BIOLOGY. 271 



DISTRIBUTION OF COPPER IN THE ANIMAL KINGDOM. 



The presence of traces of copper in the blood of the lower ani- 

 mals has been for years an undisputed fact among chemists. In 

 the blood of the higher animals, however, with few exceptions, 

 no copper has been detected until lately. Wackenroder, for in- 

 stance, discovered this metal in the blood of the duck, but not in 

 that of the ox, the sheep, or the chicken. Its presence in the 

 blood and in the muscles of man has been asserted as often as it 

 has been denied, and now, as there is no doubt that it sometimes 

 occurs in the bile, and bile stones, and the liver of man, its exist- 

 ence in these organs is still considered to be merely accidental, 

 the more so as it is well known they retain poisonous substances 

 more than other organs. In 18G5, Mr. Ulex, in Hamburg, was 

 led to search for copper in various animals, with results which 

 gave rise to the supposition of a general distribution of copper in 

 the animal kingdom. As the tests for copper are very easy and 

 simple, as well as exceedingly sensitive, if properly ajDplied, the 

 respective investigations were extended by Ulex to animals of 

 various zoological classes. The reagents employed were tested 

 for copper in every case, and rejected if containing any. The 

 quantity ranged from 0.01 to 0.10 per cent. Among the mamma- 

 lia, it was found in the stomach and intestines of the European 

 and Canadian lynx, and in those of some species of the leopard, 

 jackal, and repeatedly in the flesh of horses and cattle. It was 

 met with in Liebig's meat extract, which contains the soluble por- 

 tions of beef in a concentrated form. Moreover, it was discov- 

 ered in the breast of a " crick duck," in the yellow and white of an. 

 egg, more so in the latter than in the yolk ; among amphibians, 

 in the geometrical tortoise, the viper, and frog. Among fishes, it 

 was met with in the eel and torsk, and among animals of the 

 lower classes in the following species : In Crangon vulgaris, the 

 South American bird-catching spider, Scolopendra Italica, in the 

 Spanish fly, the earth-worm and the ascaris, in the edible vine- 

 snail, in sea stars, in the thick-hided echinanthus, and in the bath 

 si)onge. It is thus seen that copper was detected in every case 

 where it had been searched for ; this having been the case with acci- 

 dentally chosen animals of various zoological classes, it may rightly 

 be concluded that the metal copper, like iron, is of a general distri- 

 bution in the animal kingdom. From tliis it follows that copper 

 must also be present in plants, in the groimd, and in the sea. In- 

 deed, copper was detected in plants by Meissner and John more 

 than 50 years ago, and later it was ascertained by Sarzeau to be 

 present in more than 500 vegetable species. In the earth, copper 

 has been repeatedly detected, and so in the water of the ocean. 

 If copper is found in the vegetable fibre, it follows that it must 

 also be present in its industrial products. In order to ascertain 

 this, Ulex selected a material that is daily employed by chemists, 

 and, on account of its purity, highly esteemed by them, namely, 

 Swedish filtering paper. Upon analysis it was found that 10 grains 

 of it yielded 6.03 grains or 6.3 per cent, of ashes, from which 



