The formula of Conen, as well as Rosa’s method give too small 
values for the self-inductaace. 
An example of the extreme accuracy, obtained with the very 
simple formula (16) in computing the self-inductance of a cylindrical 
current sheet, as compared with the value calculated by the exact 
formula of Lorenz!) with elliptic integrals, may be given here: 
Example 2. 
[= 30 Cm. de o Cli. (sh), 
calculated : 
by formula (16) LL, = 4.540489 millihenry. 
,, Lorenz’s formula L; = 4.540486 4 
Physiology. — “On the permeability of red bloodcorpuseles in 
physiological conditions, more especially to Alkali and Larth- 
alkalimetals’. By Prof. H. J. Hamsereer and Dr. F. Busanovic. 
Mr. G. Gryxs has published a short article in this paper’), in 
which on the ground of some calculations he thinks it desirable to 
object to some of the conclusions we drew from our experiments 
on the subject mentioned above. (Proceedings of June 25th, 1910). 
We feel convinced that his remarks would not have been published, 
if he had waited for our more explicit communications on this sub- 
ject, in the “Archives Internationales de Physiologie”. As appears 
from a note on the first page of our paper we had promised these, 
and they indeed appeared shortly after *). 
In this treatise a detailed account is given of the experimental 
method and moreover by way of example a lengthy report is added 
in an appendix, containing full particulars of one of the series of 
experiments. In these proceedings it is hardly possible to enter into 
details, especially when, as in this case, extensive investigations are 
concerned. A detailed description is better in its place in a physio- 
logical periodical. 
This remark might suffice, but it is perhaps of some use that 
those who cannot immediately consult the ‘Archives Internationales” 
are made acquainted with the mistake of Dr. Gryns. 
1) Bull. of the Bur. of St. V, 41. 
2) These Proceedings of October 29, 1910. 
3) La perméabilité physiologique des globules rouges, spécialement vis-a-vis des 
cations. Archives Internationales de Physiologie. Vol. X. p. Ll. Appeared September 
24th 1910. 
