ETIOLOGY.—Numerous writers have expressed a doubt whether a spontaneous acute peritonitis ever occurs, or if it is ever primary its occurrence in this way is very rare. Habershon1 has presented the case with more apparent force than any other writer. He studied the record of five hundred autopsies of peritonitis made at Guy's Hospital during twenty-five years, but he "cannot find a single case thoroughly detailed where the disease could be correctly regarded as existing solely in the peritoneal serous membrane."

1 Medico-Chirurgical Trans., vol. xliii. p. 5.

This statement must be received with some caution. In twenty-five years the records were probably made by a number of different persons, and persons of varying views and varying capacity and judgment. It is possible that the quotation may embrace some of the changes already referred to as the consequences of peritonitis. It does embrace the cases "when inflammation of the serous membrane occurs in the course of albuminuria, pyæmia, puerperal fever, erysipelas, etc." It also includes "peritonitis caused by general nutritive changes in the system," as seen "in struma, cancer, etc.," "comprising also those cases in which the circulation of the peritoneum has been so altered by continued hyperæmia (modifying its state of growth) that very slight existing causes suffice to excite mischief, as in peritonitis with cirrhosis, disease of the heart, etc."

With these explanations the statement differs widely from what it would seem to mean without them. It is far from saying that peritonitis always follows some abdominal lesion and is caused by that lesion.

Habershon's paper was published twenty-three years ago, and during all these years the curative treatment of peritonitis, to which the paper itself gave currency, has enabled us to study our cases after recovery as well as before the sickness, and it can hardly be doubted that a much larger proportion of the cases are primary and idiopathic than either Louis or Habershon found reason to admit. That a large number are produced by preceding lesions and constitutional conditions no one will be likely to doubt.

Among the 500 post-mortem examinations of peritonitis reported by Habershon, he found preceding disease or injury recognizable in the abdominal cavity in 261. The following is his table, viz.:

From hernia, of which 19 were internal obstruction102
From injuries or operations35
From perforation of the stomach, ileum, cæcum and appendix, colon, etc. (other 13 mentioned with hernia, or with cæcal disease)43
And leading to fecal abscess (2 otherwise mentioned)17
From typhoid ulceration without perforation5
From disease or operation on bladder and pelvis, viscera, etc.42
From disease of the liver and gall-bladder11
From acute disease of the colon (3 others enumerated with perforation)3
From disease of the cæcum or appendix (9 others previously mentioned) 3
261

Habershon says that in the (his) second and third divisions of the cases the causes were as follows:

From Bright's disease63
From pyæmia, 13; erysipelas, 5; puerperal fever, 10; with pneumonia, 331
From strumous disease70
From cancerous disease40
From hepatic disease27
From heart disease 9
240

I have drawn thus liberally from Habershon's paper because it is the only paper that I know, in any language, founded on the analysis of a large number of cases (for five hundred post-mortem examinations is a large number for a disease no more frequent than peritonitis), in the belief that he dealt with facts and that his conclusions must be of great value. He may differ with other physicians regarding what constitutes strumous disease and in the agency of heart disease. He may have mistaken coincidence for consequence, but the paper bears the marks of honesty and good faith from the beginning to the end.