Sentence:  Obviously , if colloidal particles bear <WSD>charges</WSD> of opposite sign or , if one kind is charged and the other kind is not , the attraction will be intensified and the tendency to agglomerate will be greatly reinforced . 
Meaning of the word marked with <WSD> tags:  the quantity of unbalanced electricity in a body (either positive or negative) and construed as an excess or deficiency of electrons