110 



SCIENCE. 



[N. S. Vol. III. No. 56. 



Especially important were the results ob- 

 tained on cleavage of the mucin with boil- 

 ing dilute acid (HCl). The presence of a 

 true carbohydrate group was plainly shown 

 by obtaining a well defined and crystalline 

 osazone by the phenylhydrazine test. The 

 osazone so obtained crystallizes in fine yel- 

 low needles usually arranged in rosettes. 

 When purified as much as possible the osa- 

 zone is readily soluble in warm water, alco- 

 hol, ether, chloroform and benzol. It melts 

 at 158°-160°C., and appears to resemble 

 very closely the peutaglucosazono obtained 

 by Hammarsten from the cleavage product 

 of the peculiar gluconucleoproteid described 

 by him as present in the pancreas. 



2. A. R. CnsHNY : The distribution of iron 

 in the Invertebrates. 



While the accumulation of iron in the 

 Vertebrates is generally supposed to be a 

 provision for supplying iron to the blood, 

 such an explanation will not hold for the 

 large percentage of iron in the hepato-pan- 

 creas of the Invertebrates, since in the latter 

 the blood contains only ti-aces of iron. The 

 hepato-pancreas of the Crustacea and the 

 Echinodermata shows about the same pro- 

 portion of iron as the Mammalian liver, 

 while the Mollusca have a much larger 

 accumulation than either. Muscle seems 

 to contain about the same percentage of 

 iron throughout the animal kingdom, and 

 in organisms without hepatic tissues, Such 

 as the Actinia, the percentage seems to ap- 

 proximate that of muscle. 



3. J. J. Abel : A preliminary account of 

 the chemical properties of the pigment of the 

 negroes shin. (With W. S. Davis.) 



This pigment is of importance, not alone 

 because it is a distinguishing characteristic 

 of the great majority of the human race 

 and because it may be found to serve a 

 physiological purpose, but also because of 

 its very probable relationship to the pig- 

 ment more sparingly deposited in the skin 



of the so-called white races and to that 

 found in the hair. 



It may also be found related to the pig- 

 ment of the skin in certain pathological 

 conditions, as in the bronzed skin of Addi- 

 son's disease, or in the brown or black 

 patches known as naevi spili. 



The authors have succeeded in isolating 

 the coloring principle of the negro's skin 

 and they hope to apply their method to 

 other instances of skin pigmentation. The 

 isolated pigment has not yet been obtained 

 entirely free of mineral constituents. After 

 incineration the resulting ash consists 

 mainly of silicon dioxide; a very little iron, 

 amounting to 0.1% or less of the original 

 weight of substance, is also present. 



At present the authors are attempting to 

 determine the composition of the pigment 

 granules, the minute anatomical elements 

 found in the lower epidermal cells which 

 contain the pigment in union with other 

 substances. While as yet unprepared to 

 give quantitative results, they are con- 

 vinced that these black granules contain 

 very much inorganic matter, iron being 

 present in considerable amount. 



The isolated pigment is found to be 

 very resistant toward destructive chemical 

 agents. Freshly precipitated it is soluble 

 in water, in alcohol (90%) and in mixtures 

 of alcohol and 6ther. In its behavior to- 

 ward mineral acids, alkalis and the agents 

 employed to precipitate proteids and also 

 toward oxidizing agents, it agrees with the 

 dark pigments that have been obtained 

 from the hair, from the choroid coat of the 

 eye and from melanotic tumors; in short, 

 it must be grouped with that ill-defined 

 class of compounds known as melanins. 



The pigme"nt contained in the hair of the 

 negro was also isolated and was found to 

 respond ia a like manner to the many 

 chemical tests to which it was subjected. 

 Ultimate analj'ses of the skin and the hair 

 pigments also showed a close agreement. 



