III. The head just now finished includes really by far the greatest portion of the economy of study. There are various other devices of importance in their way, but much less liable to error in practice. Of these, a leading place may be assigned to the best modes of Distributing the Attention in reading. Such questions as the following present themselves for consideration to the earnest student. How many distinct studies can be carried on together? What interval should be allowed in passing from one to another? How much time should be given to the art of reading, and how much to subsequent meditating or ruminating on what has been read? These points are all susceptible of being determined, within moderate limits of error. As to the first, the remark was made by Quintilian, that, in youth, we can most easily pass from one study to another. The reason of this, however, is, that youth does not take very seriously to any study. When a special study becomes engrossing, the alternatives must rather be recreative than acquisitive; not much progress being made in what is slighted, or left over to the exhaustion caused by attention to the favourite topic. A more precise answer can be made to the second and third queries, namely, as to an interval for recall and meditation, after putting down a book, and before turning the attention into other channels. There is a very clear principle of economy here. We should save as far as possible the fatigue of the reading process, or make a given amount of attention to the printed page yield the greatest impression on the memory. This is done by the exercise of recalling without the book; an advantage that we do not possess in listening to a lecture, until the whole is finished, when we have too much to recall. To hurry from book to book is to gain stimulation at the cost of acquisition. I have alluded to the case of an engrossing subject, which starves all accompanying studies. There are but two ways of obviating the evil, if it be an evil; which it indeed becomes, when the alternative demands also are legitimate. The one is peremptorily to limit the time given to it daily, so as to rescue some portion of the strength for other topics. The other is to intermit it wholly for a certain period, and let other subjects have their swing. In advancing life, and when our studious leisure is only what is left from professional occupation, two different studies can hardly go on together. The alternative of a single study needs to be purely recreative.