They Cracked This 250 Year-Old Code, And Found a Secret Society Inside
I suspect there's a second code hidden in there. From the article, describing the code symbols that are Roman letters:    These unaccented Roman letters appeared with the frequency 
    you’d expect in a European language. But they don’t 
    represent letters—they mark the spaces between words.

It's implausible that these characters just happen to appear with a language-like frequency distribution and are all meaningless spaces. I suspect they actually have a meaning and provide a second message.To clarify, it's like taking "SthisEisCtheRfirstEmessageT" and assuming all the capitals just indicate spaces.