620 
Hence : 
If 
(Doon An RT log — : 
and therefore, if we may again put 
(Ci = RT log V+ RT + RT log (1 — B) 
for (w,)Vv,4, also when there is no equilibrium at the degree of asso- 
ciation £,, finally : 
Gi k= ee RT logv, + RT + RT log (1 — B). - (24) 
quite identical with (1d). |For (v)ro,e, may namely be written §.,3,, 
because v,,3, represents a state of equilibrium, and hence c= 
(see above) |. 
This way, which is much shorter than the preceding, and there- 
fore the prevalent one, leads therefore — in spite of (t,)v,z, being 
changed into its value, if the mixture 8, is considered as an arbi- 
trary one, i. e. apart from the presence or absence of internal equi- 
librium between the reacting components — to the perfectly accu- 
rate expression, which we have found in (1¢) by the much more 
lengthy but perfectly unobjectionable’ way. 
Baarn, Oct. 21, 1912. 
Botany. — Vhe Linnean method of describing anatomical structures. 
Some remarks concerning the paper of Mrs. Dr. Marit C. Stops, 
entitled : ““Petrifactions of the earliest Huropean Angiosperms.” 
J. W. Mout and H. H. Janssonius. 
In our “Mikrographie des Holzes der auf Java vorkommenden 
Baumarten’”” we are trying to show that important results in systematic 
Botany can be obtained by anatomical investigations concerning the 
wood, if these are conducted with sufficient care. For this purpose 
descriptions of the anatomical structure are necessary, made with 
careful observance of the rules given by LiNNÉ for describing the 
external appearance of plants. Of course some additions to these rules 
and some alterations have been necessary, because anatomical and 
morphological facts belong to somewhat different orders of things 
and because the microscopic method presents peculiar difficulties. 
But in the main it is the Linnean method we apply. 
The results obtained in the two first volumes of our work are 
from a systematic point of view most satisfactory, which we hope 
will become still more apparent, when after some years the work 
will be finished. Families, genera and in many cases even species 
