360 The Microscope. 



that a society composed of men from the different professions and 

 from mercantile life, should be able to discuss papers and topics of 

 special and general interest. He laid great stress upon the fact that 

 the Society was formed not only for microscopical work, but for the 

 study of the microscope itself, as an instrument, and he invited the 

 members to discuss questions and read papers on the technique of 

 microscopy, as well as upon other matters of interest to the society. 

 Dr. A. K. Bond spoke of the Phenylhydrazin test for sugar in 

 the urine, as applied by Prof. Ultzmann, with special reference to 

 the character of crystals formed. He remarked that the detection of 

 sugar in the urine had for a long time been a subject of interest to 

 practicing physicians. The amount of sugar which might be present 

 in the urine of a patient might vary from a few grains to several 

 ounces a day. Sometimes a patient's attention was first arrested by 

 the crystallization of sugar in drops of urine which had fallen on his 

 or her clothing. For the detection of sugar many tests had been 

 used. There was the Polariscopic method, in which the plane of 

 polarization of a ray of light passed through a specimen of urine 

 was turned toward the right if grape-sugar was present. The 

 difficulty with this test was that it was not delicate enough and was 

 liable to errors. Next he mentioned the Fermentation test, in which 

 yeast was added to the urine in an inverted glass vessel and if sugar 

 were present fermentation took place and the resulting gas was 

 collected and tested. This method, he thought, was not very 

 delicate. Next came the group of redaction tests in which metallic 

 salts were added to the suspected urine, and, if sugar were present, 

 became reduced by the sugar to the metallic state or to salts of a 

 different color. Some of these tests were extremely sensitive and 

 very useful. In certain cases, however, a considerable amount of 

 the test-fluid might be reducsd by saccharine elements in the urine. 

 A very interesting case had come to his notice in which the reduction 

 by the urine of a gentleman who applied for life insurance was so 

 great that a number of companies refused to insure him, yet farther 

 examination by others and by himself showed that no sugar was 

 present. These facts, he thought, showed the need of some new 

 test, not belonging to any of the classes above named. Such a test 

 he here presented. It depended upon the formation of very 

 characteristic crystals containing the sugar itself. Sugar might be 

 obtained from urine in several forms of colorless crystals, as by 

 direct crystallization of the pure sugar, or by the treatment with 

 sodium chloride; but these methods were of little practical value. 



