27 



carl... n tetrarhlorid extract. Tlu- curve also shows that the collaborators obtained 

 Hint.- uniform results from the new modification than from the method as originally 

 state. 1. It may be concluded, therefore, that 



(1) The modified method gives higher and more uniform results. 



(2) It eliminates a tedious and inaccurate distillation. 



(3) It is quicker and :i\es an opportunity to make check titrations on the same 

 sample. 



RECOMMENDATIONS. 



As a result of this year's work, including that reported on page 206, it is recom- 

 ntended 



(1) That this modification of the Allen-Marquardt method be adopted as a pro- 



vi.-ional method i see j>. L'lu . 



(2) That in the present method a second washing with sodium sulphate be pre- 

 scribed. 



(3) That the method for determining the water-insoluble color be adopted as a 

 provisional method -., p. 20 



(4) That the method for the determination of amyl insoluble color be adopted as 

 provisional quant itat ive Mar-h r-i method, p. L'" 



That the Koese method '.riven in Bulletin 107, page 97, be dropped as a pro- 

 visinnal method on account of tlie entirely unsatisfactory results obtained with it in 

 the jmst two or thn 



Mr. Tolman e.-illed mi Mr. Ki>eher, of the Bureau of Standards, who 

 spokr iii re'_ranl t the neees>ity of unifyiiii: the alcohol tables. He 

 called attention t.i tin' fact that two tables are now in use by the 

 Treasui] Department and a third by the Association of Official 

 Airricnlttiral ChemM-. Th<> disadvantages to chemists and practical 

 \\orkers frnin such a condition of affairs bciny; obvious, it was strongly 

 1 1 mended tliat the association take some action in the matter. 

 A table based mi t he calculations of Mendeleeff was recommended by 

 Mr. KiM-lier. The (jue^timi <>f temporatiiro was also discussed, and 

 the whole matter \\ u temporarily referre<l to Committee C on recom- 

 mendati..nv ,f referees, the chairman naminjj: the following members 

 t.. >ervr on ibis committee: Me--r-. Tolmaji, Winton, Hortvet, Bart- 

 let t. and .lall'a. 



REPORT ON VINEGAR. 

 By CHAKI M II. HICKKY, Asxnn'tite Referee. 



The work which has been don. by or reported to the referee deals largely with the 



lead number i'-r pure rider vinegar and other pure vinegars. The cider vinegars used 



by the referee wen- made by the old-fashioned, slow process. The method employed 



lilar to the one by which Winton and Kreider analyzed maple products, with 



modifications to make it applicable to vinegar. The number of grams of lead 



pre< f pi t at e i I >y 100 cc of vinegar is taken as the lead number. Other data are included 



to make the results more complete. The method as modified by the referee is as 



follows: 



Pipette 25 cc of vinegar into a 100 cc flask; add 5 cc of a standard lead subacetate 



solution and dilute to KX) cc. Let stand at least one hour, then filter and pipette out 



a- filtrate. To this add 10 cc of dilute sulphuric acid and 100 cc of 95 



percent alcohol; let stand over night; filter through a porcelain gooch crucible; wash 



aj. Amer. Chem. Soc., 1906, 28 : 1204. 



