. Journal of applied microscopy and laboratory methods. arm so that it may, at thewill of the operator, be instantly thrown in orout of the optical axis by a lever; a suitablestop bpng provided to bring it to a centralpositi .ii. The lower lens is mounted at the properdistance below the upper surface of the appa-ratus so that when the upper lens is movedout of optical axis, the lower lens focuses uponthe slide, thus avoiding the necessity of re-focusing the condenser system when changingfrom the double to single combination. The Nicol prism is mounted inrevolving sleeve with graduated collar a
. Journal of applied microscopy and laboratory methods. arm so that it may, at thewill of the operator, be instantly thrown in orout of the optical axis by a lever; a suitablestop bpng provided to bring it to a centralpositi .ii. The lower lens is mounted at the properdistance below the upper surface of the appa-ratus so that when the upper lens is movedout of optical axis, the lower lens focuses uponthe slide, thus avoiding the necessity of re-focusing the condenser system when changingfrom the double to single combination. The Nicol prism is mounted inrevolving sleeve with graduated collar and a stop to indicate zero or the positionof Nicol prisms when crossed. The advantages of this arrangement over others for accomplishing the sameresults are, briefly, as follows: First—It is not necessary to increase the size or thickness of the microscopestage. Second—The attachment is always in focus whether one or both lenses are —Compactness and freedom from liability of disturbance while operat-ing stage or slide. W. L. 1156 Journal of Applied Microscopy 7 r\ M A Plan for a Ureometer. The plan for a ureometer (or modification of Doremus apparatus) here pre-sented would, it is believed, offer some advantages as to accuracy and facility ofmanipulation over other methods of estimating urea. C is a tube of about ^5 cubic centimeters capacity, closed at the upper end,and accurately graduated from the upper end downward for IG c. c, to tenths ofa cubic centimeter. The graduation also gives urea percentages to tenths per cent., at 20°C, and barometric pressure of 760 mm. ofmercury. At the bottom of tube r is a curved neckcommunicating with a bulb />, which opens into a tube(7; this has a funnel top, and is of the same length astube c. The capacity of bulb ^ is about 30 c. c, whichquantity is indicated by a mark on tube a. Tube c communicates near its lower end with asmall tube ^/, joined at such an angle and position thatgas generated in ^/ will ri
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
