M. TECHNOLOGY. 5 j 9 



through a triple one. He says that he has taken advantage 

 of this fact for a number of years by employing in quantita- 

 tive analyses a filter of heavy paper beneath the thin one of 

 Swedish paper. 15 (7, XXX., 170. 



NEW APPLICATION OF INFUSORIAL EARTH. 



Bottger publishes the observation that when an alcoholic 

 solution of any of the coal-tar colors is mixed with a suffi- 

 cient quantity of infusorial earth, water added, and the mixt- 

 ure filtered, the liquid will run ofl:' clear, while the earth 

 retains all the pigment. Hitherto the compounds of alumina 

 have been used for the production of the so-called lakes, and 

 it is quite probable that the above-noted behavior of this 

 material, which is veiy cheap, may find important applica- 

 tions in the arts. 



CONDENSING BEER FOR PRESERVATION. 



A patent for condensed beer has been taken out by Mr. 

 Lockwood. The liquid may be taken at any stage of fer- 

 mentation, although it is thought best to treat it when fit 

 for drinking. It is evaporated in a vacuum until a large 

 part of the water and alcohol is distilled away, and the beer 

 is reduced to a thick, viscid fluid of about the consistency of 

 molasses. The alcohol and water pass oft" in vapor, which 

 is condensed, and the alcohol subsequently obtained by re- 

 distillation is mixed with the condensed beer, either before 

 bottling or at any time afterward. In this way beer may 

 be reduced to one eighth or one twelfth its original bulk, 

 and it is said to keep for any length of time. To restore the 

 beer to its first consistency, it is only necessary to add the 

 bulk of water distilled off", with a small quantity of yeast 

 or other ferment, and in forty -eight hours the beer will 

 be ready for bottling. If charged with carbonic acid in a 

 siphon-bottle or receiver, the necessity of renewing the fer- 

 mentation is obviated. 18 A, XXII., 397. 



NEW FORM OF PAPER FILTER. 



Professor Stolba states that he has employed the following 

 form of paper filter for a long time in analytical determina- 

 tions, as well as for other purposes. He recommends it, 

 principally, on account of the comparatively small amount 



