798 SEC. 18. BIOLOGY. 



3755. Lowne's Patent Portable Spirometer. 



R. M. Lownc. 



The measurement of the vital capacity is obtained by measuring the velo- 

 city of the expired current during the time of expiration, and the instrument is 

 arranged so as to reduce the velocity of the current to cubic measure. The 

 indications of the instrument are shown by means of hands revolving on a 

 dial which denote the number of cubic inches expired. 



3755a. Improved Portable Spireometer. E. Cetti S? Co. 



3755b. Hsemotachometer of Vierordt (1857). 



Professor Vierordt, Tubingen. 

 The stand to be used with the instrument is omitted. 



3756. Pump for Transfusion of the Blood. Invented by 

 Dr. Valentin. 



Geneva Association for Constructing Scientific Instru- 

 ments. 



This instrument is noteworthy by reason of its being composed of a glass 

 cylinder, thus making visible the presence of air in the pump. The piston also 

 is made of a single piece of glass, which ensures the greatest possible 

 cleanliness. 



3756a. Blood Transfusor. Collin and Co., Paris. 



3756b. Spiroscope. Collin and Co., Paris. 



3756c. Aspirator of Liquids. Collin and Co., Paris. 



3756d. Apparatus for delicate Injections. 



Collin and Co., Paris. 



3756e. New Spiral Setter. Collin and Co., Paris. 



3756f. Hematimeter, apparatus intended to determine the 

 number of globules in the blood, by Dr. Hagen and A. Nachet. 



A. Nachet, Paris. 



3757. Sphygmograph of Vierordt (1853). 



Professor Vierordt, Tubingen. 



The pad for fixing to the arm with the weights for equilibrating the instru- 

 ment are omitted. 



3758. Fhoto-sphygmograph, with magnesium lamp, con- 

 denser, and plaster cast. Dr. S. Th. Stein, Frankfort. 



This apparatus is used for photographing the human pulse. See Vogel's 

 "Photogr. Mittheilungen," September and October 1875. Specimens of the 

 photographs, a normal and fever pulse tracing, accompany the instrument. 



3759. Sphygmodynamometer, an apparatus for estimating 

 the blood pressure in the radial artery of man. 



Dr. C. Friedldnder, Strassburg. 



The apparatus is made for determining the variations of the blood pressure 

 in the radial artery in man ; e.g., the diurnal variations, the changes which 

 the blood pressure suffers under the influence of poisons and various physio- 



