( 706 ) 
Physiology. — “The Camera silenta l ) of the Physiological Labo- 
' ratory at Utrecht ”. By Prof. H. Zwaardkmakek. 
(Communicated in the meeting of February 26, 1910.) 
The extension of the means of communication calls forth nearly 
everywhere to a higher or lower degree the disadvantages connected 
with the continual presence of noise. Therefore we want in many 
instances apartments free from sound, and that at first in those cases 
in which the continuous existence of disturbing sounds forms an 
insuperable impediment. Such cases present themselves: 
a. in acoustic experiments when the observations have to take 
place in the proximity of the minimum perceptibile; 
b. in public consulting rooms for diseases in the ear where through 
the coming and going of patients the required silence never reigns, 
and more frequent visits render every minute investigation well nigh 
impossible, consequently cause also uncertainty of diagnosis, of advice 
and of decision in case of examination ; 
c. in modernly built hospitals, which with their smooth walls, naked 
floors, construction of stone and iron, etc. show a kind of strong reson¬ 
ance, and which, through their many technical ‘institutions’ can never 
be quiet; the consequence is the impraciicableness of a really efficient 
percussive and auscultatory examination 
Since 1904 a camera silenta (2.28 X 2.28 X 2.20 M.) has been 
nsed for the purpose mentioned under a in the Physiological Labo¬ 
ratory at Utrecht") and also since that time my advice has repeatedly 
been asked in the building of new laboratories, polyclinics and 
hospitals in this country and elsewhere. In connection with this I 
venture here to pronounce the conviction that an apartment free from 
»und intended for one of the three above mentioned purposes, 
' h ' 6 40 3at ‘5 V " ree condi ‘ions in order to preclude disappoint¬ 
ment. These conditions are: f 
jmner surface of the apartment has to be covered with 
iC ^ “ 3 katpuent from Laevius used by “loca", 
°; “ s shortness, preferable to saentiosns. 
-) Ned. Tijdschr. v. Geneesk. 1905, Part I 
Bd. 54, p. 247. ’ 
p. 571. Zeitschr. f. 
