Connell Apparatus manufactured and serviced the anesthesia machines used at Presbyterian Hospital. During Apgar's first
years as director of the Anesthesia Division, the hospital grappled with the problem of explosions resulting from accidental
ignition of anesthesia gases in the operating room. It was not always clear where the sparks originated in these accidents,
and Connell worked with the hospital staff to discover which equipment and materials were causing them. In this letter, Connell
described a modification to the equipment and other methods to reduce the risk of sparking from static electricity.
Item is handwritten.
Number of Image Pages:
2 (1,727,659 Bytes)
1939-03-09 (March 9, 1939)
Connell, Karl A.
Original Repository: Mount Holyoke College. Archives and Special Collections. Virginia Apgar Papers [MS 0504]
Reproduced with permission of Karl Connell.
Medical Subject Headings (MeSH):
Establishing a New Specialty, 1938-1949
Letter from Virginia Apgar to Karl A. Connell (March 21, 1939)
Letter from Allen O. Whipple to Virginia Apgar (April 5, 1939)
Letter from Karl A. Connell to Virginia Apgar [ca. 9 April 1939]
We evidently have been grinding in the shunt valves too tight and without the right lubricant. The lubricant we have now found,
a boiling water proof, sodalime proof lubricant used in hooking marine propellers and water pumps. We will send you a box
and fix your "static" for good and all. The new piston installed by Puritan may leak, for each must be re fitted (only
not so tight).
The status of intercoupling is to make a staticless high resistance cuff by a couple of winds of [ . . . ] 2 gauge on patients
arm and anesthetist wrists and onto the knots of these clip a bull dog slit, connect to insulating wire that originates from
the machine. This is OR at 15 percent of norm humidity. Your long born days is OR at 30 percent norm humidity. I have done
a great deal of work in starting "explosions," i.e. igniting Oxg acetylene. Never has the gauge given an igniting
spark. The self generated static walks thru the metallicized
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high resistors of Prof Hoilon of the M.I.T. as tho nobody was home and ignite gas every time.
Another unique finding is that with a high charge of static on myself, I can polarize a small metal body insulated from myself
or can polarize the wet surface of rubber and get a spark to the "machine" and cause ignition. This then was the source
of your spark, for disagreeing with Dr Williams, I do not think that dry rubber surface unless laboratory dried has the generating
capacity to make and hold an igniting spark. Whereas a damp bag interior can be polarized and spark O.R. just like a leyden
What I want especially from you.
(x) 1st was there a metal neck on the Heidbrinks bag which blew. If so the spark is easy to explain [ . . . ] charged from
the anesthetist. Or if there was rubber to metal, and the (y) anesthetist hand was distant from the apparatus and well insulated
by the bag, then we can best assume a polarization of wet bag interior to build the fairly substantial spark necessary to
ignite I have not been able to ignite with mere gloves, or SLEP fire, or phosphorescent (in the dark) charges.