What was this used for?

[tekyma]

Hi All,
I have a couple of these bottles from my father-in-laws estate. I am not sure what they are. The top has a channel to let some type of liquid out I think.

Thanks in advance for your help - you guys are the best!

tekyma

 

[botlguy]

I believe they are for dispensing chemicals, like acids and caustics, by the drop in a laboratory. Could be for other liquids but I believe that is the main purpose.