This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
Certain nerve-phenomena, whether direct or indirect, are determined by manganese salts. Toxic doses cause death with convulsions, and 1/2 to 1 gramme injected into the veins of rabbits or dogs produces cramp and death from heart-palsy, or else faintness and weakness and slower death with fatty degeneration (Laschkewitz). The pupils are dilated, the temperature unaffected. Rabuteau injected a little more than 1 gramme into a vein of the hind leg of a bitch, and at first there were no symptoms, but on the following day tetanic convulsions set in, with trismus and opisthotonos, and death followed shortly afterward: the white substance of the spinal cord was shrunken, the gray matter congested.