Cobalt Glass X Pattern on Base and a #1

[Vetus Vitrum]

7 1/4" x 3 1/2" x 2 1/2" just a decent size blue bottle with no markings except a 1 on the base. The tell might be the X shaped impression on the base. I kinda like that it is unmarked but it drives me crazy not to e able to date it or know who made it, much less what was in it. Any info is greatly appreciated. You know what I like about collecting bottles? I'm getting older and I'm single but I can tell folks I'm always dating.

 

[CanadianBottles]

Based on the shape it's probably a milk of magnesia from the mid-20th century. Likely not Philips but one of their competitors.