Dr. Duncan MacDougall decided he wanted to find out whether the soul was material or inmaterial he wanted to weigh it so he took six patients who were dying off tuberculosis and put them on special weighing bed and weigh them for the last three hours of their lives as they were dying what he noticed was as they expired each one lost weight on average about 21 grams that's the weight of 2 american silver dollars and he concluded therefore the weights of human soul was 21 grams what he then did was to do the same experiment with dogs and he took a whole lot of dogs and when they died he weighed them what he found was unlike the humans the dogs didn't lose weight so he concluded while human has a soul dogs don't 