Jan. 1935 Annual Report of the Director 197 



of Mesozoic Age. This is a collection of approximately a thousand 

 excellently preserved specimens obtained at different times from 

 several sources. The best part of it, recently collected by Assistant 

 Patterson, has never been named, and for much of the older material 

 identification is doubtful or absent. 



Dr. Alfred Walcott, working in the Department under a special 

 arrangement, began a detailed study of a peculiar deposit of diamond 

 in a hard matrix of lazulite and cyanite on specimens collected by 

 Dr. B. E. Dahlgren, Curator of Botany, in Brazil. This is an 

 important research as it may throw some light on the puzzling 

 question of the origin of the diamond. 



During an extended leave of absence Assistant Patterson made 

 studies of vertebrate fossils in the British Museum of Natural 

 History and the Museum of the Royal College of Surgeons in London 

 for comparison with specimens now being studied in the Department. 



Tests and analyses required for identifications of minerals, alloys, 

 and glazes were conducted in the chemical laboratory as usual. In 

 addition many such identifications were made by Dr. Walcott by 

 microscopic and optical methods. Possible solvents for matter 

 which was clogging the downspouts from the Museum roof were 

 investigated and a suitable solvent found. There was carried on 

 in the laboratory an investigation of a proposed degreasing method 

 for use in the preparation of zoological specimens. The alcohol 

 used to preserve specimens of fish and reptiles had become muddy 

 and much discolored so that it was no longer suitable for use. An 

 elaborate study was made of possible methods of purifying the 

 alcohol enough to allow its continued use. The result of the investi- 

 gation showed that the only practical means was redistillation. A 

 still of six gallons' capacity was installed in the laboratory and has 

 been in constant operation since July. As the odor of the alcohol 

 which has been for years in contact with dead fish and reptiles was 

 exceedingly offensive, equipment was devised which traps this odor 

 and conducts it out of the building. The product of the still is a 

 clear, colorless liquid entirely suited for its intended use although 

 not sufficiently pure for many other purposes. Towards the close 

 of the year the laboratory, except for the still, was entirely dismantled 

 for repainting, but it is expected that it will again be in use by the 

 beginning of 1935. 



Recording a collection of culture and Oriental pearls, received 

 from Japan, in such a way that the individual pearls could be surely 

 identified if they should become separated from their labels, presented 



