VI, CIRCULATION AND RESPIRATION. 945 



To give the clockwork (made by Siegfr. Marcus, of Vienna) a uniform 

 movement, Professor Strieker has constructed a regulator the principle of 

 which is that with increasing velocity in the rotation of a balance wheel, two 

 rods are thrust from the plane of the wheel, which act against a brush and 

 so diminish the velocity. As the position of the brush can be regulated, the 

 checking of the velocity can be commenced at any time within certain limits. 



The clockwork can be made to work the bellows from 12 to 160 times per 

 minute. 



3755. Lowne's Patent Portable Spiroxneter. 



R. M. Lowne. 



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 Spirometer. E. Cetti $ Co. 



3755b. Hsemotachometer of Vierordt (1857). 



Prof. 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 the Construction of Scientific In 

 strnments. 



This instrument is provided with a glass cylinder, thus rendering 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. Col/fin $ Co., Paris. 



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



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



3756d. Apparatus for delicate Injections. 



Collin $ Co., Paris. 



3756f. Hematimeter, apparatus intended to determine the 

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



A. Nachet, Paris. 



3757. Sphygmograph of Vierordt (1853). 



Prof. ^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 on the Maine. 



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. 



40075. 3 O 



