Ricin

Ricin is a toxic lectin found in the seeds of the castor oil plant.

Characters poisoned with ricin

 * Lois Hargreaves - The House of Lurking Death
 * Miss Logan - The House of Lurking Death (self inflicted, non fatal)
 * Esther Quant - The House of Lurking Death
 * Dennis Radclyffe - The House of Lurking Death