MF.NfOKIAL OF A. A. JILIEN 



83 



West Indies, and visited the islands of Bonaire, Curagoa, and Aruba, 

 West Indies, making a study of the guano resources and of their general 

 geology. At the commencement of 1882 the degree of Doctor of Philos- 

 ophy was conferred upon him by Xew York University. 



During this period Dr. Julien was also preparing an extremely im- 

 portant report for the Tenth United States Census, on "The durability 

 of building stones in New York City and vicinity," which is published 

 in volume X of its reports. This larger report was suggested by several 

 sliorter contributions, cited in the bibliography ])elow, and in the end led 

 to the investigation of the causes and cure of the alarming disintegration 

 of Xew York's priceless relic of antiquity, the Egyptian ol)elisk, one of 

 the features of Central Park. In these early years of the decade of 

 the eighties, Dr. Julien became interested, along with his friend tlie late 

 H. Carrington Bolton, in the curious musical note given out by certain 

 beach-sands under the pressure of footsteps, a note which has attached 

 to them the name "singing sands." A very extensive collection of sands 

 from, one might almost say, all over the world was made for investiga- 

 tion and several contributions resulted on their microscopic cliaracters. 

 Soon afterward Dr. Julien took up the study of the two species of sul- 

 ])hi(le of iron, pyrite, and marcasite, especially with regard to their de- 

 composition, and several papers were published which have been much 

 (juotefl. While many geologists were more or less thoroughly convinced 

 of the organic nature of Eozoon canadense. Dr. Julien's petrographic 

 studies led him very early to the conclusion that it was a purely inor- 

 ganic product of contact metamorphism ; but his interest became excited 

 in the development of serpentine, and continued active all the rest of his 

 life. Years afterward he brought out the importance of brucite, dewey- 

 lite and some minor transition ])roducts, and serpentine became the sub- 

 ject of his later labors. He had prepared a manuscript embracing tlie 

 results of many years of reading and investigation, which was unfor- 

 tunately destroyed in a firo which consumed his home, just a week before 

 his death. 



Having become transferred in 1808 from the Department of Chem- 

 istry in Columbia University to the Department of Geology, at tlie time 

 the university removed to its present site, he entorod into the discussions 

 which were active in the meetings of the officers and students of the 

 latter. Among these the recasting of the analyses of rocks was one. 

 Prmnpted by his studios of the serpentines. Dr. .Julien was led to applv 

 the methods of recasting to tlie analyses of a varietv of doubtful >p('( j.-- 



