52 
k? 
h(A-B=l,  2k(C—C)=0, —D-E)=0 
L 
—k(A+Bb)=0, —2h(C4+C) =r, — 3 (D+ £)= pv 
which may be satisfied by 
A+ B=0; D— K= 0, GC =D 
or 
2a' =i(a—Qd'+e), Ac’ =i(at+QW'+e), 2b = i(a—o). 
Thus (5) belongs to class III. 
In the same way it is seen that 
(6) is a special case of class II 
(8) belongs to class IV 
(10) is a special case of class III. 
The eleven equations given by Dvrac are therefore contained in 
the preceding 7 classes. 
Chemistry. — “On a few oxyhaloids.” By Prof. F. A. H. Scureine- 
MAKERS and Mr. J. MILIKAN. | 
Of the chlorides, bromides, and iodides of the alkaline earths 
several oxy-salts have already been described; in order to further 
investigate the occurrence or non-occurrence of these salts, to deter- 
mine the limits of concentration between which they exist and, if 
possible, to find other oxyhaloids, different isotherms have now been 
determined and by means of the ‘‘residue method” *) the compositions 
of the solid phases have been deduced therefrom. Here, we will 
discuss only the solid substances that can be in equilibrium with 
solution. : 
The system CaCl,—CaO—H, O. 
Temperature 10° and 25°. At both these temperatures occur, 
besides CaCl,.6H,O and Ca(OH),, as solid phases the oxychlorides: 
CaCl, .3 CaO .16H,O and CaCl, .CaO.2 H,0 
the composition of the second salt may be expressed also as: 
Ca OH . £H,0 
This latter oxychloride has already been found previously by a 
determination of the isotherm of 25°7); the first one was then 
1) F. A. H. ScHREINEMAKERS. Die heterogenen Gleichgewichte von H. W. BAKHUIS 
Roozepoom. Ille 149. 
*) I. A. H. SCHREINRMAKERS and Tu. rGee, Chem. Weekbl. 683 (1911). 
