r* 



BAIRD &.TATLOCK (LONDON) LTD. 



858 



Thoma's Haemacytometer, by Leitz, consists of an object glass with carefully constructed 



cell, a ground absolutely plane cover-glass and two pipettes for mixing the blood and 

 saline solution used in the examinations. One of these pipettes, for estimating the number 

 of red corpuscles, is so graduated as to permit dilution of the blood 100 or 200 times as 

 required ; the other, for counting the white corpuscles (leucocytes), is graduated for 

 dilution of the blood 10 or 20 times .. .. .. .. .. each 1 50 



A full description is supplied with each instrument. 

 >5' Mixing pipette for white corpuscles, diluting I in 10 .. .. .. 040 



56 T ,, red ,, ,, i in 100 . . 040 



>7 T Slide with cover-glass .. .. .. .. .. .. .. 13 



The volume contents of the pipettes are most carefully determined, and the depth of the cell 

 established by accurate micrometric measurement, thus permitting very exact observations by 

 cans of this instrument. 

 >8 T Apparatus for the Clinical Determination of the Alkalinity of the Blood (after C. S. 



Engel a modification of the method of Lowy and Zuntz). The following parts compose 



the apparatus : 



1. A capillary pipette so graduated as to permit the dilution of 0.05 cubic centimetre blood 

 from the finger up to 5 cubic centimetres with distilled water. 



2. A beaker for the reception of the diluted blood. 



3. A burette of 10 cubic centimetres capacity, mounted on a stand, each cubic centimetre 

 having 20 divisions on the scale. 



Full directions for the use of this apparatus accompany each outfit. Price, in box .. each 1 00 



. 



59 T Ehrlich's Eyepiece, provided with a diaphragm having a square opening, the size of which 

 is regulated by a small lever. This eyepiece is designed to facilitate the estimation < 

 relative numbers of red and white blood corpuscles in dry preparations 



Full directions accompany each instrument. 



each 1 10 



iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 



177 



