Lectures on nervous diseases from the standpoint of cerebral and spinal localization, and the later methods employed in the diagnosis and treatment of these affections . lphateof copper at the bottom of the jar; this is covered with a porousdiaphragm packed with papier-mache, on which the zinc rests surroundedby water. Water is added to the battery from time to time, and alsocrystals of the sulphate of copper. This form of cell is very constant;but it is extremely difficult to repair when out of order. As a permanentbattery, such cells may last a long time with proper care ; but they oftendo n
Lectures on nervous diseases from the standpoint of cerebral and spinal localization, and the later methods employed in the diagnosis and treatment of these affections . lphateof copper at the bottom of the jar; this is covered with a porousdiaphragm packed with papier-mache, on which the zinc rests surroundedby water. Water is added to the battery from time to time, and alsocrystals of the sulphate of copper. This form of cell is very constant;but it is extremely difficult to repair when out of order. As a permanentbattery, such cells may last a long time with proper care ; but they oftendo not, as the cells may become impaired from a multitude of causes(poor construction, improper iise, etc.). HilVs Gravity Cell.—This is another modification of the Daniell is used in medicine by many neurologists. A copper plate rests on 40 626 LECTURES ON NERVOUS DISEASES. tlie bottom of the ghiss j:ir, covered witli a satunited solution of sulpluiteof copper. The zinc element is u disk perforated bv a large centralopening, through which crystals of sulphate of copper may be droppedwhen the battery is inactive. A solution of sulphate of zinc floats, with-. yiG. 147.—Hills Gravity Cell.—This cell is employed very extensively in telegraphy, and isrecommended by some authors for permanent medical batteries. When the jars are wellparaffined at the top, the cells do not salt badly. They require but little care when prop-erly set up. Personally, 1 prefer a modification of this cell (in which the zinc is placedwithin a suspended porous cup) to the one shown in the cut. It requires less care, and is notaftected by agitation. It also has a higher internal resistance. out an intervening diaphragm, on top of the copper solution, andimmerses the zinc disk. This battery must not be agitated, as the twosolutions would then become mixed. E. M. F. = Grovels Cell (1839).—This consists of amalgamated zinc immersedin dilute sulphuric acid Avithin a porous pot. Outside of this
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Keywords: ., bookcentury1800, bookdecade1880, bookidlecturesonne, bookyear1888
