Polite Dissent

Young Mary Thayer needs a blood transfusion or she will die. Unfortunately, she has a rare blood type and there are no donors. Luckily, the Spirit discovers that he has the needed blood type (”Type A-1”) and rushes to the hospital to save her.

What exactly is type A-1 blood?

When we describe a person’s basic blood type, we list two factors: the ABO and the Rhesus. The ABO factor is fairly self-explanatory — this is what determines whether a person is blood type A, B, AB, or O. The ABO blood types were discovered in 1901. The Rhesus factor, usually shortened to “Rh-factor”, describes a person’s blood type as being either negative or positive. By putting the ABO and Rh systems together you get the eight basic blood types: A+, A-, B+, B-, AB+, AB-, O+, and O-. There are other minor factors as well, such as Kell and Duffy, but these only become important in rare circumstances such as transplants.

You’ll notice that the Spirit does not mention the Rh-factor. This is because it was not discovered until 1940, the same year that this issue of the Spirit was published (so this issue was probably written and drawn before the Rh-factor was discovered).

That brings us back to question: What is type A-1 blood? As I see it, there are two answers — one “comic book reality” and one “real-world reality”.

I suspect the Spirit has discovered the Rh-factor on his own. Among his multitude of other skills, he has been shown many times to be a scientific genius. He has undoubtedly noticed that in addition to the ABO factor, there is an second important blood factor. He was able to isolate it and test for it. Instead of calling it “positive” or “negative”, it seems he just numbered it. Therefore, Mary’s type “A-1″ blood is really A- (since we know Mary has a rare blood type and A- is significantly less common than A+).

In the real world, the ABO factor tells us whether certain proteins are on the surface of a person’s blood cells. Type A has A proteins, type B has B proteins and so on. It turns out that there is more than one type of A protein. These subtypes are known as A1 and A2. So saying a person has type A1 blood simply means that they have A1 proteins on their blood cells. Of course, this was only discovered in the last decade, so it seems the Spirit may have been a man ahead of his times.

• A previous look at blood typing in Golden Age comics: Superman #6