Postal History of the Spanish Civil War and the Second Republic: A Most Unusual Cover

I was going to continue writing on the Second Republic transition and República Española overprints period, but I picked up this “cover” recently and it may be one of the most unusual items I have run across. It is a small envelope, not unlike those we use at some parks where you place the parking fee in it and deposit in a park ranger slot.

The small envelope was used to for doses of cowpox anti-serum. The envelope’s return address was Laboratorio SERAS, Oriente, 7-Sevilla. It is indicated the cost of two doses of anti-cowpox vaccination was 3 ptas with stamps included. The front has a date stamp of 9 Feb, 1937

On the reverse are two stamps-one a bisected 30c Edifil #823 (can’t tell if is a variety) and a 5c. Edifil #816Aa sepia with 10mm imprint. Both stamps are overprinted with a hand stamp 9, Feb1937. I am not sure if this was sent through the post thought I doubt it as there is no regulation postal mark.

What do we know about Laboratorio SERAS. This lab was an important lab for producing rabies, and cowpox for example. The lab was founded by Dr. Antonio de Seras y González, a native of Huelva, was trained at the Pasteur Institute in Paris. Following his training he moved to Sevilla where he eventually took over the Provincial Institute of Hygiene in 1896. During the war the he was persecuted for being a Mason,

“The case of Antonio de Seras, doctor, veterinarian and Sevillian mason, is very illustrative. His son, of the same name, remembers how his father was saved from being shot "because Queipo de Llano was a close friend of the family". Even so, like many, he had to live in the interior exile of the outlaw: "They took away the presidency of the College of Veterinarians and I remember how I went with him to the police station, where he had to show up every week because he was forbidden to leave Seville," he recalls. Antonio "My father died when I was a student, and he was always very reserved to talk about these things but I remember that when my mother and he celebrated their silver wedding they could not repeat their honeymoon because they did not give him a passport; that hurt him a lot and he never forgot ", he concludes. The price of being different in a Spain painted with blood and a single stroke law.”

(https://www.redaccionmedica.com/la-revista/reportajes/medico-y-perseguido-en-la-guerra-civil-3073)