Sheppard, on Colour in Organised Substances. 67 
Soiree, and was very naturally supposed to be a new solution, 
either of iodine, aniline, or some curious chemical compound 
resembling the 4 chameleon mineral.’ But the beautiful 
lambent blue by transmitted light, and the deep carnelian 
red by reflected light, was an effect they were not prepared 
for. When I gave it a name, perhaps for the amusement of 
our lady visitors, who were fascinated with the play of colour, 
a name withal, perhaps, not very far beside the mark, and 
called it 4 polychromatic infusorial water,’ a clue was given to 
its origin, though its nature remained a mystery. You are, 
therefore, earnestly requested to continue your researches till 
you can 4 render a reason.’ I stated that at present you con- 
sider it to be some form of albumen connected with some form 
of life ; and I gave the substance of your story to those who 
had not an opportunity of reading it. 
44 Upon examining the solution with the spectroscope. 
Browning said that it gave the most curious spectrum he 
had ever seen, and Sorby highly values it as being the only blue 
solution in his class C (of which the blood spectrum is the 
type) that gives a dark band in the red rays ; and he wishes 
to have a sample of the confervoid mass for further experi- 
ment. You may therefore be congratulated upon having 
recorded a new fact of special interest to microscopists. In 
addition to your statement I was able to add, from my own 
examination of the solution, that the process of filtering left 
a delicate pink stain upon the paper, without materially 
weakening the colour or colours of the solution ; and on 
evaporating a filtered drop to dryness, and examining it 
under a high power on a dark ground, I was convinced that 
the life you speak of is due to the infinitesimally minute 
monad . This supposition was, curiously enough, confirmed 
yesterday at Browning’s, when we witnessed the voluntary 
motion of these atoms, 4 nature’s invisible police,’ under the 
spectroscope. 
44 But the question was still in every mouth, 4 Whence the 
colour?’ Infusoria, which are themselves coloured, are 
known and described by all observers. Ehrenberg, Carpenter, 
Hogg, &c., describe the red protococcus, or snow plant, the 
Palmella cruenta , 4 of the colour and general appearance of 
coagulated blood,’ the Haematococcus sanguineus , and the 
Astasia hamatodes. The latter, Hogg says, 4 is a kind of 
crimson-coloured animalcule, -g-rs-th of an inchin length, that 
exist in enormous numbers, and give the waters in which 
they live the appearance of their bodies.’ But these do not 
give a permanent stain to the water, nor is there any recorded 
instance of the marvellous variety of colour which your solu- 
