714 
PROCEEDINGS OF THE SOCIETY. 
fitted for use with a Steinlieil lens, and also with a small compound' 
Microscope as might be required. A series of Stenheil lenses was also' 
being made for use with this Microscope, but there was nothing about 
these which particularly called for attention, except that they would be 
inexpensive. 
The President expressed the thanks of the Society to Mr. Beck for 
his exhibit, the form of which was manifestly a very convenient one, al- 
though there might perhaps be, as Mr. Beck had suggested — nothing 
special about it. 
Mr. E, M. Nelson said with regard to the photograph of a coloured 
design, which had been placed on the table, he thought those of a similar 
subject taken by their member, Mr. J. W. Gifford, were better. 
This type of photograph did not have much bearing on photomicro- 
graphy, because it was taken by reflected light, whereas the bulk of 
photomicrographs were taken by transmitted light, and the treatment in 
either case differed somewhat. For instance, it was found that when 
white light fell upon a pigment, such as red, if the reflected ray were 
examined by a spectroscope, all the rays of the visual spectrum would 
be observed ; which shows that in this case of reflected light the photo- 
graphic plate has other raj's than red ones to deal with. With trans- 
mitted light, however, one usually meets with a band of greater or lesser 
breadth where the light has practically been absorbed. A stained sec- 
tion obviously falls under this category. 
The President said the plate which Mr. Nelson had brought was 
certainly a fair effort of photography to give the value of colours, and it 
must be admitted that the isochromatic plates enabled them to go far in 
that direction. At the same time, to get colours shown in black and 
white was never satisfactory ; they were so often of such a nearly equal 
value that it was scarcely possible to express them in that way. The 
difficulty of doing this was also further complicated by the fact that 
there was hardly one eye out of one hundred which could be called pre- 
cisely normal, nearly every one being to some extent colour-blind in 
respect of some of the nicer distinctions between shades of colour, the 
consequence being that to one man these gradations of black and white 
might represent colour, whilst to another they did not. It seemed 
scarcely possible to overcome the difficulty of being able to represent 
not only what photography could do, but also what the eye was capable 
of seeing. The example before them did not enable him personally to 
form a correct idea of the effect of the yellows shown on the coloured 
plate ; the colours themselves might be of equal value, but in any case 
the idiosyncrasy of the individual eye must always affect the result. 
Mr. J. E. Ingpen referred to the colour-sensations produced in the 
reproduction in black and white of objects of varied light-power. In some 
of the fine engravings of Turner’s pictures — such as that of “ The Fighting 
Temeraire,” any one who had seen the picture could mentally reproduce 
the colour-effect when looking at the print. A flesh tint was also some- 
times seen as different from other parts of the subject. Some years ago 
there was a popular process of colouring photographs called “ Crysto- 
leum,” by which good colour effects were sometimes produced, which he 
