124 



CHEMISTRY. 



same way that Schmitz and Nessler had, and 

 concluded that the un fermentable residues from 

 potato-sugar were not at all objectionable. 



Dr. J. R. Duggan, of Johns Hopkins Univer- 

 sity, has performed special experiments on the 

 fermented products of corn-starch sugar, which 

 he continued through two -months, swallowing 

 frequent large doses of various extracts. Dur- 

 ing this time he felt nothing that indicated that 

 the extracts contained anything injurious. 



As regards the action of sunlight or diffused 

 daylight upon colors fixed in dyeing, M. De- 

 caux has proved by a long series of compara- 

 tive experiments that the shades dyed upon wool 

 in the vat, with Prussian blue, cochineal, mad- 

 der, weld, and fustic, are much more perma- 

 nent than those obtained with Nicholson blue, 

 magenta, jaune d'or, and picric acid. Four of 

 the coal-tar colors differ from the rest of their 

 class as regards stability. They are the pon- 

 ceau, called naphthol carmine, orange No. 2, 

 chrysoine, and artificial alizarin. Colors for 

 painting in water and oils are divided into the 

 absolutely permanent, the moderately perma- 

 nent, and the fugitive. If used with water, all 

 the most beautiful reds, carmine, carmine-lake, 

 most madder-lakes, and vermilion, fall under 

 the fugitive class. If mixed with oil, the mad- 

 der takes rank as moderately permanent. The 

 action of the arc electric light is similar to that 

 of the sun, but it has only one fourth of the 

 power. 



Several instances have been reported of the 

 decomposition of explosive gelatine on keeping, 

 or after exposure to moderate temperatures. 

 Gen. H. L. Abbott mentions the decay during 

 the winter and spring of 1881-'82 of the sam- 

 ples of this substance that remained on hand 

 after the experiments of the former year in 

 submarine mines, the gelatine separating into 

 cellulose and free nitro-glycerine, with copious 

 evolutions of nitrous fumes. Mr. Charles E. 

 Munroe has observed the decomposition of a 

 package of camphorated explosive gelatine in a 

 room of fairly even temperature and dryness, 

 after more than a year's exposure. It was ob- 

 served to be giving off nitrous fumes; the 

 outside of the paper containing it was covered 

 with a congeries of fine crystals, while the 

 odor of camphor was still quite strong. The 

 mass was friable in water, and disintegrated 

 after a short immersion. The camphor odor 

 shortly disappeared, the water became of a 

 straw-color, and showed traces of nitrous, but 

 no nitric acid. Oxalic acid crystallized out in 

 quantity on evaporation of the filtered liquid, 

 and a sugar-like mass, giving the glucose re- 

 action with Fehling's solution, was obtained 

 on evaporation of the "mother-liquor." The 

 paraffine was regained unchanged, and the 

 paper was recovered in a flocculent condition, 

 with the color bleached. No glycerine, nitro- 

 glycerine, or gun-cotton was detected. 



Experiments by E. J. Mills and A. G. Ren- 

 nie with purified Cashmere wool and a 0*02- 

 per-cent. solution of rosaniline acetate showed 



that the maximum dyeing effect was produced 

 at the temperature of 31 '1 C., the minimum 

 of effects being at 1'46 and +81-15. Using 

 the rosaniline salt in excess, the maximum 

 deposition of color occurred at 39 C., and the 

 minima at about and at 82. With mauve- 

 ine the maximum was at about 49 C., and the 

 minimum was calculated on one side as 23'8 

 C., while on the other side it was not reached 

 at 85 C., though the diminution was marked. 

 The conclusion was reached that where an ani- 

 line color is susceptible of dissociation there is 

 positive disadvantage in using high tempera- 

 tures in the dye-bath. 



Arthur H. Elliott, of the Columbia College 

 School of Mines, has made some satisfactory 

 experiments in the derivation of anthracene 

 from water-gas tar. Two series of experi- 

 ments made it evident that this tar is particu- 

 larly rich in anthracene, the second series giv- 

 ing 2'63 as the total percentage in the original 

 tar. This is equivalent to four or five times 

 the amount contained in ordinary coal-tar, that 

 being given at 0'3 to 0'4 per cent. These ex- 

 periments assume importance in view of the 

 facts that anthracene is the most valuable of 

 the higher members of the aromatic hydro- 

 carbons, on account of its use in the production 

 of alizarine, and that water-gas is destined to 

 be used more extensively in the United States 

 than it now is. 



A. Remont has described a process for the 

 determination of the wool, silk, and cotton in 

 tissues. Four portions of the cloth are taken, 

 of equal weight. One part is put aside, and 

 the other three parts are boiled in hydrochloric 

 acid for the removal of the dyes and weighting 

 matters. One of the boiled swatches is laid 

 aside, and the other two are exposed in a 

 boiling solution of basic zinc chloride, drained, 

 washed, and dried, for the removal of the silk. 

 One of these two swatches is then laid aside, 

 while the other is boiled for a quarter of an 

 hour in soda-lye. All the four swatches are 

 then heated for fifteen minutes in distilled 

 water, pressed, and allowed to lie in the same 

 room in which they had been previously kept. 

 The next day they are weighed. The differ- 

 ence in the weight of the swatch first laid aside 

 and that of the second swatch represents the 

 dressing, that between the second and the 

 third gives the silk, and the weight of the 

 fourth swatch represents approximately the 

 vegetable fiber present, although it has suf- 

 fered some loss amounting possibly in the 

 case of cotton to 5 per cent. from the action of 

 the soda. Multiplying the figures by 50, we 

 obtain the percentage of dressing, silk, and 

 vegetable fiber. The remainder is the wool. 



A. Livache uses manganese to accelerate the 

 drying of oils. He finds that while an ordina- 

 ry drying oil containing lead dries in twenty- 

 four hours, a similar oil containing manganese 

 dries under the same conditions in from five to 

 six hours. Copper, zinc, cobalt, nickel, iron, 

 chrome, etc., prolong the time of drying to from 



