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UNIFICATION OF TERMS USED IN REPORTING ANALYTICAL RESULTS.1. Cyril G. Hopkins. J. Am. Chem. Soc. , 1907, 29 (9), pp 1312–1314. DOI: 10.1021/ ...
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CSNII, G. H O P I ~ I S S

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PS,H+ 2 0 : - -H N , SH:,- - 2H,O, aiiiounted to 13.55 per cent. of the theory T h e highest yielti of aiiiinoxia aniouiitetl to 2 1 . 3 per cent. 011 the basis of the same equation. T h e w e of aiiimotiiutii inetava11adate i i i t h e determination of hydrazine, as recoiiiiiiended h y Hofniarin ant1 KUspert, is theoretically subject to a percentage error nunierically eciuivalent to t h e percentage yield of hydronitric acid ~ I i e i ithe nitrometric nietliod is employed, and to a smaller error \vlien the oxitiiiiietric riietliod is cliosen. Ey the use of a Luiige nitrometer the error was fonnd to IJe iiietiiod and about one per cent. about 4.j per cent. for t h e riitro~i~etric for the oxidinietric method.

_____ UNIFICATION

OF TERMS USED IN REPORTING ANALYTICAL RESULTS.' H o m r s s , Chairninii of Cominittee fro111t Aniericnii .4gricu!tliral Ccilleges n i i d Experitnet Keceive(! Jill!. 5, 190;.

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I11 1904 a t t h e S t . Louis meeting of the Association of Official Agricultural Chemists, a coniiiiittee was appointed 011 unification of tei'iiis \\sed in reporting analysis ; and at the Des hfoiiies meeting a similar COTIJniittee was appointed by tlie Association of Xiiiericari Agricultural Colleges and Experinleiit Stations. These t\?.ocoiiimittees Iiav- cooperated in t h e n-ork assigned 311d at the last annual iiieetiiigs made substantially tlie same r e p r t to tiieir respecti1.e asso cia ti 01 is , Filial action oil tlie report was postpoiled for one year by the .Asboci::tion o f Oficial Agriciilturai Chemists a t \ ~ 7 a s h i r i g t olast ~ ~ Soveinbe!-, i n part, lwcniise :It t h a t time 1 1 0 action had heen taken h\- the 1)roader associntioii of Igriciiltura! College:; :ilitl Exlm-iiiiciit Stations, lvliose a n n u n l colil,-c:it;on \;as lie16 a week Inter a t Iiatcj:i Rouge. nt wliicl: iiiectitig. llO.$tL \.i.r , the report wliicli follows \vas adopted with t h e contlitioiis .stated : Report of Committee on Unification of Terms Used in Chemical Analysis. "\'our coiriiiiittee has been working iri cooperatioil witli a similar coni:nittee froin tlie Association of Official Agricultural Chemists, a11d the follo\viyg; report is in hariiioriy with a report x!ready made t o that associatioii b!. its ow11 coininittee, on which actioii was postpoiied for m e year. T h e sul-rject-matter referred to your cotnmittee iiaturally divides itself iiito two clasiej, oue of wliicli includes soils, fertilizers, ash and other iiiaterials whose analysis may be espressed in terms of clieiiiical elements o r i i i simple compouiids ; while the other class includes foodstuffs, coridiiiients, and other materials n h o s e analysis riiny t lx expressed in terms .^1

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UNIFICATION O F TERMS

of niore complex compounds, or groups of compounds, which actually compose or are contained in t h e material.

Soils, Fertilizers, Etc. Special efforts have been made during the past two years to secure a full consideration, especially b y directors of experiment stations, chemists, and agronomists, of t h e question whether i t is better to continue to report analysis of soils and fertilizers on the 1)asis of oxides (excepting nitrogen, which is already most commonly reported as t h e element), o r to report such analysis on the uniform basis of the elements. Several circular letters h a r e been sent o u t , a n d i n answer to this question 85 replies have been received. Of these there were 2 1 making comments, but expressing no definite o r final opinion on the question ; there were 16, including 1 2 chemists wlio favor retaining the present system ; while there were 17 chemists, 16agronomists, and 15 directors a n d other officers, o r 48 in all, who expressed definite opinions in favor of adopting the uiiiform system of elements. In view of these facts, and providing concurrent action is taken by the Association of Official Agricultural Chemists and t h e American Chemical Soc‘iety, your cominittee favors t h e adoption of t h e element system for reporting analytical rcsults i n t h e analysis of soil-;, ashes, and fertilizers as rapidly as possible, and recommends that t h e association urge those responsible for fertilizer legislation to h a r e the laws changed if necessary, and as soon as practicable to meet with these recommendations, i f concurred in. T h i s would necessitate t h e adoption of t h e dual system of expressing resiilts temporarily in some States, but it is hoped that when fertilizer laws are adopted to meet these requirements some definite time will be set, at t h e expiration of which oiily the element system will appear on the bags or tags. It is therefore suggested that n o other terms than those of t h e element system be allowed after t h e year 1916. Your committee also recommends, provided the foregoing is adopted, that this association adopt some definite form for stating t h e composition of fertilizers and fertilizer materials. T h e following forin is suggested. Elements Guaranteed.

Available iiirrogeii. .................... Inert nitrogen.. ...................................... ~ l ~ a i l a lphosphorus. ~le ................................ Inert phosphorus. .................................... Available potassiam.. ................................ Inert potassiuni .....................................

Per Cent.

W e recommend t h a t the ternis I ‘ available ” a n d ‘ ‘ inert ” shall be used in harmony with t h e construction placed upon them by the Association of Official AgriculturaI Chemists. T h e committee also recommends t h a t in case of t h e adoption of t h e

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foregoing there be required to be printed on t h e bag o r on t h e t a g to be attached to t h e bag o r to accompany fertilizers sold in bulk a n explanatory statement naming t h e materials in which t h e plant food is carried, as, for example : T h e plant food guaranteed i n this fertilizer is carried in cotton-seed meal, potassium chloride, a n d acid phosphate. Foodstuffs, Condiments, Etc. I n t h e case of foodstuffs, condiments, etc., your coinmittee recommends iu t h e statement of analytical results t h e use of names of compounds ( o r groups of compounds) actually present as such i n the material, this being in accordance with t h e present practice. Your committee asks for further time in which to consider t h e more complete unification of systems for reporting results of aiialysis of some miscellaneous materials, as insecticides, baking powders, etc. I t is further recommended that this association appoint a committee t o aid (preferably i n cooperation with a similar committee from t h e Association of Official Agricultural Chemists) in trying to bring ahout both iiational and international uniformity in t h e reporting of analytical results.” T h i s report with t h e conditions stated as presented by t h e committee was adopted by t h e Association of American Argicultural Colleges and Experiment Stations, and on behalf of t h a t association I now present this report to the Xmericaii Chemical Society and ask for its endorsement. YSIVI:RSI’I’Y01.‘ ILLISOI?, I ’ r l I R t l n , III.

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CONTRIBUTION TO THE DETERMINATION OF PHOSPHORIC ACID VOLUMETRICALLY. BY W. D. RICHARI)SOS. Received J u l y r i t h . r g o j .

It is a fact fairly well known ainoiig agricultural chemists t h a t when phosphoric acid is determined i n acid phosphate by the Peniberton ~ o l umetric method or its usual modifications results are obtained which do not agree with those obtained by t h e gravimetric method of the A . 0. A . C. and t h e error frequently amounts to I per cent. P,05. Inasmuch as t h e volumetric method in general agrees well with t h e gravimetric and as i t is a desirable method to use, a search nus made in this laboratory for t h e substance which caused t h e discrepancy. A check satnple of a n ordinary r u n of acid phosphate was sent out to a number of chemists a n d the results were in accord with previous experi. euce, that is differences amounting in t h e extreme case to I . 2 per centP,O, were recorded. Following this, mixtures of inicrocosinic salt and the impurities usually present in acid phosphate, namely lead salts, fluorides, arsenic compounds and silicic acid were made and t h e P,O., in them

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