T H E J O U R K A L OF IA7DUSTRIAL forms may be mentioned the following: It can easily be cleaned. The pratinum spiral extending the full length of the tube insures complete combustion. This spiral can readily be removed for repairs in case of injury. The apparatus is convenient to handle and owing to its tall form connects with a Hempel pipette without the use of a stand. The apparatus can be obtained from Messrs. E . H. Sargent IT-ILFRED W.SCOTT. & C o . , Chicago.
DETERMINATION OF INSOLUBLE PHOSPHORIC ACID. * Ever since the organization of the Association of Official Agricultural Chemists the Official method for the determination of insoliible phosphoric acid has been confined to the one process; that is, digestion in neutral ammonium citrate for a definite length of time a t a stated temperature. From time to time some slight modifications have been proposed, b u t in the main, the method remains practically the same as i t was twenty-five years ago. One difficulty which has been experienced, is to make a n ammonium citrate which is exactly neutral, owing to the indefinite action of the solutioii on different indicators. The “official” method prescribes corallin as the indicator to be used in testing the neutrality of the solution. Any one who has tried this indicator knows how unsatisfactory i t is, and i t is safe to say that there is not one chemist in ten who depends upon i t for the final test. The optional method provides for first neutralizing with corallin as the indicator, and making the final test with cochineal after precipitating out the citric acid with calcium chloride. This procedure is also unsatisfactory, and as Dr. McCandless, referee of phosphoric acid for the A. 0. A . C. for the past year, truly said: “If a chemist has succeeded in getting his solution neutral or practically so, he will almost certainly get his out of joint b y attempting to make i t exact with calcium chloride solution.” The result is that different chemists employ different methods for standardizing the ammonium citrate solution, and hardly t u o solutions will be found of exactly the same neutrality. Instead of prescribing two methods which may give entirely different results the A. 0. A. C. should prescribe one method which can be easily worked and would prove satisfactory to a majority of the chemists who are engaged in fertilizer work. Dr. McCandless favors making the solution neutral by analysis, and calculating the exact quantity of ammonia or citric acid to be added. A citrate solution which is neutral b y analysis is distinctly alkaline b y the ordinary indicator, and while i t would be quite a departure from the Official method, i t would a t least insure a greater degree of uniformity than i t is possible to obtain under the present methods. It is fortunate that a slight deviation from strict neutrality has no appreciable effect in the ordinary acidulated goods, b u t in cases of bone, tankage, etc., i t is very important that the solution should be neutral. There is another point that seems to have been overlooked in carrying out this method which causes quite wide variations in results by different analysts; that is, the manner of filtration after digesting with ammonium citrate. I have investigated the question to some extent, and find the following methods of filtration in use in different laboratories. Through asbestos in Hirsch funnel with filter 1 Paper read before the Division of Fertilizer Chemists at Baltimore, December 31, 1908.
pump; through asbestos on carbon filter with filter pump; through filter paper on Hirsch funnel with filter pump; through filter paper in Buchner funnel with filter pump; through filter paper with regular funnel and platinum cone using filter pump ; through folded filters without filter pump. The filter papers used in the above vary from very thin to dense slow filtering papers. Experiments which we have made by these different methods show that the results will vary on some samples of acid phosphate having a high percentage of insoluble from 3 per cent. to I per cent. and on such materials as ground bone, tankage, reduced phosphate, basic slag, etc., it is probable that there would be much larger variations. The exact wording of the “official” method with reference to the filtration is as follows: “ A t the expiration of exactly thirty minutes from the time that the filter and residue are introduced remove the flask from the bath, and immediately filter the contents as rapidly as possible.” Now if this were amended so as to specify the exact method of filtratiun and the kind of paper to be used, much of the confusion in results would be avoided. Taking everything into consideration, this method if properly executed, serves the purpose for which i t was intended in a very satisfactory manner, and these few comments are presented with the hope that this division will take up the question and evolve a method which‘will not only be acceptable to the fertilizer chemists, b u t will be adopted by the Association of Official A4griculturalChemists. F. B. CARPENTER.
COUNCIL ON PHARMACY AND CHEMISTRY, REGULATIONS RELATIVE TO N E W AND NONOFFICIAL REMEDIES. The last meeting of this Council of the American Medical Association was devoted to the discussion of the revision of the rules, and rearrangement of the matter contained in the “New and Non-Official Remedies.” I t was decided that this book shall contain descriptions of the proprietary articles accepted b y the Council and of such simple nonproprietary and unofficial substances as are of sufficient importance. I t was decided that proprietary mixtures unless they show originality and a marked advance over similar products, shall not be included in the main body of the book, but when they conform to the rules, they shall be included in form of an appendix to the book. Rule 5 n a s so amended as to require that the actual identity of the manufacturer of a product be furnished. The Council voted to interpret Rule 8 so that after January first, 1909, pharmaceutical preparations and mixtures will be admitted only under a pharmaceutical title which shall indicate the most potent ingredients. Arbitrary coined titles will not be recognized for Pharmaceutical mixtures. I t was also decided that no pharmaceutical mixture shall be accepted whose name indicates its therapeutic action or is suggestive of the names of diseases or pathologic conditions in which i t is to be used. After January first, 1909, this rulc is to be extended to simple articles. The Council voted to condense Rules 9 and IO to become Rule 9 and adopted a nen Rule, S o . IO, under nhich recognition will be refused to articles which, because of their unscientific composition, are useless or inimical to the best interests of the public or of the medical profession.
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T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERIA-G C H E M I S T R Y
These rules represent a material progress made in the gradual elimination of deception and fraud which has been in pTactice, without restraint, for many years. During recent years, with the great influx of newer remedies, there has appeared in the European and American markets, a large number of preparations, so named and labeled a s to suggest either their therapeutic action, or similarity to other established true synthetics. These preparations, being mechanical mixtures of well-known therapeutic agents, are therefore calculated to deceive the medical profession, and considering the persistence with which they are pushed, i t is high time that concerted action be taken by chemists, physicians and pharmacists on both sides of the Atlantic, in order to control this nuisance. V. COBLENTZ.
QUOTATIONS. THE OXIDATION O F ATMOSPHERIC NITROGEN. By DR.
OTTO S C H N E I D E R .
(Lecture delivered before the Verein Deutscher Chemiker, 1908; Authorized translation-Extracts.)
I n the process of the Badische Anilin & Soda Fabrik, electric arcs produced by powerful currents and of a length never before attained are used. But these arcs burn very quietly, and special care is taken to displace them as little as possible by the motion of the air by causing the air to flow along the arc in the direction of its length. This way is so entirely different from the traditional one that there was no lack of dissenting voices who called in question the practical utility of our method, and curiously enough, by giving diametrically opposite reasons. Some said that this method of conducting the air did not allow i t to come sufficiently in contact with the arc, while others claimed that i t remained in contact too long. Well, in the meantime we have demonstrated that our process can compete successfully with any other, The principle of the process consists, as we have already indicated, in conducting the gases to be acted upon along a quietly burning electric arc of great length, in surrounding, as i t were, the electric arc with an advancing mantle of gas. The apparatus with which the operation is conducted is as simple as the principle itself. It consists essentially of a tube in the axis of which the electric arc is quietly burning surrounded by a mantle of the gases which are to be combined. The tube itself and the motion of the air in i t must be so arranged that any one-sided motion in the direction of the arc is avoided as perfectly as possible, while i t does no harm if the air comes from two opposite sources or is introduced towards the arc through a slit with equal pressure from all directions a t once because this does not disturb the position of the arc. Now, there is one kind of motion which satisfies this condition part'cularly well. For this reason we have used i t almost exclusively in our method on a large scale. It enables us to obtain arcs of enormous length, which a t the same time are so stable that they can burn for weeks without having to be relighted. This is a motion of the air which in spite of the greatest rapidity permits that portion of the column to remain a t rest in which the arc is situated. This kind of motion is familiar to you all, it is the spiral or vortex motion. You all know with what devastating power cyclones visit certain regions of the earth with terrifying regularity.
They move like a solid mass across the country for miles laying low everything before them. Nothing is able to withstand the impact of this whirling air and yet they carry in their centre a region of calm. We have utilized this phenomenon. We generate such a vortex in miniature in our tubes and in its calm centre we maintain our electric arc. The particles of the air rush along the arc in a rapid screw-like motion and are combined in the desired way. I n this way electric arcs of almost any desired length may be kept burning quietly. The tube may be made of any material. We take for example an ordinary iron gas-pipe. An electrode insulated from the pipe is attached on the inside a t one end and the air is introduced at this end. The insulated electrode is connected with one pole of a high tension current and the pipe itself with the other pole. The whirling motion of the air is produced in the simplest possible manner by tangential introduction. The arc is then lighted in any desired way. I will not mention the different ways in which this can be done, as they are well known to every electrician. It is immaterial which way is chosen in our process, because, as we have already stated, the arc when once lighted can be maintained for weeks without relighting, I n the simplest form the arc may be started by making the distance between the pipe and the electrode so small that i t will be overcome by the tension of the interrupted circuit. As every electric arc must be provided with an inductive resistance which is indispensable to produce quiet burning and which is present in every ordinary alternating current arc lamp, the tension between the electrode and the pipe is diminished by a certain amount as soon as the arc is lighted and with this diminished tension the current will not jump across again as long as the arc continues to burn. If i t should go out for any reason, a new arc will be formed of itself because of the renewed increase in the tension. With this method of forming the arc the air enters the tube below the electrode and pushes one end of the arc, which is quite short a t first, rapidly before i t along the wall of the pipe. As soon as stability is reached, which comes to pass so quickly that the eye is hardly able to follow the process, the result is an arc which burns quietly in the axis of the pipe, its end being far from the electrode attached to the centre. This end is a t that point of the wall of the pipe where the gases have become so hot as to acquire sufficient conductivity for the current to jump across them. The location of this point depends entirely on the conditions adopted. Of course the place where the arc terminates must be cooled off by means of water or in some other suitable way. The method of starting the arc which has just been described requires a very narrow space between the pipe and the electrode. A certain pressure is used to make the air which is introduced pass through the narrow space. This inconvenience is avoided by introducing the greater part of the air above the electrode, or by increasing the space, and producing in some way a brief temporary short circuit between the pipe and the electrode, as for example by means of a rod introduced from the outside, or an induction spark or a slender flame and the like. I t does not matter because the arc when once lighted properly keeps on burning quietly, as has been stated, without going out. The tube may also be made of non-conducting material, such as fire-clay for example. I n that case the arc must be
