824 



SCIENCE. 



[N. S. Vol. III. No. 74. 



The method employed is that of the centri- 

 fuge, an apparatus which consists of a series of 

 geared wheels driven by hand or belt, and so 

 arranged as to cause an upright shaft to revolve 

 up to a speed of 8,000 revolutions per minute, 

 corresponding to 50 revolutions per minute of 

 the crank or pulley wheel. To this upright 

 shaft is fastened an attachment by means of 

 which two funnel-shaped receptacles of one 

 litre capacity each may be secured and made to 

 revolve with the shaft. The main portion of 

 each of these receptacles is constructed of spun 

 copper, tinned. When caused to revolve for 

 one or two minutes the entire content of sus- 

 pended matter in the contained water is thrown 

 to the bottom of tubes properly placed, from 

 which the amount may be read off by means of 

 a graduated scale. Ed"w. J. Nolan, 



Recording Secretary. 



NOETHWESTEEN UNIVERSITY SCIENCE CLUB, 

 MAY 1. 



Prof. Hough in the chair and thirty-eight 

 persons present. Prof. Crew and Mr. Basquin 

 presented the topic, ' The Identity of Light and 

 Electricity.' "Kelvin's prediction that the 

 discharge of the Leyden jar was (under certain 

 conditions) oscillatory and Maxwell's eqiiations 

 for the propagation of electro-magnetic disturb- 

 ances were derived and explained. The sub- 

 ject was illustrated by Faraday's experiment 

 shoAving rotation of plan of polarization in a 

 magnetic iield. The nature of wave motion 

 was shown by the Melde experiment, Kundt's 

 tube and Weber's wave trough. The equiva- 

 lence of capacity and self induction was illus- 

 trated by Lodge's experiment showing reso- 

 nance between ten Leyden jars. The Lecher 

 modification of the Hertz experiment was shown 

 in various forms, the nodes of the electric waves 

 being detected by vacuum tubes and bridges. " 

 A. R. Crook, 



Secretary. 



EvANSTON, III. 



THE ACADEMY OF SCIENCE OF ST. LOUIS. 



At the meeting of the Academy of Science of 

 St. Louis of May 18, 1896, Professor C. M. Wood- 

 ward presented a critical examination of some 

 of the mathematical formulte employed by Her- 



bart to represent mental phenomena, in which 

 these formula were criticised as inadequate. 

 Though not considering any formulte likely to 

 be adequate, from the nature of the case, the 

 speaker offered a substitute for the Herbart 

 formulae pertaining to the bringing into con- 

 sciousness of a sublatent concept through the 

 suggestion afforded by another concept similar 

 in some respects while differing in others. 



Dr. A. N. Ravold made a report on the 

 use in St. Louis of diphtheria anti-toxine, pre- 

 pared by the health department of the city. 

 During the past winter 342 cases of diphtheria 

 had been treated with this serum by 93 physi- 

 cians. Doses of from 2.5 to 100 cc. had been 

 administered. As a rule, the recovery was far 

 slower when the quantity used was small than 

 when a larger quantity was employed. Usually 

 the serum was administered only once. In 

 about half the cases a decided change for the 

 better was noticeable within 24 hours, and 

 these cases were practically cured within 48 

 hours, although attention was called to the fact 

 that for some weeks the throat of a convales- 

 cent is a breeding place for the diphtheritic 

 bacilli, the virulence of which did not seem to 

 be diminished by the serum treatment. Of the 

 cases reported on, 9.06 percent, only died, and 

 as a considerable number of cases were hope- 

 less when treatment was administered, the 

 patients dying within 24 hours thereafter, it 

 was considered fair to deduct these deaths from 

 the total, which reduced the mortality to 4.6 

 per cent, when the serum was administered in 

 the earlier stages of the disease. The injurious 

 consequences of administering the serum were 

 fully considered, but held to be practically in- 

 significant. It was also stated that when used 

 on persons who had been exposed to, but had 

 not manifested the disease, the serum proved 

 an unfailing means of conferring immunity for 

 a certain period of time. Among the advan- 

 tages in the use of this serum was mentioned 

 that of lessening the chances of secondary in- 

 fection, so frequent after an attack of diphtheria. 



A committee presented resolutions on the 

 death of Dr. Charles O. Curtman, for many 

 years a member of the Academy. 



Wm. Trelease, 



Eecording Secretary. 



