body relatively of

such rare occurrence in nature. Its price has been REPORT

further increased by the circumstance that the seaweed

ashes of England and France (Kelp, Varec) have become DEVELOPMENT OF THE CHEMICAL ARTS less remunerative to the producers. Formerly these weed

ashes served to supply a considerable part of the demand DURING THE LAST TEN YEARS.*

for the salts of potash, but since the utilisation of the By Dr. A. W. HOFMANN.

well-known“ Abraum salts" of Stassfurt the extraction (Continued from p. 188.)

of potash salts from seaweed ashes has become so unremunerative that the loss in the returns of the kelp trade

has to be balanced by a rise in the price of the iodine.* Chlorine, Bromine, Iodine, and Fluorine.

The hope of a fall in the commercial value of iodine in By Dr. E. Mylius, of Ludwigshafen.

consequence of its extraction from the mother-liquors of
The arrangements for the ventilation of the bromine i nitrate of soda has not been fulfilled. The production of
works are peculiarly interesting. Th critical moment is iodine from this source has increased but little, and some
when the manganese liquid is run out of the stone tanks, nitre refineries, which had commenced the utilisation of
since it throws off vapours of chlorine and bromine in the iodiserous mother-liquors, have again abandoned the
abundance. Yet the operation is performed without the attempt. On the other hand, in tinctorial industry at-
least inconvenience to the workman. Along the series of tempts have been made to dispense with the use of iodine.
stills there runs a channel of brickwork, through which a. Although the attempt to employ bromine in place of
powerful current of air is drawn by the great chimney of iodine (see “ Bromine”) has failed, other methods have
the works in a direction opposite to that in which the recently been discuvered for producing the most magnifi-
liquid runs off. The channel is situated so that the vent cent violet, blue, and green tar colours without the aid of
holes of the stills open into it. In front of every still iodine. Nevertheless the price has not been essentially
there is introduced in the roof of the channel a damper reduced since the methods for preparing the dyes without
which is opened when the plug of the vent hole is about iodine have not by any means been adopted in all
to be knocked out. The draught is so powerful that the establishments.
workmen are not in the slightest degree incommoded by the In addition to the tinctorial arts iodine is employed in
vapours evolved from the stream of solution of manganese. scientific chemistry, where its importance is incalculable
The workshops smell distinctly of bromine, but the odour and also in photography and in medicine.
is far fainter than that which is experienced in our

(To be continued).
scientific laboratories during the bronation of organic

As has been already remarked, crude bromine always
contains a little chlorine, even when, according to the

ON SOME EFFECTS PRODUCED BY THE Stasssurt practice, the Woolf bottle is allowed to become ADDITION OF SULPHATE OF ALUMINA IN slightly warm towards the end of the operation, so as to

drive the volatile chloride of bromine over into the iron-
turnings. A rectification is therefore requisite. This

takes place in glass retorts containing about 15 litres, the
nec ks being cemented into receivers bedded in cold water. In your review of a recent publication, “ Causeries Scien-
Each retort is set in a separate sand-bath, so that if one | tifique" (Chem. News, vol. xxxiv., p. 69), the reader's
happens to burst-and such misfortunes cannot be attention is directed to the following paragraph :-“Sul-
avoided—the injury may be limited as much as possible, phate of alumina, on which so much dependence has been
Only a slight aqueous fraction contains chlorine; it is placed, certainly clarifies the sewage. The gelatinous
withdrawn and returned to the stone stills. The rectifica- alumina agglutinates the solid substances, but the dissolved
tion lasts about twenty-four hours. The atmosphere in matters, mineral and organic, are nowise retained.” The
the rectifying house is more offensive than that in the last sentence, which is a very faithful translation from the
still-houses, since all currents of air must be carefully original, contains a statement which is neither new nor
avoided. The workmen, however, require to enter this true, and the language employed reminds one of the
room from time to time. Moreover there are especial great Dr. Johnson's way of disposing of the swallows in
arrangements which render it possible to decant the

“ Numbers of them,” says the learned Doctor, bromine both out of the Woolf's bottles into the retorts, * conglobulate together, and precipitate themselves into the and from the receivers into the vessels used for transport water." That the application of sulphate of alumina to without any annoyance from the vapours abundantly the sewage removes nothing but the suspended matter has evolved during these operations. The decantation is per- been asserted over and over again by persons who, from formed in wooden chests, through which a violent current their position, would have been supposed to have known of air is drawn by the great chimney. The workmen better; and perhaps it would not be amiss, now that the soon acquire such dexterity and accuracy in these manipulations that they are content to cover the respiratory * According to a letter from Mr. E. Stanford, of Glasgow, to-Prof. organs with a wet cloth, and disdain to make use of the A. W. Hofmann, a ton of chloride of potassium in 1863 cost £21 135.; ventilating arrangements placed at their disposal.

in the ten following years on an average £15 155.; and is now worth (At Stassfurt bromine is sent off in strong glass bottles only.p 10s. The price of iodine has risen in a corresponding degree;

in 1863 an ounce of iodine cost 410.; on the average of the following holding 2'5 kilos. The well-ground stoppers are sealed ten years 7d. ; whilst it is now worth 1s. 3d. per ounce. with shellac, luted with clay, and tied up with parchment + According to private communications from M. E. Schering the paper. Four or twelve such bottles are packed in a chest. production of iodine from the mother-liquors of soda salt petre is again

A Peruvian nitre refinery, which separates the -A. W. H.)

iodine as cuprous iodide by means of bisulphite of soda and sulphate

of copper, produced, in 1873, 15,000 kilos. cuprous iodide, and is about * " Berichte über die Entwickelung der Chemischen Industr'e to increase its production to 50,000 kilos., corresponding to 30,000 kilos. Während des Letzten Jahrzehends."

1 of iodine.


Per cent.


Analysis of an Iron Deposit.


, public attention is turned to the sewage question, to re- the deposit was allowed to settle, the water decanted off, capitulate some of the substances carried down by alumina. and the residual slimy matter dried at 100° C. before And, first, the phosphoric acid is removed from the sewage, analysis. and by its removal the effluent water is found to be less Examined under the microscope the deposit proves to liable to putrefaction, while the manure derived from the consist almost entirely of the Conservoid Algæ, Didymo sewage must be to some extent improved, although I am helix ferruginea, together with a small amount of amoraware the value of phosphate of alumina as a manure has phous ferric precipitate. been called in question. Secondly, albuminoid substances are carried down by

Organic matter and water.. 50*74 the alumina. I think this is proved by the general be

Ferric oxide ..

43'29 haviour of bodies of this nature with alumina, and also

Ferrous oxide

3:58 by the percentage of nitrogen found in the precipitated


0:51 mud, which is higher than would be produced by the sus.

Magnesia pended matter alone. The albuminoids are found to un

Sulphuric anhydride

I'29 dergo rapid decomposition and to give forth offensive

Phosphoric anhydride..

0'18 odours, and their removal tends to keep the effluent water


0'15 sweet.

Soluble silica

0 31 Thirdly, the fatty acids of soap dissolved in the sewage


0.65 are carried down by the alumina--a point which, I think, has been hitherto somewhat overlooked. It is true that

100 80 there is some loss in the subsequent drying of the mud, Laboratory, Wallasey Ore Yard, bot a considerable portion of these fatty bodies is obsti

Birkenhead. sately retained by the alumina, as may be proved by experiment. I am inclined to think that the beneficial effects produced by the sewage manure on the land is in a

COUNTRY LABORATORY APPARATUS. great measure due to the large quantity of fatty matters No.I. Flower-Pot Gas FURNACE, CRUCIBLE Jacket, &c. precipitated by the alumina. Farmers have assured me No. II. Rough AND Ready METHOD OF ESTIMATING that they found the manure of considerable value, and I

VOLATILE Matter AND COKE IN COAL. think the effect of the fatty matters on the soil has not up to this moment been sufficiently considered.

By EDWARD T. HARDMAN, F.C.S., An enterprising firm proposed some time ago to manu

H.M. Geological Survey, Ireland. facture artificial butter from the Thames mud, and I have myself made a very fair cake of soap from the fatty acids No. I. The following short description of an extremely extracted from the sewage mud. The association of effective, cheap, and cleanly substitute for crucible jackets, ideas, however, is not agreeable, although I do not think &c., may be useful, especially to those who, like myself, the most fastidious person would object to burn a candle have occasion to shift their quarters often, and are which had been derived from the sewage.

obliged to work with a necessarily limited laboratory In some of the Towns of Yorkshire-Leeds, for in- accommodation. stance-I have been told that a large quantity of soap is The ordinary crucible jacket being made of sheet-iron found in the sewage, not because the Yorkshire folk are has in reality but one use--to protect the flame from more frequent in their ablutions than other people, but currents of air. The small concentration of heat which from the fact that soap is extensively used in the manu- it affords may be regarded as nearly nil, since, from the facturing processes, and it is possible that some portion nature of the material and its thinness, radiation takes might be recovered from the sewage. If so, the question place very freely. of “How are you off for soap ?" when addressed to cor. Another drawback it has, is that it soon becomes rusty porations and local boards, would assume a new signifi. or coated with scale. It is not only dirty to handle therecance, as its recovery from the sewage would form some fore, but also presents the inconvenience of dropping set-off to the expense of purification.

some of its scale into the crucible if not carefully mani. Wellfield Villa, Turnchapel, Plymouth,

pulated. Then it is an awkward thing to pack, taking up October 17, 1876.

a good deal of space, rusting everything it comes in contact with, and behaving generally in a disagreeable

manner; while, as it is not to be obtained in country ANALYSIS OF AN IRON DEPOSIT. towns, it may not be left behind.

Now an ordinary earthenware flower-pot answers the By G. PATERSON.

purpose in every respect. It is the proper shape, and

being made of a non-conducting material it in a great The deposit of which an analysis is given below is from measure prevents loss of heat from the burner. It is exthe surface of the Lochar Moss, a very extensive peat tremely cleanly to use, and last but not least, it can be moss now in part under cultivation in the south of Scot. procured in every town or village at the small cost of one land, bordering on the Solway Firth. It is found in large halspenny or so; so that there is no necessity to cumber quantity in the open ditches and drains; in the latter it is oneself with it when moving. formed in such considerable quantity that the tiles in time The bottom of the flower-pot has a circular hole. This become entirely choked up, so that they have to be raised serves for the introduction of the Bunsen burner. As the and cleaned. In the ditches it forms, below the running supply of air would be insufficient otherwise it will be water, a layer of thick red-brown slime, often 10 to 12 necessary to enlarge the opening. This can be easily inches in depth; and as these ditches have to be cleaned done with a knife, and I find it best to cut the aperture out at least once in the twelve months, and sometimes nearly in the form of a cross, and not too large. One or even more frequently, the amount of the deposit—which, two trials will give the happy medium. A current of air by the way, is commonly known in the district as “iron 18 then obtained which not only steadies the fame, but ore”--thrown up on the banks in course of time is very acts in some degree as a blast. The flower-pot may be large. Perfeâly clear water taken as it runs from the supported in the ring of a retort stand in the usual way. drains reacts strongly for proto-salts of iron, becomes The chimney is a second flower-pot inverted. To support cloudy after standing a few hours, and deposits a red it the handiest way will be to make three S hooks of stout brown sediment.

wire, and having passed the narrow end of the pot The sample taken for analysis was collected from an upward through the ring, fix the rim within the hooks open drain, and was quite free from any foreign matter ; caught on the ring, as in fig. 1.

Nov. 10, 1876.
Country Laboratory Apparatus.

199 It will be found convenient to devote a small retort whole is exposed to strong heat in the furnace for an hour stand permanently to the purpose. The whole arrange- or two, when the volatile matter is driven off. After ment is shown in fig. 2.

cooling the difference of weight against that determined This will be very handy, as the upper part can be raised before ignition gives the volatile matter. Having occasion to any desired height, regulating the heat and draught; or to determine the volatile matter of a coal, and not having can be shifted from side to side, whenever it is desirable at hand the elaborate arrangements referred to above, I to inspect the progress of the operation going on.

bethought me of the schoolboy's method of manufacturing The apparatus acts admirably as a small gas furnace coal-gas. The retort he uses is a common clay tobacco for crucible operations, such as the fusion of silicates with pipe. A piece of coal is put in, the top is luted with clay, carbonate of soda-as in the analyses of rocks ; while for and the pipe is inserted in the fire-grate with the stem simple ignition of precipitates it renders the flame of a projecting. Presently a dense smoke issues from it, and common glass spirit-lamp most effective. The size of the a match being applied a veritable gas light-but not flower-pot required will, of course, depend on that of the “ 16-candle”-results. On opening the luting a piece of crucible and of the burner used. I find the smallest size, coke is found in the pipe. I suppose most of us have 31 inches high and about 3 inches diameter at top performed this experiment. It is obvious that it is only (internal), most generally useful.

necessary to weigh the pipe and contents before and after The support for the crucible may be either a triangle of the operation, and we have the volatile matter and coke wire covered with pipe shank, the end of the wire being determined. bent upwards and formed into hooks so as to hang on the The larger the pipe the better. Those I have used hold edge of the flower-pot (fig. 3), or three pipe-covered wires about 100 grains of coal broken small but not powdered. suspended in the position of the ribs of a crucible jacket. The pipe is weighed, then filled with the coal and weighed The former is necessary for small crucibles.

again to obtain weight of coal. Then inside the top is The flower-pot also makes an excellent lamp screen, fitted a circular piece of writing-paper, the use of which for steadying and concentrating the flame under evaporat- is to prevent any of the luting getting down among the ing basins, &c.; of course a sufficient interval must be coal, where it could not be removed, and would falsify the kept between the pot and the basin, else the light will be last weighing. The top is luted with moist fireclay, or extinguished.

with the cement used for luting the covers of gas retorts,

[merged small][ocr errors][ocr errors][merged small][merged small]

A small flower-pot with wire gauze tied over the top is / and the pipe, being placed in a co.ninon coal fire or in a a very effective low temperature lamp when the gas is | gas furnace-thai described above (No. I.) answers very lighted below the gauze." If the gas is lighted above the well--from ten to twenty minutes completes the operation. gauze we have a capital argand lamp giving a large clear When cool the luting is carefully taken off and the blue flame. In the latter case a common burner can be charred paper removed. The pipe and contents being then used, a consideration when Bunsen's are all temporarily weighed, the loss gives the volatile matter, the same weighoccupied or not available.

ing, of course, determining the coke. If a very exact After a time the pots become cracked from the heat, determination is required, a quantity of the coal may be but as they are easily replaced this does not matter, and broken small, well mixed together, and four pipes filled as even when cracked they will often hold out for a consider. above. They can all be ignited together in a fire, and able time. Fireclay flower-pots made rather thick would, weighed very quickly. The results will be found to agree however, afford a really good cheap and portable furnace. very closely.

It has just occurred to me that by placing the power- The figures thus obtained do not differ from those pot inside another just large enough to encase it, loss of given by the same coal assayed on the laboratory plan to heat by radiation would be effectually checked.

a greater amount than will be found to occur between two No. II. The usual method of estimating the volatile experiments made on the same coal in the latter way. matter in coals implies a laboratory on rather an exten- And the tobacco pipe process has the great advantage of sive scale. A furnace with a good draught is required. The being very expeditiously performed--the whole experiment coal is placed in a large porcelain crucible, which is then including weighings not occupying more than thirty put into a Hessian crucible, and covered with powdered minutes—and with very simple apparatus. charcoal to exclude air. The cover being then put on, the Kilkenny, October 9, 1876.


Nov. 10, 1876.

200 Action of Different Fatty Oils upon Metallic Copper. ON THE ACTION OF DIFFERENT FATTY OILS UPON METALLIC


(Continued from p. 177.)



(Commenced October 1, 1875. Examined August 9, 1876.)

Name of Oil.

Appearance of oil when examined.

Appearance of strip of copper.

1 elative amounts

i copper con tained in solution

in the oil. of

Relative amounis
of the copper salt
dissolved by water,

Relative amounts of acidity given

to water.


1. Mesina Olive Oil. Yellowish colour and limpid. Thickly coated with salt of Trace. Trace. Trace.

copper; green incrusta

tion. 2. Olive Oil, Ditto.


Trace. . Trace. Trace. 3. Rape Oil.

The oil is of a brownish- The slip ofcopper is covered Trace. Trace. Trace. yellow colour.

with a slight dark coloured

deposit. 4. Refined Rape Oil. The colour has changed to a The slip is quite bright. Very large. Large. Rather deep green.

large. 5. Cotton Seed Oil. The oil has acquired a very The plate or slip is covered Very small. Trace. Absent.

slight greenish hue, and has all over with thin patches
formed a ring of icicle forms of green copper salt and
all round the glass at the dark coloured deposit,
surface of the oil; these mixed with tufts of solid
forms are of coagulated fatty matter, which has

also deposited on the
copper which lies at the

bottom of the oil.
6. Pale Cotlon Seed This has changed in every The copper slip is covered Small.


Very small

respect exactly like 5, with slightly with a dark de-
the exception that the icicle posit.

forms are not so thick. 7. Linseed Oil.

A tough skin covers the sur- The copper slip appears Very large. Very large. Large.

face of the oil, which has quite bright.

deep green

colour. 8. Oil of Almonds. The oil has acquired a slight The slip is covered with a Rather Moderate. Small, greenish hue.

very slight dark coloured large.

deposit. 9. Sperm Oil. The oil is of a dark brownish The slip of copper is quite Extremely Very large. Large. colour.


large. 10. Raw Cod-liver Oil. The oil has become as thick Ditto.

Large. Large. Large. as jelly, and is of a dark

amber colour. II. Pale Seal Oil. The oil has become of a thick Ditto.

Moderate. Small. Small. syrupy consistency, of the same colour as 10, but

lighter. 12. Seal Oil. The oil has the same con


Moderate. Small. Small. sistency as II, but is

slightly darker in colour. 13. Lard Oil.

The oil has become slightly The slip is covered with a Large. Small. Trace. greenish in colour.

greenish-black deposit. 14. Foreign Neatsfoot The oil is of a yellowish The slip of copper is thickly Trace. Absent.

Rather Oil, colour ; white flakes and covered with a green de

large. pellets of solid fats have posit of copper salt. settled to the bottom, and fill it to about one-third

the volume of the oil. 15. Tallow Oil.

Has become solid, with a The slip is covered with a Absent. Absent. Rather honeycombed appearance, green deposit of copper

large. produced by irregular, cell- salt. like deposits of solid fat

mixed with the liquid oil. 16. Neatsfoot Oil. A white deposit of solid fat The slip is covered with a Absent. Absent. Very large.

has settled to the bottom; thick green deposit.
the supernatant oil is almost
colourless and quite limpid.

* Read before the British Association, Glasgow Meeting Section B.).

[blocks in formation]

Relative amounts

of copper con-
tained in solution

in the oil.

Relative amounts
of the copper salt
dissolved by water.

Relative amounts of acidity given

to water.


17. Cotton-seed Oil. The oil is almost colourless, A dark coloured deposit Small. Trace. Large.

but has a greenish hue ; a covers the surface of the
ring of coagulated, oil-like

icicles are attached to the
glass at the surface of the

oil. 18. Palm Oil.

No change appears to have The slip is covered with a Very small. Very small. Large.
taken place in the oil. bright green deposit of

copper salt ; at
parts, however, the cop-

per appears quite bright. 19. Whale Oil.

The surface of the oil is The copper slip is quite Trace. Trace. Large.

covered with a thick, hard bright.
skin, but the oil is quite

fluid underneath.
20. Cod Oil.
The oil is of a dark amber Ditto.

Very small. Trace. Very large. colour, and is covered with a soft, elastic skin, and has

the consistency of jelly. 21. Shark Oil. The oil is of a reddish brown Ditto.

Moderate. Trace. Large. colour and quite liquid. 22. Newfoundland Cod The oil has a syrupy consis- Ditto.

- Very large. Small. Very large. Oil.

tency and dark amber colour. 23. Common Seal Oil. The oil has a syrupy consis. The slip of copper is quite Very large. Small. Very large

tency and a dark bright bright.

amber colour. 24. East Indian Fish The oil has a light yellowish- Ditto.

Trace. Absent. Very large. Oil.

brown colour. 25. Heavy Mineral Oil. The oil has a dark reddish- The copper slip is covered Absent. Absent. Absent. yellow appearance.

with a very slight greyish

deposit. 26. Mineral Oil. The oil has a brownish-red The slip is covered with a Absent. Absent. Absent. colour.

slight dark grey deposit.



At the Chemical Works at Aalborg, in Jutland, Denmark,

(Concluded from page 193). where about 30 tons of alkali are made per week by the ammonia process, Mr. Thowald Schmidt, the Director of the Manufactory, proposes to work, in conjunction with ! HAVE stated at the beginning of this article that the this process, a method devised by himself of treating sea- failure with sulphuric acid induced me to look for another weed so as to obtain iodine, potash salts, and other test and led me to the separation of the products of oxida. marketable products therefrom. In Denmark a very

tion into crystals and powder. It was natural, therefore, heavy duty is levied on the importation of common salt, that I should apply the sulphuric acid not only to the whilst enormous quantities of seaweed rich in iodine and mixture but also to the two separate products, and the potash can be obtained at small cost in the neighbourhood results thus obtained point with almost absolute certainty of the works. Mr. Schmidt's process is as follows:

to the conclusion that the powder is practically useless, After the seaweed is dried and burnt a concentrated solu. and is, in fact, no anthraquinone at all. tion of the ash is made and added to the liquor containing

I have tried the usual sulphuric acid and also fuming chlorides of sodium and calcium, left after the ammonia

or Nordhausen acid, the use of which naturally suggested has been recovered in the ammonia-soda process by boil. itself from its application in the alızarıne manufacture. ing with lime. The sulphates of potash, soda, and The results obtained do not sensibly vary, but I have magnesia contained in the ash of the seaweed are thereby adopted the last acid as the strongest and most active, decomposed, and hydrated sulphate of lime and hydrated and I may state that in speaking of sulphuric acid I magnesia are precipitated in a form which may be avail- always mean fuming or Nordhausen acid. able for paper-making as "pearl-hardening." The last

The samples treated, a small proportion of which only traces of sulphates are got rid of by adding a small quan

are given in the first table, are so different that it is tity of solution of chloride of barium. To the clear solu- necessary to record the separate results; but I am anxious tion nitrate of lead is now added until all the iodine is to condense the matter as much as possible, and I have precipitated as iodide of lead, which is then separated by therefore in the following table reduced to one-half the filtration and treated for the production of iodine or number of experiments of the first table. The treatment iodides. After filtration the liquid is boiled, nitrate of with acid was carried out in the following manner :soda is added to convert the chloride of potassium present The products of oxidation were for ten minutes heated into nitrate of potash. The latter is separated by crystal- in a small porcelain basin or in a large watch-glass with lisation. There remains a solution of common salt con- ten times their weight of acid at a temperature not extaining traces of ammonia from the previous soda operation ceeding 110° C.; they were then allowed to stand for and a trace of chloride of potassium. This solution is twelve hours, largely diluted with water and brought on a again treated by the ordinary ammonia-soda process for double filter, well washed, dried, and weighed. In the he production of bicarbonate of soda and white alkali. following table the first line of cach number gives the

« PoprzedniaDalej »