926 



SCIENCE. 



[N. S. Vol. XX. No. 522. 



led to tlie devising of a cabinet and means of 

 storing slides which has proved, in actual ex- 

 perience of a year, to be thoroughly satisfac- 

 tory in every particular. To enable the slide 

 to be stored as one v^ould an index card a 

 special envelope or jacket for the slide was 

 devised. It is made of strong manilla paper 

 and but little larger than the standard slide 

 size (1x3 in.). This jacket is given the di- 

 mensions of 3J X 1^ in., and was rhanuf ac- 

 tured in quantity at a cost of about two dol- 

 lars a thousand. The jacket affords an oppor- 

 tunity for sufficient labeling, and enables the 

 slide to be classified in a specially constructed 

 cabinet exactly as one would an index card. 

 The cabinet follows the general plan of the 

 library index case, is of five drawers of three 

 partitions each, and will hold upwards of 2,000 

 slides. The guide cards are specially cut to 

 correspond with the slide envelope, and have 

 on the lower edge an extended lip perforated 

 for the countersunk retaining rod which runs 

 just below the level of the slides. This holds 

 the guide cards and gives additional security 

 to the slides, which remain readily in place 

 by their own weight. Each cabinet is ar- 

 ranged with a lock which fastens all five 

 drawers and gives security to the material. 

 The drawers have the retaining device so that 

 there is no danger of their being pulled en- 

 tirely out and their contents spilled. The 

 envelopes, however, give such protection to the 

 slides that they will not break even from fall- 

 ing some distance, and, furthermore, protect 

 them entirely from dust. 



This system of storing slides allows for ad- 

 ditions to be made indefinitely, just as in the 

 case of the card catalogue, and enables the 

 most minute and accurate subdivisions and 

 classification of material, especially important 

 where so large a number of subjects are being 

 accumulated and studied as is indicated above. 

 The adoption of this system of filing slides has 

 decreased the work of consultation and hand- 

 ling material at least two thirds, and has rend- 

 ered such consultation and handling so easy 

 that the whole collection is more often con- 

 sulted and correspondingly much more service- 

 able than before. These cabinets, while spe- 

 cially made, are inexpensive, and seem to have 



solved the problem, at least so far as perman- 

 ent balsam slide nrounts are concerned. In the 

 writer's own preparation of material in his 

 special subject the slides are always thorough- 

 ly dried over an alcohol flame as soon as they 

 are prepared. In the case of mounts which 

 can not be thus dried this system will not 

 apply, for the slides can not be placed in such 

 cabinet until they have become thoroughly 

 dried. Once thoroughly dried, however, the 

 intense heat of a Washington summer does 

 not result in any softening or attachment to 

 the enclosed jacket. This system of keeping 

 slides has met with the general approval of 

 all who have seen it, and it seems, therefore, 

 desirable to give it this exploitation for the 

 benefit of those working with similar material. 



C. L. Maelatt. 

 U. S. Department of Agricultuke, 

 December 7, 1904. 



QUOTATIONS. 



CONVOCATION" WEEK AT THE UNIVERSITY OF 

 PENNSYLVANIA. 



The American Association for the Advance- 

 ment of Science held its first meeting in 

 Philadelphia in 1848. After an interval of 

 thirty-six years it met for the second time in 

 Philadelphia in 1884, when the attendance 

 was 1,261. This was the largest meeting in 

 the history of the association, but the numbers 

 were increased by 303 members of the British 

 Association, which met that year in Canada. 

 At the Boston meeting of 1880 there were 997 

 and at the Montreal meeting of 1882 there 

 were 937 members in attendance. These 

 meetings representj^^ culminating point in the 

 history of the association, and an important 

 epoch in the development of science. Until 

 1882 there were only two sections of the asso- 

 ciation, one for the exact sciences and one for 

 the natural sciences. But at about this 

 period specialization and differentiation be- 

 came imperative. The conditions were in, 

 part met by dividing the association into sec- 

 tions, but more adequately by the establish- 

 ment of special societies. The American So- 

 ciety of Naturalists was organized in 1883, 

 and has since held winter meetings, the mem- 

 bership being confined to professional students 



