1901] MICROSCOPICAL JOURNAL. 177 
but of different construction. This camera is fitted with 
a pair of “goggles” and a velvet bag for the head. An 
instantaneous shutter, made of thin sheet aluminium,lies 
almost in the plane of the sensitive plate and bears white, 
discs upon which the focussing is done,and the image is 
watched until the time for exposure.—Sc2. Gossip. 
MICROSCOPICAL MANIPULATION. 
BLEACHING BonzE.—Place articles ina glass vessel with 
oil of turpentine, expose to sun for three or four days, a 
little longer in the shade. Turpentine acts as oxidizing 
agent, forms acid liquor, which sinks to bottom of ves- 
sel, and strongly attacks bones if allowed to touchit. To 
prevent this they should rest upon strips of zinc, so as to 
be a fraction of an inch above bottom of vessel. It also 
applies to ivory and woods of various kinds. Prepare so- 
lution of fresh chloride lime 1, water 4. Put bones in this 
and allow to remain for a few days. Then take out, 
wash,and dryin open air. Place in mixture of unslaked 
lime, bran and water, boil untilfree from fatty substances, 
and are white. Pour oi] of turpentine overthem in tin box, 
which éan be hermetically closed, let remain for ten hours, 
remove, and boil for three hours in soft-soap water. Skim 
off impurities, cool hot water with cold, dry bones on pine 
boards in open air, protected from the sun.—Hng. Mech. 
CoLoRING MATTER OF ALGH.—R. Kolkwitz (Chem.Cen- 
tralblatt), says the color of the cyanophycewg, which are 
so abundant in the effluent of sugar works, and are met 
with both in fresh and salt water, is due to the presence 
in the plants of a fine indigo-blue water-soluble coloring 
matter, phykocyanin, as wellas chlorophyll. It may be 
obtained in a crystalline state by treatment with ammo- 
nium sulphate, in the same manner as albuminoids may 
be precipitated. It is improbable that this body exercises 
any toxic effect upon fish; the harm caused to them he 
