HISTORY.--Derived from the Greek [Greek: asthmatnô] to gasp for breath, the term asthma was employed by the older writers to designate a variety of affections of which embarrassed respiration was the most prominent symptom, thus including a great number of diseases which a more extended knowledge of pathology has since distributed among other nosological groups. By the earlier authors simple embarrassment of breathing was designated as dyspnoea; if attended with wheezing it was called asthma; while those forms in which the difficulty in respiration was so great as to prevent the patient from lying down were appropriately styled orthopnoea (Celsus). Ignorant to a great extent of pathological anatomy and unprovided with the improved methods of physical diagnosis which we now possess, they described as asthma not only the dyspnoea due to cardiac and pulmonary diseases, but also that occasioned by affections of the pleura and greater vessels. Covering such an extensive range of territory, it was found necessary to subdivide the disease into a number of varieties, each author classifying them according to his conception of the cause, seat, and nature of the trouble. Some of these--_e.g._ a. dyspepticum--still find a place in medical literature, but the vast majority of them, having ceased to be of any practical significance, have been discarded, and are now only interesting as examples of the crude and fanciful notions which prevailed in an age during which science rather retrograded than advanced.[1] Of the writers of this period, Willis in the seventeenth century is especially worthy of notice as being the first to describe the nervous character of asthma. Without discarding the accepted forms of the disease, he mentions another variety, characterized by spasmodic action of the muscles of the chest, to which he gave the name asthma convulsivum. [Footnote 1: "Van Helmont, discarding the ancient doctrine of the four humors, attributed asthma to an error of the Archeus, which he conceived to be enthroned in the stomach and to constitute the source of all diseased as well as of all healthy phenomena. This principle, he supposed, sent forth from the stomach a peculiar fluid, which, when it became diseased, gives rise to a morbid state of the parts to which it was conveyed. He moreover imagined that this fluid sometimes mixed itself with the male semen, and thus formed a compound which, as one of its constituents is the means provided by nature for the propagation of the species, possesses the power of generating a disease of hereditary character. Thus, when this compound was conveyed to the articulations, he affirmed it produced gout, and when it took its direction to the lungs it then occasioned asthma" (_Baltimore Med. and Surg. Journ. and Review_, Baltimore, 1833, p. 300).]