DECEMBER 29, 1899. ] 
THE ACADEMY OF SCIENCE OF ST. LOUIS. 
AT the meeting of the Academy of Science of 
St. Louis of December 4, 1899, the following 
subjects were presented : 
Dr. Edward H. Keiser talked informally on 
Some Derivatives of Acetylene, exhibiting speci- 
mens of the new liquid acetylene iodide dis- 
covered by him in January, 1899. He de- 
scribed the methods of making the compound, 
and gave an account of its chief physical and 
chemical properties. The liquid acetylene di- 
iodide solidifies at —21° C. and boils at 185°. 
It has the percentage composition and molecular 
weight represented by the formula C,H,I,, and 
is isomeric with the well known solid acetylene 
diiodide. The speaker announced the discovery 
of a new method of making the liquid acetylene 
diiodide, namely, by heating the solid com- 
pound to 260° in a sealed tube. The solid 
compound is thereby partially converted into 
the liquid compound. Similarly, if the pure 
liquid diiodide is heated to 260° in a sealed 
tube, on cooling down, the liquid will be found 
to have been partially converted into the solid 
compound. All the facts known indicate that 
these two iodides of acetylene are stereo- 
isomers, and that their configuration must be 
represented by the stereometric formulas : 
H 1 Tal I 
NAT, 
I and I 
a acl na Ws 
Since Dr. Keiser has found that the solid acety- 
lene diiodide can be converted into fumaric 
acid, it follows that the first of the two formu- 
las represents the solid acetylene diiodide and 
the second one the liquid diiodide. Further 
experiments upon these compounds are under 
way, and the attempt will be made to convert 
the liquid diiodide into maleic acid. 
Dr. L. Bremer demonstrated some tests for 
glucose by means of anilin dyes, showing that 
nearly all of the ‘alkaline’ anilin dyes, when 
rendered basic by the addition of sodium hy- 
drate, become decolorized, or have their color 
greatly modified, on heating, in case glucose is 
presented. The reactions shown were especi- 
| SCIENCE. 
973 
ally pretty in the case of methylene blue and 
safranine. 
Professor Nipher announced that he had 
nearly completed preparations for the measur- 
ment of wind pressures on the sides of the main 
building of Washington University. The pres- 
sures are to be measured at various points along 
the west end of the building, having a width of 
about 50 feet, and along the north front, which 
is something over 200 feet in length. Simul- 
taneous measurements of wind pressure and 
wind velocity and direction will be made. The 
method used is that tested by him on the trains 
of the Illinois Central Railroad during the 
summer of 1897. The method was described 
in No. 1, Vol. VIII., of the Transaction of the 
Academy of Science of St. Louis. An invita- 
tion was extended to members to visit the Uni- 
versity and inspect the apparatus. 
Professor H. Aug. Hunicke spoke briefly on 
some observations which he had recently made 
on the boiling temperature of hydrocarbons, 
from which it appeared that when T is the 
boiling temperature (absolute scale), ¢ is radius 
of gyration of the molecule, and ¢ is a constant, 
then 72—ac. This holds for the entire series 
of saturated hydrocarbons, including all iso- 
mers. The speaker stated that his observations 
had not yet been extended beyond the series 
indicated. 
ad WILLIAM TRELEASE, 
Recording Secretary. 
DISCUSSION AND CORRESPONDENCE. 
DARK LIGHTNING. 
May I be allowed to make some comment, 
on the interesting article by Professor Wood on 
‘Dark Lightning.’ He is mistaken in suppos- 
ing that my results on the same subject have 
only appeared in a photographic journal. The 
first announcement was a note read before the 
Physical Society of London on June 22, 1889, 
which was published in the Electrician, the 
Philosophical Magazine and the Proceedings of 
the Society. 
Further details were the subject of a paper 
read at the Newcastle meeting of the British 
Association in August of the same year, and an 
abstract of it appears on page 507 of the Annual 
Report. Since then there have been numerous 
