Electrostatic force microscope for probing surface charges in aqueous solutions.

A scanning force microscope was converted to an electrostatic force microscope by charging the usually neutral cantilever with phospholipids. The electrostatic force microscope was used to study surface electrostatic charges of samples in aqueous solutions. Lysozymes, DEAE-Sephadex beads, 3-propyltriethoxysilane-treated glass and mica were imaged in water or phosphate buffer with electrostatic force microscopy. The adhesion force measured when a charged probe and oppositely charged specimen interacted was up to 500 times greater than when a bare probe was used. This dramatic increase in measured adhesion force can be attributed to the energy required to break the salt bridges formed between the charged probe and the specimen. The use of phospholipids to functionalize the cantilever tip allows the incorporation of other biomolecules and ligands that can be used as biologically specific tips (e.g., receptors, drugs) for the study of intermolecular interactions.

An account of my quarter bills, charges &c from July 11th 1743 to July 13th 1748 at Harvard College

Handwritten account book kept while Storer was a student at Harvard College. The well-organized volume is arranged by expense type and then date and was updated periodically, usually quarterly. The information offers a glimpse at the expenses of a Harvard student and provides information about the larger community that supported student life. The precise entries indicate the lifelong habits of Storer as a careful and methodical financial manager that would prove so valuable when he served as Harvard's treasurer more than thirty years later. Storer documents accounts with the steward, butler, sweeper, glazier, barber, and lists these individuals by name. The volume also includes notes on expenses for boarding, transportation, wood, and pocket expenses. While most entries do not list specific purchases, Storer provides details on the cost of a Harvard Commencement in 1747 (including the cost of a diploma, money to the President, hiring a house, a boat, a woman, and "2 Negroes"), and a specific accounting of the different food purchased for the event; Storer also lists expenses for an 1748 "supper for the graduates."

Minutes explaining difference between first act. rendered Judge and charges to that date entered on Estate Book, 1820 February

Two pages with calculations and notes relating to the differences between the Estate Book and the account rendered by the Judge of Probate.