Physics and Chemistry. 417 
I subjoin a list of the contributions to Acoustics by Dr. Sondhauss. 
They have been mostly pee as s Programmes, and are therefore not 
generally accessible in this country,* 
= Color of Blood Globules.—Editorial Note to Dr. Reuben’s paper, Pp. 
—With regard to the color of single blood globules, it must be ad- 
iia that when wenn blood globules are viewed under a magnify- 
ing power of from 600 to 800 diam., they certainly appear colored dis- 
tinctly yellow, and not ia If now one or two plates of cobalt glass be 
placed under the stage, or over the eye-piece, the blood globules by virtue 
of a yellow = actually do cut off much of this blue light, thacy 2 
t less than 50 or 60 cent. They then — much darker than 
the general field: their cnt at first sight seems simply dark grey, atten- 
tive examination shows it dark bluish-gr 
Compare also Heteohl ak on ~_ change of aa by an increase of thick- 
ness. Herschel on Light, Sect. 4 
In the 8th No. of the Aligeméine Encyklopedie der Physik, (Dec. 
1860), Hetmuontz details some observations of Purkinje on this subject, 
which agree with those of Prof. Wm. B. Rogers already published in this 
Journal. Helmh holtz seems in doubt whether to attribute this —— 
shutter of a dark ea re appeared then colored; reckoning 
rom the centre, white or bluish, darker blue, white, dark ring, white, 
greenish yellow, reddish. It is unfortunate that her he nor other 
observers have detailed the rates of motion they communicated to the 
slits, so as to re comparison of observations possible. I infer from 
a slight repetition of these experiments that the rates were much lower 
than those empl me. See ) of this Journal, 
ing par 
and oe: been ascribed by Vierondt, to the blood circulation in the retina, 
g momentarily visible.+ I have often caught distinct Laem 
of this, spiksianck 
* (I.) Ueber die Schalischwingungen der Luft in erhitzten G Glaserchern, 
Ricerten Pfeifen von ungleicher Weite—Ann. ch. u. Ph. Ixxix, pp. 1-84. 
ikreisel und der trobischen Pfeifen, 
(LIL) Ueber die beim Austrémen der den .— Programme der 
Realschule zu vo Helene, 1853, Pp. 13h fe sigs in Ann. hag u. Ph. xci, p. 129, et infra. 
(IV.) Ueber die Chemische iF Baafachale zu Neisse, 
_ 1859, pp. 1-43. _ (A very learned and’ hs resume, caesar Wik valuable contribu- 
tions to the subject). 
+t Pi —— Optik, by H. Helmholtz, 1860, page 381. 
