NOTES. The Qualitative Detectioii of Si1@1izuDioxide in Lizseed Oil, Efc.--A rapid :uid sensitive method for detecliiig sulphur dioxide iii various oils, by iiieaiis of starch iodate paper, has been used hy the writer, Kith snccess for a period of several years. Starch iodate pnpcr is made by inimersiiig filter paper in t h e foiiowing solution, n i i d drying slonly. io0 cc. of boiling distilled water, is added to two gi-ailis of !-taIch, c21'e beiiig taken to prevent luiiips, then 0 . 2 gram of pota. iiii iodate, which has been dissolved in 5 cc. of cold distilled water is added to tlie starch solution. 011testing a suspected sample of linseed oil, or other oils, n.hicli are of a high boiling point, the foliowing is the most satisfactory method of procedure. I O cc. of the oil is put into a test tube, about I j o X 18 inn]. and a strip of tlie iodate paper, which has been slightly moistened half its length, is suspended in t h e mouth of tlic test tube. T h e oil is gradually lieatetl until near the boiling point, w i i m , if sulphur dioxide is present, it will appear itistnntiy, by the chnracteristic blue reaction, a t the junction nliere tlie psper has bee11 nioisteiied. 111 the case of !ow boiling oils, such as washed petroleum, and coal tar oils, etc., i t is most suitable to cli~till109 cc. in a glass distiliing bulb, using a short Liehi: condenser, 2uid placiiig the iiioistened starch iodate paper at tbe elid of the condeiisiiig tube. T h e distillation should not be cni-ried 011 tfJo rapid!.. In coiiclusioii, the writer would ita:e t h a t very good results mere obtained it1 deteriiiining the presence of very slight traces of sulphur dioxide, Ivliich could not be practically determined by any other method. HESRYC.FKEY. 2\21 Keynoids St.. I'hiIr+c~eIpliia,
of- the Comim'ffe~cox S t t r ? z ~ ~ ; 2 ~ n l e t i 2 o d sf lhberA?in&sis of/r072 :A t the annual coiivention of the Associatioii in 1905, this committee reported a iiietliod for the tleteriiiiiiatioii of silicoii in iron, and last year adt1i.d methods for deterniiniiig total carbon and sulphur. T h e committee iiow adds methods for determining graphitic carbon, riiangaiiese aiid phosphorus, thus including all the determinatiorls ustially made on iron in n-liicli occasion for difference between t h e buyer and seller is apt to arisi.. T h i s report will therefore include all t h e methods decided upon. W e would nlso like to call attention t o the following quotation from the report of r g o j , which indicates tile intentions of these methods. "In rt~oiiiiiientiiiigthe above iiiethod, it was recognized that it is almost a n impossibility to get chemists to use a staiidard method iii their daily work. Hence the above method, as recommended, is intended priui:iril~as a check method in case of dispute between laboratories, or a< ixtivecii buyer aiic! seller. RefloiY
I I:rolri Trniisactioiis of the Aiiiericaii F o u t ~ d r ~ ; m e nAssociation, 's I'hiladelphia Coii\rentioii JIay 21?-24,1907.
NOTES
1373
“Hence a method accurate in every point was sought, shortness being sacrificed to some extent to insure accuracy or against t h e chance of error by a careless operator. Little in the above is left to the judgment of t h e chemist. “It will be further recognized that in the purchase and sale of pig iron o r castings under specification, that standard methods are essential i n in order to allow the parties of both parts to make their determinations with the assurance that, on the score of method, they are on the same footing. ” W e wish also to emphasize the ideas involved in the selection of members of this committee-that is to have representatives from conimercial laboratories as well as works chemists, and to have members from different sections of the country. T h e success in carrying out these ideas will be seen by the following list of members : Andrew A. Blair, Booth, Garrett & Blair, Philadelphia. H. E. Diller, chemist, Western Electric Co., Chicago. H. E. Fieid, metallurgical engineer, Mackintosh, Hemphill & Co., Pittsburg. R. F. Flinterman, chief chemist, McCormick division, International Harvester Co. , Chicago. Allan P. Ford, metallurgist, Eaton, Cole & Burnham Co., Bridgeport,
Conn. J . 0. Handy, chief chemist, Pittsburg Testing Laboratory, Pittsburg. J. R. Harris, chief chemist, Tennessee Coal, Iron & Railroad Co., B i r rui n g ha m , A 1a. H. C. Loudenbeck, chief chemist, Westinghouse Air Brake Co., Pittsburg. R. S . MacPherran, chief chemist, Allis-Chalmers Co., Milwaukee. W. G. Scott, chief chemist, J. I. Case Threshing Machine Co., Racine, Wis. Henry Souther, Henry Souther Engineering Co., Hartford, Conn. Prof. Thomas B. Stillman, Stevens Institute of Technology, Hoboken, N. J. Deierminafioiz of S i l i c o z -‘ ‘Weigh one grain of sample, add 30 cc. nitric acid ( I . 13 sp. g r . ) ; then j cc. sulphiiric acid (coiic.). Evaporate o n hot plate until all fumes arc driven off. T a k e u p in water and boil uiitil all ferrous sulphate is dissolved. Filter on an ashless filter, with or without suction pump, using a cone. Wash once with hot water, once with hydrochloric acid, and three or foiir tiiiies with hot water. Igiiite, weigh, and ewporate with a few drops of sulphuric acid and 4 or j cc. of hydrofluoric acid. Ignite slowly and weigh. Multiply the difference i n weight by 0.4702, which equals the per cent. of silicon.” Defermiizatioz of
[email protected] slowly a three gran: sample of drillings in concentrated nitric acid in a platiiiuni dish covered with a n inverted watch glass. After the iron is coriipletely dissolved, add two grams of potassium nitrate, evaporate to dryness and ignite over a n alcohol lamp at red heat. Add j o cc. of a one per cent. solution of sodium carbonate, boil for a few minutes, filter, using a little paper pulp in the filter if desired, and wash with a hot one per cent. sodium carbonate solution. Acidify t h e filtrate with hydrochloric acid, evaporate to dryness, take u p with 50 cc. of water and two cc. of concentrated hydrochloric
I374
NOTES
acid, filter, n-ash and after tiilutiiig the filtrate to about I O O cc. boil and precipitate with barium chloride. Filter, wash well with hot water, ignite and weigh as barium sulphate, -iv!iich contailis 13,733 per cent. of s ul ph iir . Dcfcrmi7zniioit of Phos@ilo~us. Dissolve two grams samples in 50 cc. . I . 13), add i o cc. hydrochloric acid and evaporate to nitric acid ( ~ pgr. dryness. In case tile sample contains a fairly liigh percentage of phosphorus it is better t o use Iialf t!ic ximve quantities Bake until free from acid, redissolving iii 2 j to 30 cc. of concentrated hydrocliloric acid, dilute to about 60 cc., filter and wash. Evaporate to about 25 cc., add 2 0 cc. concentrated nitric acid, evaporate until a film hegins to forin, add 30 cc. of iiitric acid (sp. gr. 1.20) atid agaiti evaporate iintil a film ixgiiis to forrii. Dilute to about I jo cc. with hot water and allow i t to cool. 'CS'Iien tlie sclution is iietrveen 70' and Soo C.add 50 cc. of molybdate solution. Agitate t h e solution a few minutes, then filter o n L: tared Gooch crucible iiaviiig a paper disc a t the bottom. Wadi three times with a three per cent. nitric acid solution and tn.ice with ;ilcoliol. Drj. at 100'I O j o to constant weight. T h e weight multiplied by 0.0163 equals t h e per cent. of phosphorus in a one gram s:~iiiple. To make the molybdate solution add roo granis molybdic acid to 250 co. water, and to this adtl I jo cc. arniiionia, theii stir until all is dissolved aild add 6 5 cc. iiitric acid ( 1 4 2 !;1>. gr.). RI:tke another solution by adding 400 cc. concentrated :iitric : r i d to i 100 cc. water, :ind Tvlien t1:e SOlutioili: are cool, Iwiir the fint ;j!o~vl\. into the second wit11 coiistant stirring and adtl a couple of drops of niiiinoniiiiii phospliate. ~ I e f e i ~ w ' ~ i z f(I#i e ~~:~ Z m z g a i ~ ~-1)issoIve sc. one :iiitl one-tenth granis of drilliiip in 2 5 cc. iiitric acid ( I . 13 sp. gr.)filtitr into a11 Erlenmeyer flask mid \v.1*;!1 wit!; 30 cc. of tlic same acid. Then cool and add :Lbout onehalf grii::~ of sodiuiil bisiiiuthate uiitil a perinanent pinlr color forms. H e a t until tlic color has disappeared, with or without tlie precipitation of rnanganese dioxide, and then add either sulphurous acid or :t solution of ferroiis sulphate until the solution is clear. Heat until all nitrous ; add an excess of oxide fumes iiavc lxen driven ofi, cool to aliout :
