628 Transactions of the American Institute. 



parts of rosin with one part of caustic soda and five parts of water, 

 which is mixed with one half its weight of phistcr of paris. This 

 cement has great adhesive power, and is not permeable by petro- 

 leum; it sets firmly in less than an hour, and is a veiy slow conduc- 

 tor of heat. Zinc white, white lead, or precipitated chalk may be 

 substituted for plaster of paris, but the material will be longer in 

 hardening. 



GEOLOGY OF CHINA AND JAPAN. 



Mr. Raphael Pumpelly furnishes in paper 202, of the Smithsonian 

 Contributions to Knowledge, the results of his explorations in China 

 and Japan He states that the Sinian elevation is the extensive N. 

 E. and S. W. system of upheaval, which is traceable through nearly 

 all Eastern Asia, and to which this portion of the continent owes its 

 most salient features. There is a striking analogy between the 

 Sinian and our Appalachian range as regards structure, strike and 

 dip, and what is more remarkable, the elevation of each has deter- 

 mined the eastern boundary of a vast continent. 



SPONTANEOUS CHANGE IN GLASS. 



About a year ago Mr. Newell, of Philadelphia, constructed a 

 photographic wagon, like those seen in many small villages which 

 cannot furnish business for a permanent establishment. To light a 

 j)art of it he used orange-colored glass, on account of its being 

 impermeable to the violet or actinic rays. After some time he 

 found himself troubled with what are technically called " foggy 

 plates; " on substituting orange-muslin for orange-glass, the fog 

 vanished from the plates, and on examining the glass it was found 

 to have materially changed in color. Similar changes in glass have 

 noticed by others. 



TAR LIQUOR. 



M. E. Guj'ot exhibits specimens of this popular pharmaceutical 

 preparation at the Paris Exposition. It is made by heating in dis- 

 tilling apparatus, in a sand bath, eleven kilogrammes of tai' from 

 Norway, one of carbonate of soda, and twenty litres of water. He 

 then adds to the liquor, which has not passed over the still, suflScient 

 water to produce forty litres of liquid. After being allowed to 

 settle, the clear part is poured into a barrel, and the volatile por- 

 tions obtained are then added. The whole is well stirred for some 

 minutes, and after standing for several days it is filtered. The 

 result is a dark brown liquor, of strong aromatic taste, which is 

 mixed with water to form tar water. One ounce contains one grain 

 of resinous matter. 



