There can be no doubt but the general interest in public health, and the absolute necessity of every one using his reason and judgment to guard against disease, will render this little book very welcome. The numerous facts brought together will not be without value to even the most critical. For our part we should not like to subscribe to some of the propositions, but these propositions are defective rather because the author has not investigated closely some of the parallel fields of study, than because his main proposition that underdraining is useful, is incorrect. It is scarcely correct to say as he does, that "Physiologists have not told us why the holes in a flower pot are so essential to the health of a plant." They know why, and the}' tell why. They know and they teach, that certain plants must have the atmosphere in the soil in order to feed properly; and that there can be no air in a waterlogged soil. The author might find this explanation in any practical work on vegetable physiology, but not having searched this far, and believing without search, that physiologists have said nothing about it, he gives as "perhaps the only explanation that plants secrete a poisonous excrement, which, unless removed by percolating water, poisons the plants themselves." As we have often said in relation to other questions, it is no advantage to a good cause to be supported by a bad argument; and it is because we wish well to the cause advocated by the author with good effect in most parts of the work, that we point out its weakness here.

Much attention is given to the drainage of cities as a question of health. The great trouble in all these questions is the want of reliable facts. It is said that the water from the Delaware and the Schuylkill rivers is so polluted by the drainage into them as to breed disease from drinking the water in the cities. It ought not to be so polluted - at any rate people want to get the water as pure as they can - and yet the figures show that the average health of Philadelphia is quite as high as of the people outside who drink spring water.

For all this, purity of air and purity of water should ever be an aim with all. We can never err on the side of cleanliness or freedom from noxious odors. There is no doubt but Dr. Wilson's work will do much to further these good ends, and it will, we trust, have a good sale.