On defects in the apparatus generally used for the determination of bisulphide of carbon in coal gas : and description of a new apparatus for its estimation / by Alfred G. Anderson.

  • Anderson, Alfred G.
Date:
1867
Catalogue details

Licence: Public Domain Mark

Credit: On defects in the apparatus generally used for the determination of bisulphide of carbon in coal gas : and description of a new apparatus for its estimation / by Alfred G. Anderson. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    The force of the current of air soon carries the excess of fluid ■which has thus accumulated in No. 2 U-tube into No. 3; then into No. 4, and so on, until, by traversing successively from one tube to another, it finally collects in the bottle g. If this last vessel be provided of considerable capacity (and this should on no account be overlooked), it will safely retain any of the fluid of the TJ-tubes which from any cause may be carried over in this way. It is always advisable to place a bottle, fitted up as described, to intervene between the|U-tubes and the “ aspirator,” as sketched in the drawing, notwithstanding that we have not omitted to observe that every one of the U- tubes has been furnished with the bulbs bio wn in them, which, in my experience, I always find effectual in preventing the contact of the enclosed solution with the corks, even when very brisk agitation of it occurs. The addition of this bottle, g, is a sure safeguard against the possibility of loss being incurred, if, from some want of caution in putting the “ aspirator ” into action, a sudden rush of air through the tubes forces portions of liquid with it into the last 17-tube, d\ until it becomes filled, or nearly so. Then, but for the bottle g occupying its position in the arrangement (in which so long as the lower extremity of the short tube q remains out of reach of contact of the liquid carried over into it every drop of fluid collecting there will be securely held), the experiment would be completely spoiled from the loss arising by the passage of some of the alkaline solution, with its condensed sulphurous products, through the tubes r and H into the sink. I am thus careful in describing the precautions it is absolutely necessary should be observed to avoid a useless expenditure of time and trouble by others, who, with a view to estimate sulphur in this manner, may put this system into operation, from the fact that in my first one or two attempts to apply it, I experienced a good deal of vexation through accidents arising from non-observance of the small details which I have here taken some pains to point out. If we would entirely avoid the mortification of failure, we must pay strict attention to setting up the apparatus with the safe- guards I have particularized. If potassa solution be the absorbing fluid selected for charging the tubes, in preference to ammonia—and in my earliest experi- ments I uniformly employed it for this purpose—as potassa which is usually kept in laboratories nearly always contain more or less sulphuric acid, one of two courses must be adopted in this case : we must either purify the solution of potassa in a way that will enable us to be completely rid of this sulphuric acid, or, what is far more convenient, prepare a few pints of the unpurified potassa solution, then take a weighed quantity of this, and pass a current of chlorine into it until no more of that gas is absorbed; boil for a few minutes, after feebly acidifying with a few drops of hydrochloric acid; filter; add sufficient solution of chloride of barium to throw down all the sulphuric acid; filter after allowing twenty-four hours for subsidence; wash dry, ignite, and weigh the precipitate thus obtained. It is only then necessary that the potassa solution be weighed before being placed in the U-tubes. A flask is, therefore, selected which will about hold the necessary quantity of the potassa solu- tion adequate for this purpose, and it is, with its contents, then