A study is made of the maximum weight of spherical and cylindrical particles which can be supported by a pendant bubble and at an infinite fluid/liquid interface. The maximum weight increases with the radius, the contact angle (measured through the lower fluid), the density difference between the two fluids and the interfacial tension. It follows that to ensure good flotation suface active agents must be added to increase the contact angle. The maximum particle weight which can be supported at an infinite interface is always greater than that which can be transported there by the pendant bubble.

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