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, t h e foliowing is t h e most satisfactory method of procedure. I O cc. of the oil is p u t 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 t h e chnracteristic blue reaction, a t the junction nliere tlie psper has bee11 nioisteiied. 111 t h e 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 t h e iiioistened starch iodate paper at t b e elid of t h e condeiisiiig tube. T h e distillation should not be cni-ried 011 t f J o rapid!.. In coiiclusioii, t h e writer would ita:e t h a t very good results mere obtained it1 deteriiiining t h e 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 t h e annual coiivention of the Associatioii in 1905, this committee reported a iiietliod for t h e 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, t h u s including all the determinatiorls ustially made on iron in n-liicli occasion for difference between t h e buyer a n d seller is a p t to arisi.. T h i s report will therefore include all t h e methods decided upon. W e would d s o like to call attention t o t h e following quotation from t h e report of r g o j , which indicates tile intentions of these methods. "In rt~oiiiiiientiiiigt h e 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 t h e 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 tlie Aiiiericaii F o u t ~ d r ~ ; m e nAssociation, 's I'hiladelphia Coii\rentioii JIay 21?-24,1907.
