146 Cireulation of the Latex, de. [Monts Meopeoncal 
yielded but two which contained anything of interest of a calcareous 
nature. After, then, setting aside the two first sediments, I care- 
fully acted upon what was left with Hydrogen Nitrate (Nitric Acid) 
and procured a small quantity of a sediment, consisting for the 
most part of nothing but the silicious lorica of Diatomaceze. They 
were very few, however; so to procure all the remains of Diato- 
maces and other silicious organisms present in the gathering, I 
took a quantity in the rough state, and, after breaking it down by 
Potassa, acted on it with boilmg Hydrogen Nitrate. ‘Thus I found 
that I had good representatives of all the gathering contained. 
Some specimens, however, are not thoroughly cleaned by boiling, 
even for a considerable length of time in strong Hydrogen Nitrate. 
To such I add either Hydrogen Chloride alone or a few grains of 
finely-pulverized Potassium Di Chromate. In this way, and after 
thoroughly washing with pure water, I have been enabled to obtain 
extremely beautiful specimens of Diatomacez, Radiolaria, and other 
silicious organisms in a good condition for studying them. This I 
am engaged upon at the present time and intend before long to lay 
the results before the Lyceum.—Paper read before the “ Lycewm 
of Natural History,” New York, June 6th. 
V1.— Circulation of the Latex in the Laticiferous Vessels. 
By H. C. Perxins, M.D. 
WirHIn some time I have repeated some experiments (first made 
more than fifteen years since) upon the circulation of the latex in 
the laticiferous vessels of the leaf of Chelidoniwm majus, to which I 
desire to call attention. 
Before detailing these experiments it ought, perhaps, to be 
stated that Amici, Dutrochet, and Mohl deny any visible motion in 
them except such as is the result of injury; while Schleiden says 
“that in the uninjured vessels, the motion of the latex can very 
seldom be successfully shown ;” even in Chelidonium majus it is 
only occasionally possible, and then presents great optical difficulties. 
Now, I find, by potting a young plant of this kind, and placing 
any young leaf between two strips of glass (upon which a drop of 
glycerine has been put) in such a manner as to bring the under side 
of the leaf uppermost on the stage of the microscope, so as to throw 
the strong reflected sunlight upon it from the mirror below, that— 
First, there is occasionally either a nearly total want of motion 
or only a very slow one of the coloured granules, or at times a very 
rapid motion of the particles to be seen, running from right to left, if 
the vessel happens to run horizontally on the stage, or toward me if 
the vessel runs from the outer to the inner border of the stage, and 
