618 EXPERIMENT STATION RECORD. 



proposes getting this figure from the specific gravity of the sample taken before and 

 after distilling, using either the Haas or Windisch tables for making the calculations. 



With the "free acid" of wine it is recommended to determine the potassium 

 bitartrate; reduce this (188=75) to free tartaric acid, deduct this value from the total 

 nonvolatile acid obtained by titration, and consider the difference as true free acid. 

 The nonacid extract is then obtained by subtracting both the tartar and true free 

 acid from the total extract. 



A new indicator for use in determining total acidity of wines, E. G. Runyan 

 (Jom: Aiiin: Cliiiii. Soc, 23 {1901), No. n,p)K 40-^-405) .—The author employed the 

 mixture of corallin and malachite green, as recommended by Lachaux, in examining 

 dark-colored juices of the sugar beet. Owing to the good results obtained, the mix- 

 ture is recommended as an indicator in the analysis of wines, vinegars, ciders, and 

 similar products. 



A method of determining' nicotin in tobacco and tobacco extracts, J. Foth 

 {Rev. Internat. Falsi f., 14 {1901), No. l,pp. 12-14)- — A modification of Kissling's 

 method (E. S. R.,5, p. 433). The dried mass is extracted with a nuxture of ether and 

 light petroleum. An excess of normal sulphuric acid is added and tlie liquid titrated 

 with normal sodium hydroxid, 1 cc. of sulphuric acid neutralized lieing taken as 

 equal to 0.0162 gm. of nicotin. 



Three new alkaloids of tobacco, A. Pictet and A. Rotschv {Compt. Rend. Acad. 

 Sci. Paris, 132 {1901), p. 971; abs. in Bui. Soc. Chim. Paris, 3. ser., 25 {1901), No. 13, 

 p. 698). 



Chemistry of tobacco smoke, H. Thoms {Schweiz. Wchnschr. Pharm., 39 {1901), 

 No. 21; abs. in Pharm. Jour., 66 {1901), No. 1607, p. 459; Jour. Soc. Chem. Ind., 20 

 {1901), No. 6, p. 626). — Tobacco smoke was drawn through absorption tubes contain- 

 ing caustic soda, sulphuric acid, etc., and the contents of the tuV)es afterwards exam- 

 ined. The smoke was finind to contain the bases nicotin and pyridin, and ammonia, 

 carbonic and ijutyric acids, carbon monoxid, and 2 volatile oils, one of which could 

 be steam-distilled from tobacco. In 1.5,000 gm. of tol)acco there was 6 gm. of this oil 

 of dark color and smell resembling camomile oil. The other oil was extremely toxic, 

 of dark color and narcotic odor. About 75 per cent of nicotin in the tobacco passed 

 over through the smoke, being afterwards partly decomposed. The ash amounted to 

 20.09 percent of the tobacco burned, and 18.82 per cent of the ash was carbonaceous. 

 The mineral matter consisted chiefiy of carbonates of calcium and potassium, the 

 phosphates of calcium and magnesium, potassium chlorid, silicates, and silica. 



Oflicial method for analysis of tanning materials ( f^. ;S'. Dej)t. Agr., Bureau 

 of Chemistry Circ. 8, pp. '2). — A description of the method adopted at the last con- 

 vention of the Association of Official Agricultural Chemists (E. S. R., 13, p. 412). 



On the determination of formaldehyde, A. G. Cr.\ig {Jour. Amer. Chem. 

 Soc, 23 {1901), No. 9, pp. 638-643). — Theauthor has made an extended study of the 

 methods for the determination of formaldehyde. These methods may be divided 

 into 3 groups: (1) depending on a specific reaction, (2) formation of addition prod- 

 ucts with 'elimination of the elements of water, and (3) oxidation and reduction. 

 Of the various methods tested, that of Legler was found the most accurate, with cer- 

 tain modifications. The requisites to the determination are a normal solution of 

 sulphuric acid, an approximately normal solution of ammonia, the exact strength 

 being immaterial, and a methyl orange solution; 3 oz. bottles with smooth sides and 

 close-fitting soft-rubber stoppers, and a boiler in which they may be immersed to the 

 neck. Place 25 cc. of the ammonia solution in each bottle and to one-half of them 

 add a sample containing 0.5 gm. of formaldehyde. Stopper tightly, place the bottles 

 in the boiler, fill with water to the neck, and boil for 1 hour. Cool slowly and titrate 

 carefullj' with sulphuric acid and methyl orange to the first indication of a color 

 change. The differences between the readings for the blanks and the samples repre- 

 sent the ammonia consumed in normal cubic centimeters; 1 cc. equals 0.0601 gm. of 

 formaldehyde. 



