340 NATURAL SCIENCE. Nov., 



interest are chiefly to be found among the Educational Exhibits in 

 the Manufactures and Liberal Arts Building. Here such institutions 

 as Harvard, Johns Hopkins, Princeton, Columbia College, and the 

 University of Pennsylvania illustrate the methods of their science- 

 teaching and of th3 original research carried on under their auspices. 

 To a scientific man this is the most interesting part of the whole 

 Exhibition ; for we are all of us students, and a few of us are teachers. 

 Still one must regret that so small a part of the Exhibition is on these 

 lines, and that foreign countries are so little represented. Japan, 

 indeed, gives evidence of her new birth in this direction as well as 

 in others ; but where are the Laboratories and Museums of our old 

 Universities ? where is the Royal College of Science ? where are 

 Bonn, Heidelberg, Freiburg, Liege, Paris, Upsala, Dorpat, and 

 Bologna ? Surely the heirs of Galileo need not shun the land of 

 Columbus. What an exhibition rises before the scientific imagination 

 at the mere mention of these few names ! But, alas ! men of science 

 are too poor even to advertise themselves, so we must make the best 

 of Chicago, and that which the American Universities have been 

 good enough to do for us. 



From these exhibits each visitor will carry away thoughts in 

 accordance with his own needs. The following are what appear in 

 my note-book. A giant microtome, used chiefly for cutting microscope 

 sections through the entire brain, exhibited by the University of 

 Pennsylvania. The object to be transected is fixed at the end of a 

 very heavy lever and is allowed to sink down upon the edge of a broad 

 knife, the blade of which is parallel to the side of the lever. The 

 section as it comes oflf is caught on a sloping sheet of paper. The 

 Biological Laboratory of this University makes a regular practice of 

 selling photographs of preparations, specimens, and drawings ; and a 

 catalogue of such, which might prove useful to lecturers, may be 

 obtained from the Secretary. Lecturers will also be interested in 

 some models of brains exhibited by the Physiological Department of 

 the Loomis Laboratory of the University of New York City. These 

 models are first of all constructed in clay ; the clay is then covered 

 over with strips of newspaper soaked in glue, which form a shell 

 about a quarter of an inch thick. When the structure is quite dry, 

 the clay is removed, and the hollow paper model remaining is 

 appropriately coloured in oils. Such models may be made any size, 

 are very light, and will stand rough usage. In the Harvard Zoological 

 Department, W. McM. Woodworth exhibits some enlarged wax 

 models of microscopic objects which are constructed from thin 

 sections by an ingenious method. A camera drawing is made of each 

 section in the series on some thin paper. The drawing is then attached 

 to a sheet of wax which bears the same proportion to the thickness of 

 the original section as the drawing does to its area. Each sheet of 

 wax is trimmed to the outline of the drawing, and the successive sheets 

 are then stuck together. The details of manipulation, which cannot 

 be described here, are fully illustrated by specimens and apparatus. 



