and Laboratory Methods. 1567 



Immersion Oil in Collapsible Tubes. 



The immersion oil bottle shares with the Canada balsam bottle the distinc- 

 tion of being the stickiest and dirtiest piece of apparatus on the work table. 

 A portion of the first drop of oil to be removed is almost invariably left on the 

 mouth of the bottle and thereafter the stopper never fits tightly ; the oil runs over 

 the neck of the bottle and smears the fingers in spite of almost all precautions ; 

 in the course of time the oil thickens, turns yellow, becomes turbid as the result 

 of exposure to the light and air, and its refractive index is thus changed. A 

 container which excludes both light and air, holds the oil in such a manner as 

 to reduce the inconvenience of handling to a minimum, delivers the exact amount 

 needed each time, and is made of a material which causes no change in the 

 optical properties of the oil, is the ordinary collapsible tube which has long been 

 used for holding moist water color and oil paints. During the past few years 

 certain dealers in microscope supplies have used this form of tube as a container 

 for Canada balsam with most satisfactory results. After several annoying ex- 

 periences with bottles, the writer determined to have immersion oil put up in 

 tubes although warned that the metal of which the tubes are made might have 

 some deleterious effect upon the optical properties of the oil. During the past 

 year the tubes have been used daily in the routine bacteriological examinations 

 attending health department work and have proved to be so free from the faults 

 which characterize the bottles that on no account will the latter be again em- 

 ployed. Immersion oil which has been stored in these tubes for more than a 

 year is now being used and no signs of deterioration have been detected. The 

 oil is as clear, colorless and thin as when first made, and there is no indication of 

 change in its refractive index. Charles Wright Dodge. 



University of Rochester. 



The minute adopted by the council of Columbia University on the resigna- 

 tion of President Low gave a few very interesting facts concerning the develop- 

 ment of that institution in the twelve years during which Mr. Low has been at 

 the head of its administration. In the academic year 1889-90 the institution 

 consisted of four faculties, in charge respectively of the schools of arts, laws, 

 mines, and political science. These faculties numbered 122 officers of instruc- 

 tion, and the schools were attended by 1134 students. The library of the 

 college contained 91,000 volumes, and the wealth of the corporation was 

 estimated at $10,500,000. The faculties, schools, library, and entire equipment 

 were crowded into narrow and noisy quarters, bordering upon the tracks of the 

 New York Central Railway. 



To-day the university consists of nine faculties, in charge respectively of 

 Columbia College, Barnard College, Teachers' College, and the university schools 

 of law, medicine, applied science, pure science, philosophy, and political science. 

 The faculties now number 385 officers of instruction, and the colleges and schools 

 are now attended by 4500 students. The library of the university now contains 

 311,000 volumes, and the wealth of the corporation is now estimated at 

 $18,000,000, of which $1,500,000, in round numbers, were given by Mr. Low 

 himself. And finally, the university is now located upon a site, and possesses 

 a physical equipment, unsurpassed in beauty, comfort, and completeness, by 

 those of any institution of learning in the world. — Science, 14 : 35G. 



