The card was produced by the Chillicothe, Ohio City Laboratory for recording milk characteristics, including sediment content, total milk solids, and number of bacteria cells (?) per cubic centimeter (cc). It appears that the batch of milk collected on August 10, 1944 was of questionable quality - earning a middling grade of 2 out of 5 with regards to sediment, but carrying a whopping 310,000 bacteria per cc (compared to 10,000 bacteria per cc recommended for "clean, rich milk" on the front). I'm not sure who George Rittenour was and why he sent this card to himself instead of just recording the information in a notebook, but I sure hope he flagged the batch.
You might wonder where all this sediment and bacteria is coming from. I would have wondered the same, until I spent a short spell milking goats on a farm a few years ago. Those damn goats constantly kicked dirt, straw, and even little goat turds into the milking bucket. We would just pick the debris out as best we could and pass the milk through a coffee filter before adding renet for cheese making. I doubt it would have received an A grade from the health department, but I never suffered any ill-effects from eating the milk and cheese during my time on that farm. Such experiences definitely gave me a sense that we are overly squeamish regarding food safety in this country. But I suppose it is nice to know that the good people at the Chillicothe milk department and others like it are keeping an eye on the supply for our benefit. And I'm sure I'll change my mind if/when I get food poisoning some day.