KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 
TE AMSTERDAM, 
PROCEEDINGS OF THE MEETING 
of Saturday February 24, 1900. 
2G 
(Translated from: Verslag van de gewone vergadering der Wis- en Natuurkundige 
Afdeeling van Zaterdag 24 Februari 1900 Dl. VIII). 
Contents: “A simple and rapid method for preparing neutral Pikro-carmine”. By Prof Joa: 
VAN Wine, p. 409. — “The Entropy of Radiation” (II). By J.D.van per Waars Jr. 
fCommunicaied by Prof. H. G. van DE SANDE BAKHUYZEN), p. 413. — “On rational 
twisted Curves”. By Prof. P. H. Scroure, p. 421. — “Lipolytic ferment in Ascites-liquid 
of man”. By Dr. H. J. HAMBURGER, p. 428. — “Methods and Apparatus used in the 
Cryogenic Laboratory. IT: Mercury pump for compressing pure and costly gases under 
high pressure”. By Prof. H. KAMERLINGH Onnxs (with 7 plates), p. 437. — “The alleged 
identity of red and yellow mercuric oxide” (Part II). By Dr. Ernst Conen (Commu- 
nicated by Prof. H. W. Baxuvis RoozeBoom), p. 458. — Prof. A. P. N. FRANCHIMONT 
presents Dr, P. J. Montacne’s dissertation: “The action of hydrogen nitrate upon the 
three isomeric chloro-benzoic acids and some of their derivatives”, p. 461. — “The 
Enantiotropy of Tin” (IV). By Dr. Dr. Ernst Conen (Communicated by Prof. H. W. 
Baxknuis RoozEBoom), p. 464 (with one plate). — “On Phenomena on the sun con- 
sidered in connection with anomalous dispersion of light”. By Prof. W. H. Juuius, 
p. 467. — “On the formation of trisubstituents of benzol form disubstituents”. By 
Prof. A. F. HorLEMAN (Communicated by Prof. C. A. Lopry DE Bruyn), p. 468. — 
“Enquiries into the system Tl1NO,;+AgNO,”. By Dr. C. van Erk (Communicated 
by Prof. H. W. Bakuuis RoozeBoom), p. 468. 
The following papers were read: 
Anatomy. — Prof. J. W. van Wing describes: “A simple and 
rapid method for preparing neutral Pikro-carmine’’. 
By many it will no doubt be deemed unnecessary trouble to add 
another to the manifold prescriptions for the preparation of pikro- 
carmine. Most investigators who use it, will be content with one 
of the well-known methods of preparation which they have been 
in the habit of following, as was also the case with me, until, 
about a year ago, the stain disappointed me. 
This happened during the study of young embryonic tissue, which 
had been blackened by osmic acid and had afterwards been bleached. 
30 
Proceedings Royal Acad, Amsterdam. Vol. II. 
