3. Intercurrent has been known for some time that these (for instance, measles, tuberculosis) frequently bring out the symptoms of exudative diathesis, or aggravate them when they had already been present. Czerny explains thus, for instance, the appearance of the symptoms after vaccination.
We know, from old as well as recent experiences, that difficult dentition may have the same result, and this brings before us the question if we should not in this also regard the sensitive irritation as the principal causative factor.
4. Catching cold is regarded by Moro and others as a most impor tant etiological factor.
Relations of Lymphatic (and Exudative) Diathesis to These two conditions have been mixed up with each other a great deal in olden times as well as recently. Some of the older investigators, however, knew the difference remarkably well from their exact clinical observation; they, therefore, attempted to differentiate a prescrofular stage (Jiirg's "Skrofeln," Henke's "scrofular disposition") from the real disease ("Skrofelnkrankheit-scrofulosis" according to ,Thrg, "developed serofulosis" according to Henke). It was only after we had realized that scrofulosis represents a form of tubercular infection and after we had learned more exact methods of proving this (Koch, Pirquet and others), that we were able to follow up successfully its relation to lvm phatism. It was soon shown that the lymphatic constitution forms the soil upon which an accidental infection with tuberculosis will lead to the development of scrofulosis. The lymphatic diathesis is not so much (as we used to think) a special predisposing factor for the tubercular infec tion, as one which will rather influence the course of such an infection if it should arise accidentally. Escherich similarly expressed this con temporaneously and independently as follows: "Scrofulosis is that type of infantile tuberculosis which originates upon the soil of a lymphatic constitution." This is by no means the same as when Czerny calls scrofulosis "a combination" of exudative diathesis and tuberculosis and when he states that dietetic treatment can remove the former and thus change scrofulosis into tuberculosis, and further that this is the only result of the institutional treatment of scrofulosis.
As the inflammatory reaction is the most effective defense of the system, we will understand that tuberculosis will find less favorable ditions upon the soil of a lymphatic diathesis as this is especially posed towards inflammatory reaction; for this reason scrofulosis should be regarded as a relatively benign type of tubercular infection (Moro). Relations of the Lymphatic Diathesis to the Status condition which has been described as well as named by Arnold Paltauf, the occurrence and importance of which in childhood has been recognized by Eschcrich, will be described elsewhere in this work (Vol. III). Here we will only mention briefly that Heubncr, Escherich, Czerny, veer and others regard the stat us thymico-lymphaticus as closely related to the lymphatic diathesis and that they consider the former as a special type (perhaps to some extent an extreme type) or a part of the latter. Nothing definite is, however, known about this.
frequency of these constitutional abnormalities is very great : it is by far greater than that of manifest tuberculosis and it at least equals in infants that of rachitis, though it remains much longer in a florid stage than this latter disease. The manifestations frequently appear (luring the first three months of life, to persist beyond the puberty of the patient. In other cases puberty or even the end of the first decade will mark the turning-point. In adults we never observe the same symptoms which are so characteristic in childhood.
The urban population and of this again the upper classes are most severely and most frequently affected according to Comby; though it would appear as if statistics were so far of little use, owing to the indefi nite meaning which the term has had up to now.
Anatomy.—In so far as organic changes have been found at post mortem in the bodies of lymphatic children—in wasting diseases all its signs disappear—they are very similar to those found in the status thymico-lymphaticus (confer ibid.).