520 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



of ash, where small quantities are to be determined, since 

 but little more than half as much paper is employed. Al- 

 though less water is used for washing, the filtration is some- 

 what slower, since it does not fit the walls of the funnel so 

 closely. The paper is simply folded once in the middle, and 

 the one end then closed by a sharp narrow fold, formed by 

 lapping the paper several times, each time rubbing the fold 

 with a paper-knife or agate pestle. It is then rounded, like 

 an ordinary filter, placed in the funnel dry, and moistened, 

 and the fold pressed against the funnel with a glass rod. 

 He suggests that other materials besides paper might be 

 used, and that collodion, or some other cement, might be 

 used instead of the repeated folding. 14 C, CCXVL, 445. 



AXOTIIER DIRECT SODA PROCESS. 



Herr Viedt has ventured the opinion that common salt 

 may be converted into caustic soda by the simple action of 

 steam at high temperatures. The chemical changes involved 

 in the process would be simply the production of caustic 

 soda and hydrochloric acid, which last, being gaseous, could 

 readily be removed. The experiments he has undertaken 

 upon this subject have, however, only met with partial suc- 

 cess, possibly because of imperfect apparatus. Should his 

 expectations be realized in future experiments, a material 

 advance in the alkali manufacture would result. 



PREPARATIOX OF BLOOD AS A POWDER. 



Mr. Le Bon says if blood be evaporated under diminished 

 pressure at the temperature of the body, in a certain appa- 

 ratus, it will be obtained as a powder soluble in water or 

 in an acid solution of pepsin, and showing the characteristic 

 absorption-bands of haemoglobin, which constitutes eighty- 

 six per cent, of the corpuscles. This method is suggested 

 by the author for the utilization of the blood for food or for 

 other purposes. 21 A, February^ 280. 



AIR-TIGHT J0I:NTS. 



Professor Crookes states that in some observations made by 

 him it has been necessary to preserve hi^ apparatus within 

 a vacuum for a number of hours, and, if possible, days. To 

 this end it was very important to secure a cement that would 



