May 13, 1904.] 



SCIENCE. 



759 



per liter to about 1.42 gms. CaSO^ per liter 

 in a solution containing about 15 gms. K^SO^ 

 per liter, and then gradually rises to 1.585 gms. 

 per liter in a solution containing 32 gms. 

 K.SO^ per liter. This latter point is a triple 

 point where a new solid phase syngenite 

 (CaSO/KjSO/HjO) separates. As the con- 

 centration with respect to potassium sulphate 

 still increases, no gypsum remains as solid 

 phase but only syngenite, the amount of 

 calcium sulphate in solution steadily decreas- 

 ing. The solubility curves were determined, 

 starting both with gypsum and with syngenite, 

 good agreements being obtained. The posi- 

 tion of the triple point was redetermined by 

 the authors by using the procedure of van't 

 Hoff and Wilson who had found a somewhat 

 higher concentration with respect to calcium 

 sulphate. The results confirm those obtained 

 by extrapolation on the solubility curve. The 

 solubility curve for calcium sulphate and 

 sodium sulphate previously determined at 25° 

 C. by Cameron and Seidell was confirmed. 

 It is similar to the calcium sulphate, potassium 

 sulphate curve, but there is no separation of a 

 double salt at the temperature employed. 



The last paper on the program, entitled 

 ' Ammonium Chloride as a Reagent for Indi- 

 cating Dissociation,' was presented by Dr. 

 Peter Fireman. 



In a former communication the author 

 showed that when antimony pentachloride and 

 ammonium chloride are heated in a sealed 

 tube they act upon one another according to 

 this equation : 



SSbCls -t- 2NH,C1 = 3SbCl3 + 8HC1 + N„ 

 while tin tetrachloride and titanium tetra- 

 chloride remain unchanged when similarly 

 treated with sal ammoniac. The different 

 behavior of the chlorides was ascribed to the 

 fact that antimonic chloride readily dissociates 

 on heating while the other two metallic 

 chlorides do not. 



In his new communication he gave the re- 

 sults of experiments by which he tested the 

 validity of this explanation. The hypothesis 

 was fully corroborated. He found that ferric 

 chloride and cupric chloride which are knovm 

 to dissociate behave like antimonic chloride, 

 the reaction being: 



and 



3FeCl3 + NH4CI = SFeCL + 4HC1 + N 

 3CuCL + NH,C1 = BCuCl + 4HG1 + N, 



while mercuric chloride, a non-dissociating 

 halide remains unchanged like stannic chloride 

 or titanium tetrachloride. 



A. Seidell, 

 Secretary. 



THE SCIENCE CLUB OF THE UNIVERSITY OF 

 MISSISSIPPI. 



The regular monthly meeting of the club 

 was held April 15, 1904, in the chemical lec- 

 ture room. The leader for the evening. Pro- 

 fessor R. W. Jones, presented ' Some Thoughts 

 in Reference to the Water Supplies of Missis- 

 sippi.' A brief account of the history of water 

 analysis was given, showing that, while in 

 earlier years stress was laid upon the mineral 

 ingredients, to-day the emphasis is placed 

 upon the organic and sanitary analyses. In 

 passing, the fact was noted that the value of 

 mineral springs had long been greatly exag- 

 gerated. The Michigan standard of the purity 

 of drinliing water was discussed by the lecturer. 

 The speaker then called attention to some in- 

 teresting and valuable results of his own 

 analyses of water from deep wells, artesian 

 wells and streams throughout the state. 

 Special reference was made to the geological 

 formations of the middle-eastern section of 

 the state, affording four different water- 

 horizons, each yielding water of excellent 

 quality. Alfred Hume, 



Secretary. 



THE SCIENCE CLUB OF UNIVERSITY OF WISCONSIN. 



The sixth meeting of the club for the year 

 was held Tuesday, March 22, in the physical 

 lecture room of Science Hall. The first paper 

 of the evening was by R. A. Harper on ' The 

 Organization of the Cell as shown in Certain 

 Mildews.' The paper discussed the develop- 

 ment of the fruiting bodies of certain mildews 

 from the standpoint of the structure and be- 

 havior of their nuclei in both fusing and divid- 

 ing cells. A permanent polar organization of 

 the nucleus and continuous connection of 

 chromation and central body are found in these 

 fungi. 



