Alexis Soyer's famine soup

I was looking through Jane Grigson's book English Food, and caught a reference to Victorian celebrity chef (and inventor of the kitchen timer) Alexis Soyer:

The French chef of the Reform Club, the great Alexis Soyer, caused a sensation by nobly going over to Ireland in the potato famine to save Irish souls with his soup (like most benevolent soups of the time, it was not very nutritious).

Obviously, Jane Grigson is not to be argued with over statements like that any more than Elizabeth David is. I was curious about just how not-very-nutritious it was, though, so I went looking for the recipe.
( recipes and comparisons )