Reddit mentions of Frontier Natural Products 2708 Camphor Granules 0.5 lbs.

I'm making Storm Glasses this year for some people ... you can do quite a few for < $100

recipe: http://chemistry.about.com/od/weirdscience/a/fitzroy.htm

Ingredients for Storm Glass

• 2.5 g potassium nitrate
  
• 2.5 g ammonium chloride
  
• 33 mL distilled water
  
• 40 mL ethanol
  
• 10 g camphor
  
  Dissolve the potassium nitrate and ammonium chloride in the water; add the ethanol; add the camphor. Place in corked test tube.
  
  Where to get Chemicals
  
  https://secure.sciencecompany.com/Default.aspx
  http://www.amazon.com/Frontier-Natural-Brands-Camphor-Granules/dp/B000UYIQYI
  
  Where to get glass
  
  http://www.collectingwarehouse.com/Product-Home-Page/Glass-Domes (these are a pain to secure the base to the glass - tried using marine epoxy... didn't come out so great)
  
  http://pilotvials.com
  
  Here's a public Google Spreadsheet Template to help with measurements since you'll likely want more or less than the recipe makes:
  
  https://docs.google.com/previewtemplate?id=0Asv4qOCYhthXdHdyS3hrY2RHQXcxNi1hdHJvQWU5OVE&mode=public
  
  

This (upvote the original author!) was posted the other day in a similar thread and looks amazing.

Quoted here for the lazy:
>I'm making Storm Glasses (Wikipedia: Storm Glass) this year for some people ... you can do quite a few for < $100

>Recipe:

>Ingredients for Storm Glass:

> 2.5 g potassium nitrate
> 2.5 g ammonium chloride
> 33 mL distilled water
> 40 mL ethanol
> 10 g camphor

> Dissolve the potassium nitrate and ammonium chloride in the water.
> Add the ethanol.
> Add the camphor.
> Place in corked test tube.

>Where to get Chemicals:

> Science Company
> Amazon (Camphor Granules)

>Where to get glass:

> Collecting Warehouse (these are a pain to secure the base to the glass - tried using marine epoxy... didn't come out so great)
> * Pilot Vials

>Here's a public Google Spreadsheet Template to help with measurements since you'll likely want more or less than the recipe makes.

I cleaned up the formatting a bit so it's easier to read but all credit goes to wiseleyb for this comment.