52 



SCIENCE. 



[N. S. Vol. V. No. 106. 



field of work whicli occupied Banmann's 

 attention during his entire life. The ob- 

 servation that phenol bodies constantly 

 present in the urine are not derived from 

 the aromatic substances in the vegetable 

 foods was followed by the important discov- 

 ery that these bodies are excreted combined 

 with sulphuric acid in the form of ethereal 

 sulphates. With the isolation of these 

 compounds (e. g., phenyl- and cresylsul- 

 phates) there was introduced into physiol- 

 ogy the knowledge of a new class of syn- 

 theses in the organism, comparable to the 

 well known synthesis of hippuric acid. 

 The finding of phenol as a putrefaction prod- 

 uct of proteids led to the announcement 

 that the aromatic substances of the urine 

 largely owe their origin to the putrefactive 

 decomposition taking place in the alimen- 

 tary tract. The products, many of them 

 strongly toxic, are absorbed and reappear 

 in relatively harmless combination with 

 sulphuric acid. Ethereal sulphates were 

 shown to be absent in the uriue when in- 

 testinal putrefaction is totally suppressed, 

 and physiologists have come to look upon 

 the quantity of combined sulphuric acid ex- 

 creted as the best indication of the inten- 

 sity of the decomposition iu the intestine. 

 The so-called ' indican ' of the urine was 

 also drawn within the scope of these inves- 

 tigations and was shown to be quite distinct 

 from the vegetable glucoside indican, al- 

 though yielding indigo on oxidation. After 

 Jaffe had demonstrated that the chromogen 

 of the urine is derived from indol, Baumann 

 and Brieger proved that it is in reality an 

 ethereal compound of indoxyl with sul- 

 phuric acid, analogous to those already 

 mentioned. It is scarcely necessary to re- 

 mark that these discoveries have had a far- 

 reaching influence on practical medicine. 



The behavior of sulphur compounds in 

 the animal organism was another favorite 

 theme to which Baumann and his pupils 

 contributed extensively. The study of the 



compounds of mercapturic acid which can 

 be obtained under appropriate conditions 

 in the urine, yielded the proof that there 

 is formed in intermediary proteid metabol- 

 ism an atom-complex closely related to the 

 organic sulphur compound cystin, excreted 

 as such in the rare cases of so-called cysti- 

 nuria. It was shown that the cj'Stin is ac- 

 companied under these circumstances by 

 at least two diamines (putrescine and ca- 

 daverine) which are found in both urine 

 and fffices. The peculiar perversion of 

 metabolism known as alcaptonuria was 

 also shown to owe its peculiarities in many 

 instances to a dioxyphenylacetic acid, the 

 synthesis of which was accomplished in the 

 Freiburg laboratory. 



Among Baumann's pharmacological in- 

 vestigations may be mentioned in par- 

 ticular his researches on the sulfones, which 

 led to the discovery of several widely used 

 hypnotics : sulfonal, trional, etc. Together 

 with Kast and others he studied their 

 physiological action and demonstrated that 

 only those are effective which ai-e trans- 

 formed in the body, the intensity of their 

 action being dependent upon the number of 

 ethyl groups present. 



Scarcely more than a year ago the finding 

 of iodine as a normal constituent of the 

 animal body and the isolation of thyroiodin 

 (iodothyrin), the physiologically active 

 substance of the thyroid glands, aroused 

 the interest and admiration of the medical 

 world. Baumann was actively engaged in 

 the solution of many problems suggested 

 by this last great discovery when, after an 

 illness of only two days, death put an end 

 to a brief but brilliant career. 



It is impossible iu a brief sketch to give 

 more than an outline of some of Baumann's 

 contributions to physiological chemistry. 

 His loss will be felt not alone by chemists, 

 but also in the broader circle of investiga- 

 tors in scientific medicine ; for Baumann 

 exercised a wide influence as a teacher, as 



