ESTIMATIOS O F TELLTRICM I N COPPER R T L L I O X .
280
A good sample for nitroglycerol purposes tested as fol!on-s : ash, trace ; car?miaceous residue. 0 . 0 1 2 per ceiit. ; sodium chloride, 0 . 0 0 2 per ceiit. : total acid equivalent, O . O j g 4 ; : pernianent specific gravity, 1 . 2 6 j 3 ; specific gravity, 1.2634 : higher fatty acids, none ; reaction, neutral. I alii iiidebted to Dr. Joseph I r a n Ruymbeke, the inventor of the Van Ruyiiibeke process Of recovering glycerol froiii soapl j ~ s for , tlie first idea of the total acid equivalent and perniaiient specific grav it!. determinations. Till
~ 0 1 . 1 ~ \ 1 1 ~ 1 .~\ ~- s l v l ~ R s I l ~ ,
I)ecellll,er I;,
l%l.
ESTInATION OF TELLURlUil IN COPPER BULLION.' BY C A B E L L U'rIrrc11F:Au.
D
ISSOLVE from twenty-five to fifty grams of the bullion in
nitric acid 3 2 " B. and boil off tile excess of acid. Add to this solution ail aiiiount of a ferric nitrate solution equivalent to 2 j 0 nigms. of metallic iron. Precipitate, while hot, with an excess of ammonia, filter, aiid wash with dilute aniiiionia until tlie copper salts are entirely removed, redissolving and reprecipitatiiig i f necessary. T h e residue o r i the filter contailis the tellu1-iuiii aiiti scleniuni present i i i the Lullioii as ferric tellurites aiid selenites. This is dissolved in hydrochloric acid, and excess of tartaric acid added, tlic solution made alkaline with potassium hydroxide, and hgdrogeii sulphide passed tlirough it, when the tellurium aiid selenium pass into solution as soluble sulphides. Filter ; decoinpose the alkalitie sulphides in the filtrate with dilute hytlrocliloric acid ; allow the liquid to stand in a xariii place until the h>.drogeii sulphide has been reiiiovctl. Filter agairi ; dissolve tlie tellurium arid seleriiurii sulphitles in aqua regia ; evaporate the solution to dryness, take up wit11 hydrochloric acid and precipitate the telluriuiii and seleniuiii froin the solution by passing sulphur dioxide through to saturation. Cover tlie beaker and alloiv the solution to stand for tivelve hours in a warm place, ivlien the precipitate, which consists of tellurium and seleiiiuiii, is filtered on a tareti filter, drictl at IOO', arid weighed together. 1
K c a d ;kt t h e Hoston Xeetitig, l k c e i i l b e r
27, I - C , ~ ,
THE USE O F SULPHUROUS ACID I N , ETC.
2SI
T h e selenium is separated from the tellurium by boiling the precipitate in concentrated potassium cyanide solution, filtering, and adding hydrochloric acid, when the selenium collies down as a brick-red precipitate, which is weighed as before, after drying a t I 00". T h e telluriuin is determined by difference or the small amount dissolved by the cyanide solution may be precipitated, after removal of selenium, by saturating with sulphur dioxide, collecting the precipitate with the original residue. and weighing after drying at 100'. THECOLEJIRIANUSWERSITY, WASHISOTON. D. C.
T H E U S E OF SULPHUROUS ACID (HNaSO,) IN rlANUFACTURE OF GLUCOSE SYRUP A N D GRAPESUGAR. BY
HOR.4CE
E. HORTOH.
Recelled January 1 8 , ' 8 9 5 .
U
P to the year 1893 a large quantity of the glucose syrup and grape-sugar offered in home markets was manufactured by a carefully worked-out process, in which sulphurous acid had but little if any place. While a fine grade of glucose can be manufactured without the use of sulphurous acid, its irrational use has taken full possession of some manufacturers. T h a t sulphurous acid has a legitimate place in a rational process of manufacture few who have studied the subject will deny, but a great deal of careful work is yet necessarjr to define the use of this reagent. I have studied the action of sodiuin bisulphite on glucose syrup and grape-sugar in several directions, and with interesting results. T h e bisulphite used was manufactured by Gelian and Co., of New Uork, who have an excellent article of 38"-40" Be. density . Pycserzdng CoZor of Ghcose Syvzq3s.--Numerous experiments have convinced ine that sulphurous acid is of great value ill preserving the color of glucose syrups. I will present here one
