154 DR. KEBER, ON THE POROSITY OF BODIES. 



reddish or greenish tinge. Upon long examination he also 

 noticed that the borders of the dust-particles, as well as their 

 finer indentations and inlets, frequently presented exactly the 

 same reddish and greenish edges. This accordance in the 

 colouring of the borders, with that of the apparent spaces in 

 the substance of the dust-particles, could not, in the Author's 

 opinion, do otherwise than serve as a confirmation of his belief 

 that he had before him real spaces and minute orifices. More- 

 over, with the alternate elevation and lowering of the object, 

 and with alternately increased and diminished illumination, he 

 distinctly saw the light flash through them. To the above, which 

 really includes the whole of Dr. Keber's discoveries, we would 

 merely add that his observations were usually made with a 

 magnifying power of 200 diameters and with an aplanatic 

 eyepiece, and with full transmitted light. With this power he 

 was able to perceive in all bodies whatsoever examined by 

 hiin — including metals, minerals, «Scc. — the following parti- 

 culars : 1. As it would seem, that they are composed of 

 scales, all of which are constituted of a delicate net-and- 

 lattice-work of variously interlaced fibres, with lamellfe more 

 or less covering one another, which however, partly between 

 them, partly in their substance itself, present a multitude of 

 minute, irregularly-shaped roundish, elongated, indented and 

 angular orifices, spaces or rifts which are sometimes dendriti- 

 cally branched, and form a system of communicating hollow 

 interstices or passages. All to be seen and measured with a 

 linear magnifying power of 200 diameters, and with an object- 

 glass, by Dr. Keber's confession, very far from corrected for 

 chromatic aberration ; as we have reason to believe is the case 

 with many object-glasses used by German observers ! 



The absurdity of these assertions, and of the pretended 

 discoveries of Dr. Keber, will be so glaringly manifest to any 

 one who has had the slightest experience with the microscope, 

 that we should not have occupied a page of the Journal with 

 them had it not been for their appearance in a periodical of 

 such high scientific repute as the ' Philosophical Magazine,' 

 and under the auspices of one who, with all his obstinacy in 

 the retention of exploded views, deserves the greatest respect 

 from every physiologist and microscopical observer. We are 

 sorry to say, however, that Dr. Barry's reputation as an 

 observer will not be enhanced by his fostering of Dr. Keber's 

 extravagant notions ; nor do we perceive either that that 

 imaginative microscopist has much to thank Dr. Barry for, 

 in what the latter terms his ' Confirmations' of the dis- 

 coveries. For, according to the ' Confirmations,' the German 

 observer's pores are not pores at all, but the nucleoli of a flat 



