K. DOMESTIC AND HOUSEHOLD ECONOMY. 453 



then to be inverted over a few drops of aqua ammonia on a 

 plate. In a few minutes most blue, violet, and crimson flow- 

 ers change to beautiful green, dark crimson to black or dark 

 violet, and white to yellowish. If they are then immediate- 

 ly placed in fresh water, they will retain their new color from 

 two to six hours, according to the amount of ammonia taken 

 up, but will gradually regain their original tints. The cus- 

 tomary way of treating blue, violet, and red asters for winter 

 bouquets with nitric acid gives irregular results, on account 

 of the wax on the leaves, and it is preferable to expose them 

 to the fumes of hydrochloric acid, by hanging them, tied in 

 pairs by their stems, heads downward on strings drawn across 

 the interior of a close wooden box, upon the bottom of which 

 are several pjates with hydrochloric acid, and with two glass 

 windows, on opposite sides, through which the progress of 

 the coloration may be noticed, so that the flowers may be re- 

 moved as they acquire the desired tints, and hung in the 

 same manner in airy, shady rooms to dry. They should be 

 preserved in a dry, dark place. 5 (7, 1873, xxx., 238. 



REGENERATION OF OIL-PAINTINGS. 



Besides the irremediable darkening of oil-paintings by age, 

 they are also liable to deterioration by the cracking of the 

 paint on severe drying, and also to the loss of brilliancy by 

 the formation of numberless small fissures in the originally 

 transparent, heavy film of varnish upon them. The former 

 defect can only be removed by the tedious filling of the 

 cracks with fresh paint. As a means for remedying the lat- 

 ter, Dr.Weigelt suggests, as an improvement on a plan pro- 

 posed by Pettenkofer, that the varnish be partially dissolved 

 (and the fissures thus filled up) by leading upon the picture, 

 through a gum tube, a blast of air which is saturated with 

 alcohol, by blowing it, by means of a bellows, through a flask 

 containing alcohol gently warmed. 15 C, ix., 129. 



FIG COFFEE. 



A coffee substitute, of roasted figs, has been in the market 

 in Austria for ten years, and is also prepared at present in 

 Berlin. Recent careful tests of it indicate that it possesses 

 a more agreeable flavor than the chiccory substitute, and that 

 it has thus far been brought into the market free from inju- 



