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SCIENCE 



[N. S. Vol. XLIV. No. 1126 



intestine and enlargement of the spleen in 

 that slow nervous fever which we now 

 recognize as typhoid. The effect of this dis- 

 ease in producing a cloudiness or aberra- 

 tion of the mind is what has given it its 

 name, which is derived from the Greek rl^os 

 or cloud. Its particular nervous or mental 

 effect was further observed by Huxham, 

 who in 1737, on a purely symptomatic basis, 

 separated cases of "putrid malignant 

 fever" (or typhus) from the "slow nervous 

 fever." The final separation of these two 

 confused diseases did not come, however, 

 mntil a century later and was dependent not 

 •only on the recognized differences in the 

 •contagiousness and course of the two dis- 

 eases, but on the recognition of the char- 

 acteristic and almost inevitable lesions or 

 anatomical changes which are found in 

 fatal cases of typhoid, but never in typhus 

 fever. These lesions, ulceration of the in- 

 testine and swelling of the spleen, liver and 

 lymph nodes, mentioned by Strother, were 

 described by Riedel in Germany (1748), 

 Baillie in England (1761) and in particular 

 by Roderer and Wagler (1762). We owe 

 further descriptions of the clinical char- 

 acteristics of typhoid fever to Bretonneau 

 (1826) who called it " dothienenteritis, " or 

 abscess of the small intestine, a name which 

 it frequently bears in French literature, 

 and to Louis (1829) who gave the name 

 "fievre typho'ide" to the malady. 



It is to the great credit of a Philadel- 

 phian, William Gerhard, to have given in 

 1839 a convincing basis of separation be- 

 tween typhus and typhoid fevers. He based 

 this differential diagnosis on accurate de- 

 scriptions of the greater contagiousness of 

 typhus, the presence of characteristic lesions 

 in typhoid, and on careful comparison of 

 symptomatic differences between the two 

 maladies. His observations, later confirmed 

 in Germany and England, gave us the first 

 basis on which to regard typhoid fever as a 

 separate and distinct disease entity. 



The final chapter in the clinical or purely 

 observational study of typhoid fever is rep- 

 resented by two important observations in 

 reference to its transmission from one hu- 

 man being to another. The disease as con- 

 trasted with typhus fever was regarded, 

 and properly so, as only slightly contagious., 

 that is, directly transmissible from one pa- 

 tient to another. In 1856 Budd pointed out 

 that the danger of transmission in typhoid, 

 the poison of the disease as he expressed it, 

 lies in the patient's excreta, and in 1873 

 Murchison actually traced an epidemic to 

 a contaminated milk supply, and showed 

 that the stools of typhoid patients are the 

 principal source of danger in spreading 

 the disease. 



This brief statement then outlines the 

 significant advances that were made over a 

 period of centuries in the differentiation 

 and recognition of typhoid fever by purely 

 observational methods, confined to the pa- 

 tients themselves and made by practitioners 

 of medicine. In so far as alleviation of the 

 disease is concerned, there is little or noth- 

 ing to report beyond purely symptomatic 

 and palliative treatment, the most signif- 

 icant point in which was the introduction 

 of hydrotherapy by James Currie in 1770 

 and its rediscovery by Brand a century 

 later. The recognition of the danger of 

 spreading the disease through contamina- 

 tion with typhoid excreta must be regarded 

 as a great contribution to preventive medi- 

 cine. 



We come now to a period, which may be 

 roughly defined as the year 1880, which 

 ushered in the two most productive of the 

 medical sciences, bacteriology and its twin 

 sister, immunology. Whereas the experi- 

 mental sciences of chemistry, physiology, 

 and some aspects of experimental pathology, 

 were already established and had made, and 

 continued to make, valuable contributions 

 to human welfare, bacteriology was destined 

 to explain the causation of a series of dis- 



