268 TOBACCO PRODUCTION IN THE UNITED STATES. 



2. NICOTINE was determined in ten grammes by the method of Schloesing, as described by Grandeau 

 (Handbvch fiir Agricuttur-chcmisclie Analyse: Berlin, 1879, p. 194), namely, by exhaustion with ether after making 

 the sample strongly alkaline with ammonia, evaporation of the ether and titratiouof the residue with deci-normal 

 sulphuric acid. 



3. PECTIC ACID was also determined by the method of Schloesing, as described by Grandeau. 



4. STAKCn was determined in the residue from which the pectine substances had been removed by inversion 

 to glucose by the method of Sachs (Corr. Blatt d. Vereins analytischer Chemiker, ii, 15, 21, and 25, and Jour. Am. 

 Chcm. Soc., i, 540) and gravimetrical determination of the glucose with Fehling's solution, as described in the case of 

 sugar. 



5. SUGAR. Ten grammes of tobacco were exhausted with 85 per cent, alcohol, the extract evaporated to 

 remove the alcohol, the residue dissolved in water and made up to 500 cubic centimeters. One hundred cubic 

 centimeters of the solution were then measured off, treated with excess of basic lead acetate, filtered, and the 

 filtrate and washings of the precipitate brought to the volume of 200 cubic centimeters. The solution was then 

 made alkaline with sodium carbonate, treated with a moderate excess of Fehling's solution and heated for twenty- 

 five minutes to a temperature of 75 C. to 80 0. The cuprous oxide was then collected on a weighed filter and the 

 equivalent of the precipitate in glucose calculated from the results of check determinations made under the same 

 conditions with inverted cane sugar. A second portion of the original solution was then subjected to the process 

 of inversion, after precipitation with lead acetate and treated as above with identical results showing that no cane 

 sugar was present. 



6. NITRIC ACID was determined by exhausting the tobacco with 85 per cent, alcohol, evaporation of the extract,, 

 re-solution in water, and then proceeding by the method of Schultze (Zeitsclirift f. anal. Chemie, 1870, 401 ); the 

 error (a slight loss) incident to the method as originally described being compensated for by the addition to the 

 solution under examination of a measured quantity of solution of sodium nitrate of known strength, the volume 

 of gas yielded by the latter being deducted from the total volume obtained in the analysis. The graduated tube 

 containing the soda solution was also caused to dip into mercury during the evolution of the gas, to prevent loss by 

 the " churning up " of the gas with the liquid, and the attendant escape of small bubbles from the tube. 



7. CITRIC, MALIC, OXALIC, AND ACETIC ACIDS were determined substantially by the methods of Schloesing^ 

 as described by Grandeau. 



8. TOTAL NITROGEN was determined by the method of Dumas, and corrected by the results of "blank" 

 combustions made under precisely similar conditions with pure sugar. In the case of the tobaccos which contained 

 no nitric acid duplicate nitrogen determinations were made by the soda-lime method, with closely accordant 

 results. 



9. AMMONIA was separated from nicotine, and determined by the excellent method of Nessler (op. cit., p. 144),. 

 namely, the ammonia was liberated with freshly ignited pure magnesia, distilled into dilute sulphuric acid, the 

 solution carefully neutralized with sodium carbonate, and the nicotine precipitated with mercurio-potassic iodide. 

 The liquid was then filtered, filtrate and washings treated with an excess of sodium mono-sulphide, the ammonia- 

 redistilled into deci-normal sulphuric acid, and the amount determined by titration. 



10. BESINOUS AND FATTY SUBSTANCES. The tobacco was exhausted, first with ether, then with absolute 

 alcohol, the solutions evaporated to dryness, the residue digested with dilute sulphuric acid, thoroughly washed with, 

 water, dried at 100 C., and weighed. 



11. CELLULOSE (CRUDE FIBER). The determinations were made by the method described by Wolff. (Chem. 

 Untersucliung landirirthschaftl. Stoffe, [3te Aufl.\ : Berlin, 1875, p. 175.) 



12. ALBUMINOIDS. The figures under this heading were obtained by multiplying by 6.25 the residue left on 

 deducting from the total nitrogen the nitrogen contained in the nicotine, ammonia, and nitric acid. 



13. MINERAL INGREDIENTS. The total percentage of mineral ingredients (ash) was determined by the method 

 of Schloesing, as described by Grandeau (op. cit., p. 6). The sample (10 grammes) was gently heated in a platinum 

 boat in a porcelain tube, through which a slow current of carbonic acid was conveyed, until combustible gases 

 ceased to be evolved. The combustion was then finished in a very slow current of oxygen, the tube being kept 

 below a visible red heat during the whole experiment. The ash thus obtained was of about the same consistence 

 as that of a cigar, 110 sign of fusion or " fritting" being observable, and was perfectly free from uuburned carbon. 



14. ASH ANALYSES. The ash analyses, the results of which are given in Table II, were made substantially by 

 the admirable method of Bunsen (Annalen der Oenologic, i, 3. See also Thorpe, Ann. d. CJiemie, cxlix, 163). The 

 phosphoric acid was separated from the insoluble ash by tin, as recommended by Bunsen, but the tin precipitate 

 was not further treated for the determination of the phosphoric acid, as the latter was directly determined by the 

 molybdate method of Finkener (Berichte d. dcutsch. Chem.' Gesellsch., xi, 1638), in the second portion of the insoluble 

 ash. The separations of potassium and sodium were made in duplicate, both by the platinic chloride and the 

 indirect (chlorine) methods. 



