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From the Stacks 

November 24, 2009

On “Origin” and “Evidence”

Being a librarian, I tend to think of my work life as a series of questions and answers. Answering questions is essentially what I do for a living, and answers are the product of a hard day’s work.

I was quite happy to pick up Evidence of Evolution, a new book with text by Mary Ellen Hannibal and photographs by Susan Middleton, and see that it begins with questions.

Quoth Mary Ellen: “Why do butterfly wings have so many different patterns, and if a snake is a reptile and an eel a fish, why do they look so similar? A hundred and fifty years ago, Charles Darwin addressed these questions with the publication of his seminal work, On the Origin of Species. In it, Darwin posited the theory of evolution based on natural selection as the answer.”

150 years ago today – November 24, 1859 – Charles Darwin’s On the Origin of Species by Means of Natural Selection was published. Evolution was not a new idea, but the concept of descent with modification, the idea that change is powered by modifications in gene frequency over time, driven by a process dubbed “natural selection” captured the scientific imagination. All the copies of Origin (only about 1,250 were printed in the first run) sold out on the first day.

It is a fitting time to celebrate the publication of Darwin’s great work alongside the release of Evidence of Evolution. This new book features spectacular photographs of specimens from the Academy’s research collections, accompanied by text that illuminates how scientists see and use these specimens as, well, evidence for evolution.

It is the sign of an important question that we’re still contributing to the answer 150 years later.

Evidence of Evolution, photography by Susan Middleton and text by Mary Ellen Hannibal is available for purchase from the Academy’s Scientific Publications.

Since a copy of a first edition of Origin just sold for $172,000 US at auction, picking up a copy of Evidence of Evolution is a more affordable way to commemorate this momentous day.

Keep asking questions!

Filed under: Photography,Research — Librarian @ 12:55 pm

November 3, 2009

Nitrate negatives

A significant aspect of scientific expeditions is visually documenting

a location, people, or specimens. Here in the archive, it is our job

to preserve these images. While these days most scientists and

photographers are using digital cameras, which present their own

preservation issues, our earlier manuscript collections contain

physical photographs and film negatives. There are three types of film

base: cellulose nitrate, cellulose acetate, and polyester. Both

nitrate and acetate can break down over time and the fumes they

release can harm the collections around them. In fact, nitrate film,

first manufactured by Eastman Kodak in 1889 and continued to be made until

the early 1950s, is highly flammable. Nitrate film can be difficult to identify from

other film bases unless it is seriously deteriorated or clearly marked. The North East

Document Conservation Center has a wonderful preservation leaflet

about how to identify nitrate film and how to test if your film is


We didnt need to test this negative because it is marked Eastman - Nitrate - Kodak on the left edge.

We didn't need to test this negative because it is marked "Eastman - Nitrate - Kodak" on the left edge.

So, what can we do to capture the images on nitrate negatives and

still protect our other materials from fumes and possible fire? We are

in the process of a nitrate separation, digitization, and storage

project. As we find nitrate negatives, we digitize them by making a

high resolution Tiff image. This is our archival master image. The

negative is then placed in a paper enclosure and labeled in pencil. A

large group of negatives is put in an archival box, heat sealed in a

Marvelseal wrapper (to prevent moisture from getting in) and then

placed in a ziptop plastic bag. The bag is placed in our flammable material

storage freezer and kept at -20 degrees centigrade. This helps preserve

the image on the negative and protects our other collections from fumes

that nitrate generates as it degrades. So far, there are approximately

6,000 frozen negatives in our freezer and we have another 800

negatives to add to the freezer as part of our most recent project.

The images below are nitrate negatives that have been digitized in the

last year.

Election of Pope Benedict, 1914.

Gustav Eisen negative labeled "Election of Pope Benedict XIV 1914". Thanks to a comment from J.S. Oishi we know that election was actually of Pope Benedict XV.

Ynes Mexia negative of "Lake Mirror. Dawn." Yosemite National Park, 1921.

Danielle Castronovo – Archives and Digital Collections Librarian

Filed under: Archives,Photography — Archives & Special Collections @ 3:17 pm

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