yet to preserve a certain period, such, for example, as to extent of diastole, if there are two great and one small, then again two great and one small, and so on successively, such a pulse would be called anomalous, that is to say, unequal, but regular. But, if it not only had no equality, but likewise no order in its inequality, such a pulse would be not only unequal, but also irregular, and in like manner with regard to the other kinds. Of the irregular, some are altogether so, observing no period whatever; others are indeed regular as to periods, but, having no continued order, they may in this respect be called irregular, but in so far they observe a certain period regularly, they being regulated as to their periods. As if, for example, there were two great and two small, then three great and three small, and four great and an equal number small; and, returning again, two great and two small, three great and as many small, and so on in like manner. It is to be remarked that, of all the other opposite kinds, there is one intermediate between the two extremes, but that there is none between the equal and unequal, and the regular and irregular, unless you choose to call the one which is regular as to periods the medium between the regular and irregular. And the intermediate pulses of all the other kinds are the natural, except that which relates to strength and weakness, as we showed. But, in those we have been describing, the equal alone is the natural, and all the others are not natural, namely, the unequal, the regular, and the irregular. These are all the kinds of pulses and their generic differences. Some add two others to these, the one in regard to the position of the artery, according as it seems to be carried upwards or downwards, to the right or to the left, and the other in regard to the times of expansion. But these we treated of along with the undulatory and vibratory. And we, for the sake of brevity, have only delivered the simple varieties; but, from what has been said, one may easily connect them, and discover those which arise from their combinations.