The Microscope. 41 



surface of Lemna polyrrhiza, and among the leaflets of Myriophyl- 

 lum. None have been found sexually mature, reproduction being 

 ordinarily by transverse fission. 



EXPLANATION OF THE PLATE. 



Fig. 1. uSHolosoma distichum, sp. nov. 



Fig. 2. uS£olosoma distichum, termination of segmental organ; 

 diagram. 



Fig. 3. ^olosoma distichum, blood vessels of the head; dia- 

 gram. 



Fig. 4. Pristina flavifrons, posterior extremity. 



Fig. 5. Pristina flavifrons, anterior extremity; ventral view. 



Fig. 6. Pristina flavifrons, anterior extremity; profile. 



Fig. 7. Pristina flavifrons, podal stylet. 



Trenton, New Jersey. 



THE SPECTROSCOPE AND ITS APPLICATION TO MEDI- 

 CAL PRACTICE.* 



DR. S. WATERMAN. 



I HE telescope, the microscope, and the spectroscope are three 

 great lights to aid man in scientific investigations. The 

 telescope has conquered space, and revealed to us the beauty and 

 grandeur of the starry heavens; the microscope has made its 

 acquainted with a new world, with a miniature creation, invisible to 

 our unaided vision, a world so full of beauties and enchanting 

 sights, and of the greatest usefulness to unravel the structure of 

 organic and inorganic matter. The spectroscope, with its analytical 

 prisms, has revealed to us the composition of celestial worlds, as well 

 as the chemistry of terrestial matter. We may leave the astronomer 

 to sweep the infinite realm of space for new wonders and new dis- 

 coveries; enthusiastic votaries penetrate the infinitesimal world with 

 their powerful microscopes, in which department it reigns supreme. 

 To describe the spectroscope, its wonderful analytical powers, its 

 conquest in celestial and terrestial chemistry, this, it shall be my 

 task to lay before your kind consideration ; in rendering an account 

 of the spectroscope, and its applicability to medicine, we enter a 

 field of inquiry, whose limits have not yet been reached, nor its 

 depth and breadth fully explored. 



It is not claimed that the spectral, or prismatic test is destined 

 to supersede other modes of procedures hitherto employed by the 



'Copyright, 188S. 



