774 SEC. 18. BIOLOGY. 



putrefactive or other fluid without allowing it to evaporate. The glass cup 

 to the right is to be filled with water. The capillarity of the linen carries 

 over a constant supply of moisture ; part of this linen is included in the 

 central cylinder into which the object glass projects, and the water thus 

 constantly carried into this air-tight chamber causes the air therein to become 

 so saturated that evaporation from the fluid under examination cannot take 

 place. The highest powers may be used, because the india-rubber diaphragm 

 yields instantly to the screw of the " fine adjustment" 



3598. Microscopic mounting materials and dissecting instru- 

 ments, consisting of: 



Wood-cutting instrument and chisel, instrument for cutting 

 circles of thin glass, glazier's diamond, writing diamond, cell- 

 making instrument, brass table and lamp, Page's forceps, case of 

 dissecting instruments (containing four knives, two hooks, two 

 points, three pairs of scissors, three pairs of forceps, and needle- 

 holder), Valentin's knife, 1 oz. thin glass, 9 doz. slips (3 in. by 1 in.), 

 3 doz. wooden slips, 3 doz. cells, 200 labels, 5 capped bottles (con- 

 taining Canada balsam, asphalte, gold-size, glycerine, and marine 

 glue), bottle of Deane's medium, three stoppered bottles for con- 

 taining chloroform, nitric acid, and liquor potassse. R. fy J. Beck. 



3603. New Sub-stage Condenser, comprising achromatic 

 condenser of high angle of aperture. James Swift. 



The above is an effective spot lens, from 3 inch objective to inch ; it has 

 centering adjustments, contracting diaphragm, and complete polariscope, in 

 which all the colours of the rainbow can be obtained. It also forms a complete 

 substitute for every piece of apparatus used under the microscope. 



3604. low Angle Objectives. A series from 1 inch to 

 ^ inch. James Swift. 



3605. Popular Achromatic and Tinted Condenser. 



James Swift, 



This apparatus combines the achromatic condenser, light modifier, spot 

 lens, and polariscope. 



3606. Microscopic Objects, illustrating every department 

 of microscopy. 



Machine for cutting sections, with knife. 



Improved turn table. 



Hot plate and lamp. 



Spring compass, and spring clips. 



Instrument for cutting circles in thin glass. 



Glass slips and thin glass covers. 



Labels for covering and naming objects. 



Buff block for cleaning covers. 



Centering card. 



Case of dissecting instruments. 



Knives, forceps, needles, &c. 



Syringe and appliances for injecting. 



