426 C. E. Linebarger — Molecular Masses of Dextrine, etc. 



material dissolved in hydrochloric acid, which has been sub- 

 jected to prolonged heating, afforded Dr. "Weinsehenk the fol- 

 lowing results : 



Fe 83-02 



Ni 16-22 



Go 1-63 



P o-oo 



100-87 



The above analysis would place this iron near the " Cape 

 Iron Group." As the physical properties of this group of irons 

 have been so little studied, it is impossible for us to say whether 

 the structure coincides or not. The complete absence of phos- 

 phoric acid, of which not a trace could be detected, indicates 

 that this meteorite is an exception to the general rule in not 

 containing the characteristic phosphor-nickel iron. To the 

 best of our knowledge the occurrence of an iron in this group 

 from Chile is new. It represents a new type, and possesses 

 none of the many characteristics of the other known Chilean 

 meteorites. 



Akt. LY. — The Molecular Masses of Dextrine and Gum 

 Arabic as determined by their Osmotic Pressures ; by 



C. E LlXEBARGER. 



Pfeffer's Osmotische Untersuchungen* have furnished 

 until now the principal experimental support for Yan 't Hoff's 

 theory of solutions. The measurements of the osmotic pres- 

 sures of cane sugar solutions agree as well as could be desired 

 with the deductions from the theory. The monograph con- 

 tains, however, the measurements of the osmotic pressures of 

 several other compounds, such as saltpeter, potassium sulphate, 

 cream of tartar, gum arabic and dextrine, and these determina- 

 tions have been carried out with so much care and painstaking 

 that considerable reliance may be placed on the accuracy of 

 the results. As far as I know, no particular attention has 

 been paid to these results. Yet the determinations of the 

 osmotic pressures of dextrine and gum arabic afford a means 

 for ascertaining their molecular masses. It is well established 

 that dextrine has the formula (C 6 H 10 OJ m , and gum arabic is 

 regarded as a salt resulting from the combination of several 

 bases, as potassium, calcium and magnesium, with an acid 



* Leipsic, 1877. 



