570 



SCIENCE 



[N. S. Vol. XLII. No. 1086 



be ready for occupancy in about a year and 

 a half. The cost of the buildings wUl be 

 about half a million dollars. 



The department of pharmacy of the Oregon 

 Agricultural College has been notified of its 

 acceptance as a member of the American Con- 

 ference of Pharmaceutical Faculties. 



The will of the late Mr. George May, min- 

 ing engineer and colliery proprietor, of Dar- 

 lington, bequeaths £500 to the North of England 

 Institute of Mining Engineers, the income to 

 be applied in providing " George May " prizes 

 for students, and 500Z. to Armstrong College, 

 Newcastle, to found a " George May " scholar- 

 ship in mining. 



Professor Herbert Couper Wilson", of 

 Carlton College, has been appointed visiting 

 lecturer in astronomy, at Harvard University. 

 Marshal Eabyan has been promoted to be as- 

 sistant professor of comparative pathology. 



DISCUSSION AND COEBESPONDENCE 

 parasites of the muskrat 



In a recent number of the Journal of Para- 

 sitology,^ Professor Al. Mrazek, professor of 

 zoology, Bohemian University, Prague, called 

 the attention of American helminthologists to 

 the opportunity for study of the parasites of 

 one of the most typical North American mam- 

 mals. 



We announced in a recent number of Sci- 

 ence- the finding of a varied and abundant 

 parasitic fauna in muskrats in Nebraska and 

 called attention to the important, virgin and 

 fertile nature of this field for the parasitologist 

 and the need and value of a thorough survey 

 of the parasitic fauna of our common North 

 American animals. 



A study of the parasites of the muskrats, 

 now practically completed, gives the following 

 data. In forty-two muskrats, 881 parasites 

 were found. No parasites were found in four 

 muskrats, three harbored cestodes, trematodes 

 and nematodes and three harbored a single 

 species of trematode. The parasites found 

 represent nine species of trematodes, of which 



1 1914, Vol. No. 2, p. 104. 

 2 1913, Vol. 37, p. 268. 



three belong in the genus Echinostomum and 

 one in each of the following genera, Echino- 

 paryphium, Notocotyle, Catatropis, Plagi- 

 orchis, Hemistomum, and a new genus 

 Wardius. Two species of cestodes were found 

 belonging in the genera Hymenolopis and 

 Anomotaenia and three species of nematodes, 

 belonging in the genera Trichiurus, Triclio- 

 strongylus and Capillaria. The description of 

 these parasites is given in the June number of 

 the Journal of Parasitology, Vol. 1, No. 4. 

 Pranklin D. Barker 

 The University op Nebraska 



THE chemical composition OF BORNITE 



In Science for September 17, 1915, Professor 

 Austin P. Rogers admirably summed up the 

 evidence as to the composition of bornite, and 

 concluded that the best explanation of the 

 known facts is that the mineral consists of a 

 solid solution of varying amounts of chalcocite, 

 Cu,S, in a normal bornite, Cu^FeSj. The ob- 

 ject of this note is to bring forward another 

 possible interpretation. 



Since chalcocite is of common occurrence 

 as inclusions in bornite the assumption that it 

 may unite with the latter in solid solution is a 

 reasonable one. But inclusions of chaleopyrite, 

 CuFeS,, and even of pyrite, FeS„, are likewise 

 frequently found, so it can not be denied that 

 these minerals may also form solid solutions in 

 the bornite. The clustering of analysis points 

 in the diagram around Cu^FeSj may then be 

 accepted as " evidence that [normal] bornite 

 has the formula Cu^FeS^ " without excluding 

 the possibility of solid solution, because the 

 analyses lying in the diagram to the left of 

 the Cu^FeSj point may well be those which con- 

 tain the chaleopyrite in solid solution, the ab- 

 sence of analyses far to the left of the CujFeS, 

 point indicating that this is the limit of solu- 

 bility of chaleopyrite in bornite : Cu^FeS^ + 

 CuFeS, = 2Cu3FeS3. The entrance of pyrite 

 in solid solution would also account at least 

 in part for those analyses lying above the 

 diagonal line, and it need not be assumed that 

 they are erroneous. 



There is, however, another way of explaining 

 variability in composition of the type shown 



