508 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Galenite mixes readily with all ochres, and consequently 

 can be substituted for white-lead in painting in colors. With 

 oil it forms a mastic which can be employed without the use 

 of any other agent in cementing the joints of machines for 

 resisting the greatest pressure of air in water. It preserves 

 metals from oxidation with more energy than red-lead, and 

 may be employed equally with the latter in painting large 

 surfaces of metal. United with carbonate of lime and oil, it 

 forms mastics which, when spread over plaster with the 

 knife, acquire great hardness, and after being sand-papered 

 assume the smoothness and polish of marble. The Abbe also 

 claims that the results of experiments give promise that it 

 will be especially serviceable in painting such portions of the 

 wood or metal surface of vessels as are submerged in water, 

 adhering to them with great tenacity, and probably prevent- 

 ing the adhesion of barnacles, oysters, etc., or the attacks of 

 the teredo. The precise method of manufacturing this new 

 and important substance is not stated. It has, however, been 

 lately patented by its inventor, M. Jules David. 3 B, June 

 25,1874,284. 



VARNISH FOR ALCOHOL CASKS. 



Varnishing the interior of clean, dry casks with the follow- 

 ing preparation is said to close the crevices and pores of the 

 wood, and to render them perfectly tight for alcohol, as the 

 material oxidizes soon after drying, and becomes insoluble 

 in alcohol, and does not scale off: Dissolve two pounds of 

 leather clippings (best, finely chipped, and previously boiled 

 in water) in two ounces of oxalic acid and four pounds of 

 water, on a water-bath, with continued stirring, care being 

 taken not to prolong the operation more than necessary, and 

 dilute the solution gradually with six pounds of warm water. 

 9 C, February, 1874, 28. 



VARNISH AFFORDING A DEAD SURFACE ON DRYING. 



Varnishes that leave a dead surface on drying, capable of 

 substitution for ground glass, as for glass stereographs, and 

 of use in retouching negatives, may be made by mixing so- 

 lutions of resins with liquids in which they are insoluble. A 

 solution of sandarach resin in ether, when mixed with one 

 fourth as much benzole, affords an excellent imitation of 



