
          I have been constructing a car. acid apparatus,
which I have tested thoughly several times, and 
it stands it - (stop-cocks and all) perfectly; and
once I obtained a little of the solid. Just as 
I was ready however to operate with it, every
[?-cell] as in this plan failed , and I can not 
[waiting?] for a new crop, of which we begin to 
have some indications! It is destitute of [?],
and no regard has been paid to the appearance
of the thing; but I think I shall astonish
the N. York manufacturer, with regard to
the cost! And a little caution perhaps
[added: should] be observed in this respect, till I have proved
it further! How large should this tube be which connects
the generator and receiver as well as the 
apparatus of this stop-cocks? I have thought I may
ave made them too small.

What are the peculiarities of the [F.-V.] Raspail microscope
of [added: which] of Prof. Baily speaks in his article on [?]
infusoria, and where can it be obtained? How do
you use the glass globules you prepare for lenses? In 
the common comp. microscope! I have some specimens
of infusorias, as I suppose, from the state of Maine and
other places, but have not the means of determining them.
Have you any specimens to spare?
Accept [?] of my sincere regards
Respectfully yours etc. John Johnston
        