KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 
TE AMSTERDAM, 
PROCEEDINGS OF THE MEETING 
of Saturday February 22, 1902. 
DGG 
(Translated from: Verslag van de gewone vergadering der Wis- en Natuurkundige 
Afdeeling van Zaterdag 22 Februari 1902, Dl. X). 
Contents: “On pentanitrophenylmethylnitramine and tetra- and pentanitrophenol”. By Dr.J. J. 
BLANKsMA. (Communicated by Prof. C. A. Lopry pe Bruyn), p. 437. — “On the 
development of the entoderm, of Kuprrer’s vesicle of the mesoderm of the head and of the 
infundibulum in Muraenoïds”. By Dr. J. Borke (Communicated by Prof. T. PLACE), 
p. 442. — “Ternary systems” (1). By Prof. J.D. van DER WAALS, p. 448. — “Examination 
of specimens of sand from borings done at the works of the outer harbour at Sche- 
veningen”. By J. A. GRUTTERINK. (Communicated by Prof. J. L. C. SCHROEDER VAN DER 
Kork), p. 464, (with one plate). — “The relation between the brightness of a luminous 
point and the moments at which we observe its sudden appearance or disappearance”. 
By Prof. H. G. van DE SANDE BAKHUYZEN, p. 465. — “A new law concerning the 
relation of stimulus and effect” (III). By Prof. J. K. A. WerRTHEIM SALOMONSON. 
(Communicated by Prof. C. Winker), p. 469. — “The physiological Bacteriology 
of the intestinal canal (2nd abridged paper. The bacteriological relations in the 
intestinal canal of the rabbit)”, By Dr. ALex Kier. (Communicated by Prof. T. 
Prace), p. 477. — “On the motion of variable systems”. By Prof. J. CARDINAAL, 
p. 489. — “On the measurement of very low temperatures. IV. Comparison of the 
platinum thermometer with the hydrogen thermometer”. By B. Merrink, (Communi- 
cated by Prof. H. KAMERLINGH ONNES), p. 495, (with one plate). — “Factorisation of 
large numbers” (III), By F. J. Vars. (Communicated by Prof. P. H. Scnours), 
p. 501. 
The following papers were read: 
Chemistry. — “On pentanitrophenylmethylnitramine and tetra- 
and pentanitrophenol.” By Dr. J. J. BLANKSMA. (Communi- 
cated by Prof. C. A. Lopry DE BRUYN). 
(Communicated in the meeting of December 28, 1991). 
It has been known for a long time that aniline and phenol are 
very readily converted into trihalogen substitutionproducts by treat- 
ment with chlorine- and bromine-water and also that trinitrophenol 
(pierie acid) may he readily obtained from phenol by the action of 
29- 
Proceedings Royal Acad. Amsterdam. Vol. LV. 
