If you are near a reasonable sized University, then contack them for access
to liquid nitrogen. It costs $0.19 per liter as opposed to $0.10 per liter
10-20 years ago. That's a lot cheaper than milk!
If you are in a rural area, contact your county agricultural agent.
Artificial insemination of cattle requires the storate of the semen in LN2,
so most of the agents have both a dewer and the LN2 which they CAN lend if
you, if they are in the right mood.
Otherwise, look in the yellow pages for an oxygen supply for medical
purposes. The hospitals have to get oxygen, and LN2 is a byproduct of that
production. As mentioned, welding suppliers often have LN2 for the same
reason. Airco, Big Three Welding, are a couple of firms.
Good luck, Karl
____________________________________________________________________________
Dr. Karl I. Trappe Desk:(512)471-4152
Physics Dept-Mail Stop C1600 Office: (512) 471-5411
The University of Texas at Austin FAX: (512) 471-9637 (other building)
Austin, Texas 78712-1081 E-Mail:trappe@physics.utexas.edu
____________________________________________________________________________