Twenty-one grams was the answer given by the English scientist Duncan MacDougall in a scientific study he published in 1907. The 19th century was filled with classic Gothic novels, including Frankenstein, the Picture of Dorian Gray and Jane Eyre just to name a few. So, like many people of his era, MacDougall was fascinated by death and what happens after it. He surmised that if we have a soul then it ought to have a weight, thus the weight of the diseased must decrease when the consciousness has left the body. To prove the theory, MacDougall set out to find people near the point of death – and additionally, people that were incapable of moving so that the beam of the scales could be kept balanced. He favoured Tuberculosis patients – the progression of Tuberculosis was quite predictable, and with the aid of X-Ray, they were able to estimate the time when the patient was approaching the end of their time. MacDougall found his victims in the Dr Cullis institution where over two thousand patients were taken up and treated with the method of “Faith cure”. Suggested by the name, comfort was more readily offered than scientific treatment; nevertheless, Dr Cullis recognised that the potential proof of human soul could have a spiritual importance.
There were a total of six dying volunteers, and they were transferred to a cot suspended from Fairbank scales, which have an uncertainty of a tenth of an ounce. MacDougall and other physicians would observe the change of weight at the exact time of death. When the first man was transferred onto the cot, he continued to breathe for a further three hours and forty minutes, until suddenly, coincidentally with death, the beam moved back three quarters of an ounce (roughly twenty-one grams) without rebound. Another five patients would be observed by MacDougall – patients two and three dropped half an ounce, patient four was discounted due to scale failure, patient five dropped 3/8 of an ounce and patient six died before he was transferred to the cot, so a set of four results were obtained. MacDougall failed to observe any change in weight in dying dogs, as he expected because he believed that animals don’t have a soul.
Unsurprisingly, his research has received plenty of criticism, and the difference in results between humans and dogs was explained by August Clarke – the cooling effect of breathing no longer takes place when the body dies, so there would be a burst of sweat which would evaporate, explaining the difference of twenty-one grams as dogs don’t have sweat glands. Additionally, the poor sample size of six volunteers (of which only four provided actual data), would have been identified by any A-level Biology student when they practise their evaluation questions. Six people is far from representing the whole human population. As modern medicine progressed, the point at which death occur can also be debated; there are two categories of legal death: cardiopulmonary death, which is the irreversible cessation of heartbeat, and brain death (self-explanatory).
Sadly, the experiment was far from what he claimed to be “rounded by every precaution to obtain accuracy”, but the creative idea of weighing souls is still very much welcomed by me (apart from the part where he used drugs to poison fifteen dogs, to end on a real high).
