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24 March 23rd 1843

Made an experiment today on the "pasivity" of 
iron. A piece of iron wire was heated, and 
then suffered to cool. On plunging this into strong 
nitric acid, no action was perceptible, and
this state is called pasivity. The idea had
occurred to me that perhaps if the wire 
were magnetized and demagnetized while 
in the acid, the natural state would return. 
On making the experiment however, the effect
was not produced. The iron remained in 
the acid unaffected. The experiment consisted
in surrounding the glass tube containing the acid,
and into which the wire was dipped with a 
coil. 

When the passive wire was made, the
negative element of a galvanic [[encircled]]couplet [[encircled]], the
passive state was destroyed, and action 
produced. 

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April 24th 1843      25

Being in Phild, I was requested, or I should say invited,
 to call and see a new microscope, lately imported by
Dr. Beck(son of P. Beck Esq.) from England, this is the most perfect instrument of the kind which has yet reached this country. It is furnished with all the arrangements 
for ease of use as well as for exhibiting everything at present known, in reference to the microscope.
  With this instrument, I made two original observations,
 or at least two which I do not know to have been
 previously made. The first was in reference to 
starch. This substance is contained in minute [[membraneacious?]] bags which, when wet, swell and burst; the starch has therefore been considered a kind of organic substance. Each particle under the microscope presented 
an appearance similar to the nodules of indurated
 clay found about Albany [[image-drawing]] of the appearance of the figure. The idea occurred to me to view this by means of polarized light, the effect was beautiful, each particle of starch showed the action called depolarization of light and exhibited the black cross similar to that shown by a crystal of carbonate of lime when viewed parallel to the optical axis.
This fact proves that the starch  within the bags is in a state of segregation approximating crystalization. The black cross was not perfect, but the arms were curved somewhat irregularly the centre of the cross in each case was the same as that of the concentric circles which were observed on the surface of the particle without the aid of polarized light.
[See the figure]

The other observation with this microscope was in reference to capillarity. According to the theory of Poisson, the fluid which comes in contact with the plate of glass suffers a change of density. The idea occurred to me sometime ago, that if this were true to any appreciable degree, it might be rendered evident by means of the transmission of polarized light. The effect was as I anticipated. When a small quantity of water was placed between two glass plates, separated by a frame of thin writing paper, and this submitted to the action of polarized light

Transcription Notes:
09-28-14-BW "membraneacious" = misspelling of "membranaceus" http://en.wiktionary.org/wiki/membranaceus