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CHEMICAL News,

Sept. 1, 1866,

On a Process of Fractional Condensation, 8;c.

97

SCIENTIFIC AND ANALYTICAL

Figs. 1 and 2,$$ the temperature of which is regulated by CHEMISTRY.

means of a separate lamp, b, Fig. 2, or by a safety fur. nace, p, as shown in Fig. 1. The bath may be of oil or

water, or of metal for very high temperatures, as the On a Process of Fractional Condensation, applicable to case may require, and is furnished with a thermometer, t.

the Separation of Bodies having small Differences That this hath may be equally adapted for the sepabetween their Boiling Prints, by C. M. WARREN. ration of liquids boiling below the common temperature, (Continued from page 86.)

an empty vessel, c, Fig. 1 and 2, is permanently secured of the New Process.— The chief distinctive feature in the interior of the bath by means of straps of metal of my process, as compared with the common one, con across the top to serve as a convenient receptacle for ice sists in this, that the operator has complete and easy or iced water, by means of which a low temperature control of the temperature of the vapours given off in may be steadily maintained. This interior vessel also distillation, and consequently can readily cool these serves a good purpose in economising time and fuel in vapours to the lowest limit of temperature which the heating the bath, as it diminishes the quantity of oil most volatile portion, under the circumstances, is able to required to cover the worm. It is made to extend to bear and retain its vaporous condition. It will be seen within about three inches of the bottom of the bath, and at a glance that, under these conditions, the operator has large enough to fill the greater part of the spice in the it in his power to secure in any case the very largest centre of the coil. The bath and interior vessel are both possible amount of condensation of the heavier from the made of sheet copper, with joints brazed so that they lighter vapours. The liquids resulting from the conden- will bear a high temperature. I generally use also sation of the less volatile portions of course fall back copper worms, especially in the earlier distillations, the into the retort, while the vapours of the more volatile quantities then operated up in being larger, as such parts continue to go forward to a cold condenser, descend worms are conveniently procured and not liable to break. ing in the opposite direction, from which the condensed In the larger sized apparatus, the tube of which the product falls into a special receiver. In this manner he worm is made measures ten feet in length and half an is able to obtain in each succes sive operation a series of inch in diameter. I have tried several lengths of worm products which shall contain the minimum quantity of and several diameters of tube, but not as yet with any the less volatile constituents which a single distillation special view of determining the precise proportions, in is capable of affording.

relation to the size of the retort, which would be best of the common process, on the contrary, nearly the adapted to the purpose. There appears, however, to be reverse of all this is true, the operator having no control nothing gained by increasing the length of the worm whatever, being forced to receive the vapours at the beyond what is required to reduce the temperature of temperature which they naturally acquire in passing the vapours to that of the bath I have in use three from the retort, and laden with such proportion of the sizes of apparatus. The largest has a copper worm jo less volatile bodies as may be carried forward with feet long and } inch Lore; the medium size, a worm them.11

5 feet long and 3 inch bore; and the smallest size, for In the new process, perfect control of the temperature very small quantities, a worm 1 foot 6 inches long and of the vapours is secured by simply conducting these 1 inch bore. Each of these has been found to answer vapours upward through a worm contained in a bath, aa, a good purpose. The distillation may be conducted in

a glass flask, or more conveniently in a glass retort of 11 The only apparatus of which I have any knowledge which can be regarded as bearing any an:dlogy to my own is that employed in

the form shown at d, Figs. 1 and 2. The body of this the rectification of alcoholic spirits on a manufacturing scale. In one retort, as appears in the figure, is of the form of the of the older forms of this apparatus, that of Solimani, to which my corresponding part of the common retort, but which, in use wore than a twelvem nth, the temperature of' a dephlegmator is place of a long neck, has only a short tubulure, e, in the kept within such limits as to give alcohol of any required strength side, for escape of the vapours, and another tubulure, more readily than by the common methods. The mode of construction of this apparatus is, however, only ariapted to manufacturing f, in the top, which contains the thermometer, and through purposes, and it could not be utilised in the more exact experiments

which the retort is charged. required in scientific research. Either on account of its complication,

In the larger apparatus the retort is connected with or some other cause, the apparatus of Solimani has, I believe, long eince been abandoned.

the lower end of the elevated worm by means of a glass Mansfield (Quarterly Journal of the Chemical Society, 1849, i. 264), tube of about the same diameter as the end of the worm. observing that "the boiling point of benzole is the same as that of One end of this tube enters the retort at the lateral cesses of rectification 'which are practised by distillers in the manu- tubulure through a perforated cork, and the other end is facture of alcoholic spirits are applicable to the separation of beuzole joined to the end of the worm either by being firmly tific treatise on coal tar, under the title of a Practical Mode of Pre-bound with a strip of cloth thickly covered with vul. paring Benzole," goes on to describe a process for that purpose, which canised caoutchouc-such as is found in commerce-or I believe he had previously patented. It appears that Mansfield did not employ this process in his research, but obtained his benzole, as by means of a perforated cork, which is made to fit the well as the other less volatile hydrocarbons, in the usual manner-by ends of both tubes as snugly as possible, and then simple distillation.

In the belief that no process of fractirning at all analogous to mine tightly pressed together upon the joint by means of an has ever been employed in scientific research, and that I am not in iron clamp, as shown at g, Fig. 2. This clamp is figured aby way directly indebted to any of the devices of my predecessors,

on a larger scale at E. As it is highly important that I have taken no special pains to consider these devices in much detail I may say, however, that I have found no record of any one's ever all joints in the apparatus should be perfectly tight, baving employed the oil bath and a separate fire to regulate a heated inasmuch as the least leakage, when continued a long condenser, this being the essential feature on which the superiority of my process is based, adapting it at once to both high and low ten

time, would cause in the aggregate a serious loss of peratures and for the most delicate work.

material, I would call special attention to the clamp The employment of bulbs above referred to as proposed by Wurtz; joint as the best which I have tried. Before falling nishes the same, or at most but slightly better, results thin a simple upon this device I had used exclusively the vulcanised retort, being no more than equivalent to increasing the height ot the caoutchouc joints, which were found to answer a good sides of the retort itself, without introducing any control over the accuracy of the results, the only advantage gaiued being that these $$ We owe these illustrations to the kindness of the author, who has results are obtained somewhat more quickly.

been good enough to forward them from America. VOL. XII. No. 300.-SEPTEMBER 1, 1865.

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purpose in most cases, except that they required too fumes which are given off in large quantity from such a frequent renewal. I have found the cloth covered with mass of heated oil, the top of the bath is tightly closed vulcanised caoutchouc preferable to the common caout with a sheet iron cover, from which a small funnel, A, chouc tubing. In the smaller sizes of apparatus I have Fig. 1, conducts these fumes to a chimney. the end of the worm itself project far enough from the In the larger apparatus, the vapours which succeed in bath to connect directly with the retort by means of a passing through the heated worm are conducted downperforated cork, without the use of an additional con- ward into a cooled worm contained in a bath of water, necting tube.

ii, Fig. 2, and the liquid product is collected in the reThe upper end, h, of the elevated worm is brought ceiver, k. The cold bath, iï, contains two condensing out through the side of the bath at a point about three worms - one for each apparatus—and is large enough to inches below the top, so that, when working with a low condense for both without the necessity of renewing the temperature of the bath, the worm may still be com- water. I have represented two apparatuses combined, pletely covered with oil, and also give sufficient space as it will be found more economical of time to operate above the worm for the expansion of the oil when higher with two at once. In the smaller apparatus for the temperatures are employed. To avoid contaminating table, a Liebig condenser may be conveniently substituted the atmosphere of the laboratory with the disagreeable for the cold worm, as shown in Fig. 1.

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For collecting liquids which boil below the common is enough smaller than the inside diameter of the upper temperature, when such are present, I attach a refrige- end of the tube, n, to leave room for a piece of caoutrator, B, Fig. 2, which is provided with two block tin chouc tube to be drawn over it and still admit of its condensing tubes—one for each apparatus. These are being inserted in the end of the tube, n; the flexible bent in a zigzag form, and attached to the inner sides of tube is drawn on far enough to prevent the drops which the refrigerator. The lower ends of the tubes extend form on the end of the worm from coming in contact through the end of the refrigerator far enough to form with the caoutchouc; a perfectly tight and convenient a convenient connexion with the second receiver, l, flexible joint is now made by pressing the tube, n, over Fig. 2, which communicates with the first receiver, k, the caoutchouc covering of the end of the worm, 0. The by means of the glass tube, m.

joints of the receivers, Il, are made in the same manner. In order to successfully collect and condense the The vapours which escape condensation in ië pass vapours of such extremely volatile liquids as are now through the receivers, kk and ll, to the refrigerator, B, under consideration, it is of course indispensable that the which contains ice or a mixture of ice and salt, are there apparatus should be constructed with very tight joints ; condensed and fall back into the receivers, ll, which and for greater convenience, but more especially to pre- should stand in a wooden vessel also containing ice or a vent breakage, such of the joints as require to be fre- freezing mixture. The refrigerator, B, is made with quently taken apart should be made flexible. A very double bottom and sides, with an inch space between, convenient and perfectly tight joint of this kind may be which is filled with pulverised charcoal. Being tightly made as follows :— The short stationary tube, n, in the covered, a charge of ice and salt will serve for a long cork of the receiver, k, Fig. 2, is made with the opening day's operations without renewal. In this manner I somewhat divergent upward; the end, o, of the worm have been able to collect in considerable quantity bodies

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CHEMICAL NEWS, 100 On Diffusion of Fluids by the Atomiser, &c.

Sept. 1, 1865. boiling nearly at 0° C., and this from mixtures in which We have here, then, a rare example of the precipitasuch bodies had been quite overlooked by previous in- tion of one of these salts under conditions which do not vestigators.

appear to affect the other. Chlorothallate of ammonia, It will be observed, on reference to Fig. 2, that the therefore, would appear to be useful in the laboratory larger distilling apparatus is represented as standing in as a means of quickly distinguishing bismuth from lead. a brick tire-place, with brick work, cc, a few inches high, Whether it is of use in completely separating one of built up in front, and a sheet iron apron, DD, folded these metals from the other remains to be decided. above. This is for security against fire in case of acci

Bromothallate of ammonia has the same reaction as the dent, either to the retort or hot bath of oil. As arranged, chlorothallate. the contents of either or both of these could run out and It may be as well to add that chlorothallate of amburn without danger to the operator or the premises, as monia is most easily formed by treating chlorothallic the brick work in front would prevent the liquid from ether or alcohol (see CHEMICAL NEWS, vol. ix., p. 241) spreading beyond the fire-place, and the dropping of the with sal ammoniac. The salt is obtained in the form of sheet iron apron would cause an additional draught, and beautiful colourless six-sided tables, which are soluble thus insure the passage of the flames into the chimney. in alcohol and in water. Instead of placing the apparatus in a fire-place, where that is not convenient, equal security against accidents may be attained by the use of my safety heating lamp,||||

PHARMACY, TOXICOLOGY, &c. 9, Fig. 1, to heat the retort, and safety furnace, p, containing a Bunsen's burner, for heating the bath. The On Diffusion of Fluids by the Atomiser for the Purpuses bottom of this furnace, and also a large part of the

of Deodorisation and Disinfection. sides, is formed of wire gauze, such as described for the at the recent meeting of the British Medical Associasafety lamp.II The gauze upon the bottom need not be permanently attached to the furnace, but may be simply tion, Dr. Richardson explained a process he had adopted laid over an opening cut in the stool or board on which for applying the atomiser for the purpose of deodorisathe furnace is to be placed ; if the furnace be then set of peroxide of hydrogen until saturation occurred, and

tion. He made a mixture by adding iodine to solution upon it, taking care that the joint shall be tight around afterwards concentrated sea-salt in proportion of 25 per the edge, nothing more will be required. A strip of vulcanised caoutchouc, about an eighth of an inch in cent. In this combination a water was produced like thickness, is riveted around the edge of the opening for sea-water, and which was rendered active by being the door. Against this the door tightly closes, so that in one of Krohne's hand atomisers could be diffused in

charged with free iodine and ozone. The solution placed no ignition can take place through the cracks which the finest state of distribution at the rate of two fluid would otherwise remain under the edges of the door, For an apparatus to stand upon the table, the safety

ounces in a quarter of an hour; but in an ordinary bedlamp and furnace are especially desirable. I have also the air so active that ozone test-papers were discoloured

room or sitting-room one ounce was sufficient to render used them for the larger apparatus, placed upon floor of the laboratory.

As a practical test of the by it to the highest degree of Moffatt's scale in from security which they afford, I may relate an incident five to ten minutes. For charging the sick room rapidly which happened to myself. I had left the laboratory - Dr. Richardson said this plan was by far the most

and effectually with active air-in a word, with sea-air for a short time with such an apparatus in full opera- effective of any he had known. A nurse could put the tion, the retort containing nearly a quart of light petro- apparatus into action at once, and could deodorise hour leum boiling below 100° C. Having

been detained longer by hour, according to the directions of the Medical than I expected, on returning I found the laboratory filled with the vapours of hydrocarbons; and on ap

Prac:itioner. proaching the retort, found that the caoutchouc joint, connecting the retort with the elevated worm, had Calabar Bean---Its Alkaloid, by FERDINAND F. MEYER. failed, and that the larger portion of the liquid had dis- SOME sixty beans were kindly contributed by, Professor tilled into the room, having been mainly condensed in Torrey towards the preparation of the alkaloid. A prethe upper worm, and conducted thence down the outside liminary examination proved that the base, as well as its of the retort into the safety lamp. This process was still its salts, were colourless, and whenever they became going on, the lamp being highly heated from the excess coloured a loss was sustained. To avoid evaporation as of fuel thus added to it, but no ignition took place out- much as possible, I adopted the following method :side the lamp. Although this experiment was rather The beans were reduced to moderately fine powder, and injudicious, it furnishes a valuable test of the efficiency repeatedly digested with 85 per cent. alcohol, and then of the safety lamp and furnace.

displaced with alcohol of the same strength. The (To be continued.)

tincture was subjected to distillation, while the residual

powder was boiled with dilute sulphuric acid until all Chlorothallate of Ammonia, as a Reagent,

of the starch had disappeared. The residual extract by M. NICKLÉS.

from the tincture and the acid solution were then mixed,

filtered and precipitated with iodohydrargyrate, the preCHLOROTHALLATE of ammonia completely precipitates cipitate washed by decantation, transferred to a cask nitrate of bismuth. The precipitate is chlorothallate of with good stopper, in which it was treated with a strong bismuth in the form of a white powder. Under the same conditions solutions of salts of lead bonate of soda, and then with ether. The colourless

solution of protochloride of tin in tartrate and bicarremain transparent, with the exception of the basic ethereal solution was distilled, the soft residue redisacetate, which becomes cloudy, the cloudiness, however, solved in dilute sulphuric acid, and again treated with disappearing on agitation.

ether and ammonia. The alkaloid was now obtained as 0|| American Journal of Science, 1862 (2), xxxii. 275.

an almost colourless mass, readily combining to form crystalline salts, but without any distinctive reactions.

Loc. cit.

Water.

CAKMICAL News,
Sept. 1, 1865.
College of Physicians.

101 On dissolving the impure alkaloid in acids, a reddish- solved off, and the same physical impression may be brown substance separates, which, from the experiments made to produce a second picture by a simple application made with it, may be assumed to be inert.-Amer. of a developing agent. Jour. of Pharmacy.

P.S.-Since the above was written, I have repeated the experiment with a pyrogallic development with

similar results. Both the first and second developments PHOTOGRAPHY.

may be made with an iron developer or both with a

pyrogallic. The experiment succeeds without the least On the Nature of the Invisible Photographic Image, difficulty in either way.-Am. Jour. Science and Arts, by MT. CAREY LEA.

vol. xi., No. 118. SOME experiments in which I have lately been engaged stem to me to finally settle the long-contested question PROCEEDINGS OF SOCIETIES. as to the nature of the invisible photographic image, and I hasten to write a very brief description of them.

COLLEGE OF PHYSICIANS. The view that the change which takes place in iodo

On Animal Chemistry." A course of Six Lectures by bromised plate in the camera is a purely physical one,

WILLIAM ODLING, M.B., F.R.S., F.R.C.P. that no chemical decomposition takes place, and neither liberation of iodine nor reduction of silver, has obtained

Friday, May 5, 1865.

LECTURE 4. a pretty general acceptance. But latterly it has been opposed by two distinguished photographers-Dr. Vogel

(Concluded from page 92.) and Major Russel. The former affirms that iodide of producing organic compounds artificially, I will make one

Before proceeding, however, to exemplify this power of silver is never sensitive unless there is a body present or two further remarks upon their natural production. capable of taking iodine from it under the influence of At present we are unable to trace the series of changes, light. And Russel believes that the developed image is undergone by carbonic acid and water, which result in the chiefly produced at the expense of the silver haloid in formation of tartaric acid, or sugar, or fat, or other comthe film.

plex vegetable product. It seems probable, however, that The following experiments seem to me to decisively the process by which such bodies are formed does not close this controversy in favour of the physical theory :- consist in the eimultaneous deoxidation of several atoms of

Experiment 1.-If the iodide or bromide of silver in carbonic acid into one complex molecule, as illustrated by the film undergoes decomposition in the camera, and, the equation used in my last lecture to explain the prostill more, if the developed image is formed at its duction of mannite,expense, the film of iodide-bromide must necessarily be Carbonic anhyd.

Oxygen. Manuite. greatly consumed in the development under the dense

6CO, 7H,0 130 C.H1406; portions of the negative, which it has contributed to form. but that a series of more and more complex, less and less

To stttle this point, I exposed and developed an iodo- oxidised, intermediate bodies are successively formed, by bromised plate in the ordinary manner. Then, instead the fixation of deoxidised carbonic acid upon the first-proof removing the unchanged iodide and bromide by fixing duced compounds. For example, we may conceive mannite in the ordinary manner, I took measures to remove the to be built up somewhat in this manner. By a simultadeveloped image without affecting the iodide and bromide. neous dehydration and deoxidation of two molecules of

This I succeeded in doing with the aid of a very weak carbonic acid, we should first obtain oxalic acid thus :solution of acid pernitrate of mercury. Now, if the

C,H,06 (H,0 + 0)

C,H,04 iodide, or bromide, or both, had been in any way de. Then by a further deoxidation of oxalic and carbonic composed, to form, or aid in forming the developed acids, we might obtain tartaric acid, thus :negative image, when this came to be removed there

i Oxalic acid

C,H,O, should have been left a more or less distinct positive

2 Carbonic acid

C.H206 image, depending upon varying thicknesses of iodide and bromide in the film, much like a fixed negative that

C,H,010 has been completely iodised. Nothing of this sort was

4 Oxygen visible, the film was perfectly uniform, just as dense where an intense sky had been as in those parts which

Tartaric acid

C.4.06 had scarcely received any actinic impression, and looking Lastly, by a joint deoxidation of tartaric acid, carbonic exactly as it did when it first left the camera, and before acid, and water, we might obtain mannite, thus :any developer had been applied.

i Tartaric acid

CH. 06 This experiment seems suffciently decisive. But the

2 Carbonic acid

C,H, og following is for stronger.

2 Water

H, 02 Experiment 2.-A plate was treated in all respects as in No. 1, except that the application of the nitrate of

Cf414014 mercury for renoving the developed image was made by

8 Oxygen yellow light. The plate now showing nothing but a

Mannite

CHO uniform yellow film, was carefully washed, and an iron developer, to which nitrate of silver and citric acid had | The actual occurrence of these particular actions is quite been added, was applied. In this way the original unproven; but that some such actions take place is renimage was reproduced, and came out quite clearly with dered highly probable by a variety of considerations.

Thus, in the gradual development and ripening of the all its details.

olive, we find certain vegetable acids replaced by mannite, Now, as every trace of a picture and all reduced and at a later stage the mannite itself replaced by the less silver had been reinoved by the nitrate of mercury, it is oxidised and more complex oleine. Moreover, the comby this experiment absolutely demonstrated that the pounds formed in one organ of a plant are known to be image is a purely physical one, and that after having transferred, in a more or less altered form, to other organs, served to produce one picture, that picture may be dis- in which they become accumulated ; and it is not im ro

2 Carbonic acid.

i Oxalic acid.

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