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A square metal instrument with a silver handle built into the case on top. On the front left of the instrument, there is a dial marked “Intensity” which ranges from 0-100. Below this is the manufacturer’s label and a Power switch with a small light. On the front right, there is an analog timer with a glass front which goes from 0-60 seconds in 5 second increments. This has a red button at the bottom. At the bottom front, there are a red and black knob marked “Current Monitor”. To the right of these are white, black and red knobs labelled “GND”, “Out 1”, and “Out 2”, respectively. the latter two are written on tape over the knobs. There is a cord that attaches to the back and two black dials labelled “fuse”.

Accession Number: 2011.psy.30

Alternative Name:

Primary Materials: Metal, Plastic


U of T Label on top:” Department of Psychology Research Equipment No. 2042 GS 78.”

There is a warning label on the top “The purpose of this LM-3 is to create lesions by destruction of living cells. Grass Instrument Company assumes no responsibility whatsoever for any injuries to the operator of this equipment or to any animal or human subject as a result of its use or abuse. We advise that its operation be restricted to qualified personnel. Grass Instrument Co., Quincy, Ma, USA.”
In addition, there is a label on the top marked “McDonald.”

Dimensions (cm): Height = 15, Width = 15, Length = 21


Destruction of living tissue for experimental purposes.

Condition: Excellent. Minor scratches and dirt.

Associated Instruments:


Grass Instrument Co., Quincy, Mass, U.S.A.

Date of Manufacture:


Dept. of Psychology, University of Toronto

Additional Information and References:

Historical Notes:

The company was founded in 1935 by Albert Grass, who developed the first commercially successful EEG.
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