452 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



mice. Its lightness is also a great recommendation. One 

 cubic foot of it weighs 21^ to 26 pounds ; the same bulk of 

 dry coal-ashes, 40-J- to 42-J- pounds ; and of dry earth, 94 to 

 128 pounds. For casing steam-pipes it is mixed with boiled 

 flaxseed. 13 C,Jime 1,1873,108. 



PROCESS FOE BENDING GLASS TUBES. 



The JPolytechnisches JVotizblatt calls attention to the fact 

 that a perfectly round bend of any curvature may be given 

 to glass tubes if they are filled with fine dry sand and closed 

 at both ends when heated for bending, as by a Bunsen burn- 

 er. A similar plan is available with copper and lead tubes. 

 15 C, xviii., 286. 



POWDERED GUM ARABIC. 



According to Dr. Hagar, gum arabic, under prolonged dry- 

 ing, preliminary to pulverization, not only experiences a loss 

 of natural moisture (as high as ten per cent.), but also a 

 slight change of properties, as indicated by its power of re- 

 ducing, at a gentle heat, potassic solution of copper. After a 

 time it also loses its ready solubility in water, and conse- 

 quently oily emulsions are not as easily made with it. Ha- 

 gar therefore advises that gum arabic be kept only as a mod- 

 erately fine powder, and that in moist or cold weather it be 

 dried no longer than one day in a warm place (about 80), 

 in which case it will lose but two per cent., or at most two 

 and a half per cent, of its weight. Rep. of Alexander Sehultz, 

 Vienna Ex., 1873, 40. 



KEEPING FLOWERS FRESH. 



According to a communication addressed to the Agricult- 

 ural Society of Paris, cut flowers may be kept fresh, for from 

 fifteen days to a month, by inserting their stems in water in 

 which sal ammoniac or ammonia chloride has been dissolved 

 in the proportion of seventy-five grains to the quart. 3 B, 

 December 25, 1873, 715. 



RETAINING THE NATURAL COLORS OF DRIED FLOWERS. 



Puscher recommends sticking the stems in the neck of a 

 glass funnel, leaving the flowers in the wide portion, but 

 leaving about an inch from the top unfilled. The funnel is 



