Filter paper, qualitative
Qualitative filter paper, Grade 1573½, folded filters
Qualitative filter paper, Grade 1573½, folded filters
Qualitative filter paper, Grade 1573½, folded filters
Qualitative filter paper, Grade 1573½, folded filters
Qualitative filter paper, Grade 1573½, folded filters
Qualitative filter paper, Grade 1573½, folded filters
Qualitative filter paper, Grade 1573½, folded filters
Qualitative filter paper, Grade 1573½, folded filters
Qualitative filter paper, Grade 593 ½, folded filters
Qualitative filter paper, Grade 593 ½, folded filters
Qualitative filter paper, Grade 593 ½, folded filters
Qualitative filter paper, Grade 593 ½, folded filters
Qualitative filter paper, Grade 594½, folded filters
Qualitative filter paper, Grade 594½, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters
Qualitative filter paper, Grade 595 1/2, folded filters