IS76.J 
535 
Notices of Nooks. 
Patents to investigate the reality of the alleged results. After a 
minute inspection he is reported to have declared that all General 
Pleasanton’s statements concerning the action of blue light were 
confirmed. 
But if General Pleasanton is in the right, the wonderful and 
salutary effects of blue light upon organic life is by no means 
the most extraordinary of its properties. Heat is also, in some 
unaccountable way, developed in the passage of sunlight through 
blue glass. We read — “ During the winter of 1871-72, which 
in this city was a very cold and rigorous one, two ladies of my 
family, residing on the northern side of Spruce Street, east of 
Broad Street, in this city, — who, at my suggestion, had caused 
blue glass to be placed in one of the windows of their dwelling, 
associated with plain glass, — informed me that they had observed 
that when the sun shone through these associated glasses in 
their window, the temperature of the room, though in mid- 
winter, was so much increased that on many occasions they had 
been obliged during sunlight to dispense entirely with the fire 
which ordinarily they kept in their room, or, if the fire was 
suffered to remain, they found it necessary to lower the upper 
sashes of their windows, which were without the blue glass, in 
order to moderate the oppressive heat.” Further, a “ distin- 
guished German scientist,” not named, is quoted as declaring 
that “ one-half of the fuel heretofore required can be saved by 
thus utilising sunlight.” Yet in an earlier portion of the work 
we find the author expressing the opinion that a vinery roofed 
with blue glass would be cooler than one constructed of un- 
coloured glass. “ Should too much (blue glass) be used it would 
reduce the temperature too much.” It need scarcely be said 
that experimentalists have not found the blue and violet rays of 
the spedtrum to be the hottest portions. 
We should feel much greater confidence in General Plea- 
santon’s observations if he had been content to place them simply 
before the world as novel and — if verified — important faCts ; but 
he goes much farther, and deduces from them an entire new 
philosophy. Into these his doCtrines it will be early enough to 
examine when the aCtion of blue light shall have been satisfac- 
torily ascertained. 
Hydraulic Experiments at Roorkee , 1874-5. By Capt. Allan 
Cunningham, R.E. Roorkee : Thomason College Press. 
An experimental examination of surface and sub-surface veloci- 
ties in rivers, flowing canals, &c. 
