Don't eyeball out 2C-E. The dose-response curve is too steep, you could end up having a very difficult trip if you accidentally eyeball a dose too big, which is very easy to do.
Phenethylamines, such as 2C-E are fairly stable so what you should do is dilute the 2C-E in a mixture of distilled water and ethanol, such as vodka. Make a mixture of 20 ml with 2/3 distilled water and 1/3 ethanol/vodka. Weigh out 100 mg of your 2C-E (that is 0.10 on your scale, yes) and dissolve the 2C-E in the liquid. You now have a solution of 5 mg 2C-E for ever 1 ml of liquid. Use a needless syringe to dose out however many mg you would like to do. 5 mg equals 1 ml, 10 mg equals 2 ml, 15 mg equals 3 ml and so forth.
Liquid Measurement Thread
http://www.bluelight.ru/vb/showthread.php?t=286239
2C-E Storage and Solubility
http://www.bluelight.ru/vb/showthread.php?t=399328