Old bottle found.

Hello! I found a bottle while digging in my backyard for a boiler room foundation, and i would like to learn more about it. Found it at aprox. 50 cm from the surface, and it had some kind of gooey,black substance in it. I am from Romania, tus i think it is of romanian or russian origin.Around it's neck, there is a band made of tar (i think).It could be a medicine bottle from the WWI? I've attached some images with it. Thank you in advance.

P.S: The bottle-cap is made by me, just for the visual appearance.

Here is the image gallery: http://imgur.com/a/9JKpR/#0