956 Transactions of the American Institute. 



which penetrated to the depth of 2,394 feet, gave an increase of 

 one degree Fahrenheit for every fifty-seven feet. 



UTILIZATION OF SEWAGE. 



An experiment is now being made at Asnieres, near Paris, on a 

 field of about two and a half acres in extent, and situated about 

 three hundred yards from the mouth of the great sewer .sink. Two 

 portable steam engines pump five hundred cubic meters of sewage 

 water into a receptacle at one end of the field. A part of the 

 liquid is applied directly to various crops, and the remainder is 

 treated with chemical agents for its purification and conversion 

 into valuable compounds. M. le Chatelier has expressed the opinion 

 that the cultivated lands around Paris can never absorb a conside- 

 rable portion of the sewage water, because, first, the land is divided 

 into small allotments, which increase the cost of distribution; 

 second, the principal arable lands lie on high plateaux sloping con- 

 trary to the direction of the streams, and great difliculty would be 

 found in getting rid of the excess of water by drainage. 



COLORLESS DRYING OIL. 



Mulder finds that by boiling linseed oil for two hours with three 

 per cent of red lead, and after filtering, exposing it in shallow 

 vessels to sun-light and a current of air, a good colorless drying 

 oil is produced. 



BARYTA WHITE. 



Barytes, if ever so white, will not make so permanent a white 

 paint as sulphate of baryta prepared artificially. Kuhlmann & 

 Wagner's process is as follows: The native sulphate is at first 

 reduced to sulphide of barium by calcining, in iron crucibles, four 

 parts, ground to a fine powder, with one part of powdered coal, 

 and from five to eight per cent of coal tar. After the process has 

 continued for several hours, the mixture is removed from the cruci- 

 bles and recalcined in a closed furnace to prevent any oxidation. 

 When cold it is treated with hydrochloric acid, the liquid being 

 kept alkaline to prevent the admission of other metals, and from 

 the chloride of barium thus obtained, by means of sulphuric acid, 

 is precipitated the jDermanent white. 



In relation to the last two items read by the Chairman, Dr. 

 J^ euchtwanger remarked that linseed oil when bleached, will not 

 change its color from any action of itself; but when with white 

 lead, the compound is changed in color by sulphuretted hydrogen. 



