626 SEC. 13. CHEMISTRY. 



precision of the readings of the instrument and to be able in various cases to 

 advance or draw back the eye-glass in the same optical axis, it rests upon a 

 glass plate mounted in a narrow-brimmed basin provided with wedging 

 screws. The regulator is formed of a glass cylinder, from whose lower 

 extremity issues a tube of small diameter which is bent upwards and rises bj* 

 the side of the cylinder, is bent at the top, descends paralled to itself, bends 

 once more, and finally ends in a glass reservoir, open at the top. 



This tube is fixed to a strip of plate glass on which is engraved an 

 arbitrary scale to serve as a datum for the air-bubble in the tube. The 

 apparatus is clamped to the brass frame at the top of the water vessel, in 

 which it hangs vertically. By its means all calculations of the corrections 

 for temperature, barometric pressure, and the tension of the aqueous vapour, 

 are avoided. 



The detonator is a mercurial eudiometer constructed like those usually 

 employed in chemistry. 



The transfuser or gas pipette is made of two glass bulbs connected 

 together by a bent tube ; one of these bulbs is surmounted by a tube which is 

 bent at an angle of about 35. It is by this tube that the aspiration or com- 

 pression is effected by means of the mouth. The other " bulb " is surmounted 

 by a capillary tube, which rises vertically, is bent horizontally, then descends 

 vertically, is bent once more, and rises again parallel to the descending tube. 

 Its extremity is. drawn out to a point. It is with this branch that the gases 

 are exhausted from or forced into the tube in which the measurements are 

 taken in the water -vessel. The whole instrument is mounted on a wooden 

 stand. The cistern for the manipulation is like that on which is placed the 

 water-vessel, but it differs inasmuch as the rim of the surface is lower. 



For complete details of experiments see " Les Annales de Physique et de 

 Chimie," vol. XX VII L, third series, 1850. 



24560. Doyere's Pipette for Gas Analysis Apparatus. 



Golaz, 24 Rue des Fosses, St. Jacques, Paris. 



245 6t. Automatic Eudiometer with alarum. 



D. Monnier, Geneva. 



2456b. Two BischoPs Evaporating Apparatus to use for 



Frankland's apparatus. One graduated nitric acid tube. Enamel 

 back. E. Cctti $ Co. 



2455a. Frankland's Water Analysis Apparatus. 



E. Cetti $ Co. 



2456b. UffcLeod's modification of Frankland's Apparatus 

 for the Analysis of Gases. E. Cetti $ Co. 



24561. Ure's Eudiometer. E. Cetti $ Co. 

 2456k. Mitscherlich's Eudiometer. E. Cetti $ Co. 



2534. Apparatus for boiling off the air from sea- water. 



Prof. Oscar Jacobsen, Rostock. 



2573. Bunsen's Cathetometer. Julius Schober, Berlin. 



