244 51 Poioers — Explosive Ejectamenta of Kilauea. 



the sink, and by coarse ejectamenta over the ash ; the younger, 

 belonging to the 1789 eruption, consisting of thread-lace scoria, 

 ash and bombs. The age of the older deposit is uncertain, but 

 evidence is given favoring the view that it may be older than 

 the present sink. 



Thread-lace scoria, a variety of basaltic pumice, is found to 

 be a peculiar kind of gaseous lava-froth which has been blown 

 out of craters and not formed in situ on the surface of pahoe- 

 hoe flows. It appears to represent the extreme phase of 

 gaseous pumice where the vesicles are separated by only 

 slender threads instead of by walls. 



Troy, N. Y., 



December 9, 1915. 



Aet. XIII. — Succinic Acid as a Standard ; by C. A. Peters 

 and V. Sauchelli. 



Phelps and Hubbard* have stated that succinic acid may be 

 used as a standard for volumetric work against ammonium 

 hydroxid with cochineal as an indicator. The statement of 

 Phelps being contrary to the experience of one of the authors, 

 the standard of ammonia against succinic acid under conditions 

 as outlined by Phelps and Hubbard was determined again, and 

 compared with that obtained electro-titrametrieally according 

 to van Suchtelen and Itano.f We were unable to duplicate 

 the work of Phelps and Hubbard relating to the comparison of 

 ammonia and succinic acid. 



Preparation of Succinic Acid. — The succinic acid was pre- 

 pared according to one of the methods given by Phelps and 

 Hubbard, it being dissolved in boiling distilled water and then 

 allowed to crystallize. The first crystals were washed with 

 water and recrystallized. They were then dried on filter paper 

 in the air, and kept in a desiccator over sulphuric acid. 



The melting point of the purified succinic acid determined 

 in an open capillary tube was lSS^O C. The thermometer 

 used was calibrated and corrected for steam exposure. 



Apparatus. 



Conductivity Cup. — As the ordinary Ostwald type of cell 

 does not allow convenient thorough mixing of solutions, the 



* This Journal (4), xxii, 211, 1907. 



f Jour. Amer. Chern. Soc, xxxvi, 1793, 1914. 



