MORPHIN-LIKE SUBSTANCES. 243 



ing becomes a brick-red, and in more concentrated solution fire red. 

 Both indigo red and indigo blue may be formed by oxidation of indol. 



Knowing that indol and its derivatives are formed in anaerobic 

 putrefaction, and that in Dragendorff's scheme for the separation 

 and identification of vegetable alkaloids, these substances appear in 

 the residues which are tested for morphin, and knowing the great 

 number and variety of color reactions given by these substances, it 

 may be asked. How much reliance can be placed on the color tests 

 for morphin? Besides the indol bodies, other substances are formed 

 in the anaerobic putrefaction of proteid bodies and among these are 

 certain aromatic products of the putrefaction of tyrosin. The fol- 

 lowing may be mentioned : (1) Hydroparacumaric acid (paraoxy- 

 phenylpropionic acid). This substance gives with ferric chlorid a 

 distinct but evanescent blue coloration. (2) Paraoxyphenylacetic 

 acid. This substance gives with ferric chlorid a pale grayish-violet, 

 which soon changes to a dirty green color. 



Among other products of anaerobic putrefaction of proteids, phenol 

 and parakresol may be mentioned ; with the former ferric chlorid 

 gives a violet color and with the latter a blue. 



In the case of Dr. Urbino de Freitas ^ of Oporto, Portugal, who 

 was accused of attempting the wholesale murder of his wife's family 

 by the administration of morphin, the toxicologists relied for the de- 

 tection of this alkaloid upon the color reactions applied to residues 

 obtained by following Dragendorff's method. They also reported 

 the presence of narcein and the probable presence of delphinin. 

 The defense questioned the reliability of the tests used and a large 

 number of the most prominent toxicologists in Europe became in- 

 volved in the controversy. It was claimed by the prosecution that 

 200 mg. of -morphin had been recovered. On this point Beckurts 

 stated that it was incomprehensible to him that a toxicologist should 

 recover 200 mg. of morphin and not be able to present a part of it 

 in evidence, and also to furnish a portion to the experts on the other 

 side. Brieger and Bischoff thought 200 mg. a fabulous quantity to 

 recover and that a portion of the poison should have been presented 

 in evidence. Husemann thought the tests relied upon insufficient, 

 and that putrefactive substances had been mistaken for the vegetable 

 alkaloid, and even Dragendorff himself thought it likely that this 

 mistake had been made. For the detection of the morphin the toxi- 

 cologists for the prosecution had relied chiefly upon the application 

 to the amylic alcohol residue of the tests with iodic acid, Frohde's 

 reagent, and sulphoselenic acid (known as Lafon's reagent). The 

 chemists consulted quite generally agreed that these tests are unreli- 

 able and that the amylic alcohol extract of putrefying material fre- 

 quently responds to these tests when morphin is known not to be 

 present. 



' Station medieo-legale de I' affaire Urbino de FreUas. 



