This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
Patent plasters, such as adamant, etc., are not often employed for private dwellings, being chiefly suitable for mercantile purposes. The patent plaster has certain advantages that are self-evident - such as quick drying and hardening. Its surface hardens more quickly and resists abrasure longer than the ordinary lime plastering However, a break once occurring, the extreme stiffness of the mixture makes it liable to extend further and to be of a more serious nature than if the softer, more flexible lime plaster covering had been injured in the same manner.
The extra stiffness of most patent plasters is caused by the cement that generally forms an important part of their composition. These plasters are sold ready for use, requiring merely the addition of a sufficient amount of water. They are therefore especially adapted for use by the inexperienced, and are valuable for executing small pieces of work, as they do not present the liabilities to failure, or loss of time and delay, occasioned by mixing up batches of lime mortar.