water. Each bottle should be labeled and 

 dated after it has been filled. 



13-5 Electric Hotplate. — An electric labora- 

 tory hotplate of the Hotcone type, which is de- 

 signed for use with beakers and flasks, is used 

 for boiling starch solutions (used in oxygen de- 

 terminations, preparing other reagents) and 

 sterilizing small equipment. 



13-6 Magnetic Stirring Apparatus. — Sea 

 water samples analyzed by titrations must be 

 stirred in a very regular and precise manner 

 during the running of a titration. To best ac- 

 complish this a magnetic stirring apparatus is 

 used. This is essentially a horizontal magnet 

 attached to the vertical shaft of a small electric 

 motor. The speed of the motor is controlled by 

 a rheostat. A beaker of sample is placed over 

 this magnet and another magnet, which is 

 plastic covered, is placed in the beaker. The 

 latter is revolved in the beaker at the same speed 

 as the motorized magnet beneath, thus stirring 

 the sample at a constant and controlled speed. 

 Such magnetic stirrers are necessary for salinity 

 and oxygen determinations. The use of plastic- 

 covered magnets is recommended over that of 

 glass covered ones due to the higher breakage 

 rate of the latter. 



13-7 Beam Balance. — A good quality triple 

 beam balance, accurate to the nearest 0.1 gram, 

 is used for weighing various chemicals required 

 to make many of the solutions. Naturally, a 

 beam balance cannot be used while the ship 

 is at sea, so all weighing must be done before a 

 cruise or while the ship is in port. Wherever 

 possible, weighing of chemicals that requires 

 accuracy should be done ashore and the beam 

 balance is used only for weighing those chemicals 

 that do not require a high degree of accuracy. 

 Certain chemicals must be dried carefully and 

 weighed on an analytical or gram-atic balance 

 in a shore laboratory and then sealed in vials 

 or jars for use at sea. 



13-8 Miscellaneous Laboratory Equip- 

 ment. — In addition to the major pieces of equip- 

 ment discussed above, the shipboard laboratory 

 is furnished with a large variety of apparatus 

 used for many types of analyses and other work 

 at sea. The following list of equipment will 

 serve as a guide for equipping a shipboard 

 laboratory although it must be kept in mind 

 that requirements vary considerably for dif- 

 ferent ships and surveys. ].,ists of chemicals 

 and equipment required for each type of analysis 

 are listed with the instructions for that analysis. 

 Aprons, laboratory. 



Beaker, Griffin low form, Pvrex, with pour- 

 out capacity: 50, 100, "250, 400, 600, 

 800, 1,000, and 2,000 ml. 



116 



Bottle, sea water sample, with consecu- 

 tively numbered porcelain stoppers and 



rubber gaskets. 

 Bottle, wash, Pyrex, 500 ml. 

 Bottle stopper extractor. 

 Brush, beaker, cylinder, or funnel, with 



wooden handle. 

 Brush, burette, fan tip. 

 Brush, flexible pipe cleaner. 

 Burner, liquid petroleum, Bernzomatic 



type, with complete set of tips. 

 Clamp, beaker. 

 Clamp, test tube. 

 Clamp, burette, symmetrical screw-clamp 



type, rubber-covered jaws. 

 Clamp, table, for supporting 19 mm. 



threaded rod. 

 Clamp, tubing, Hoffman improved form, 



}^inch. 

 Clamp, tubing, Mohrs, pinchcock, im- 

 proved form. 

 Clamp, utility, castaloy, rubber sleeves, 



large size. 

 Clamp, holder, castaloy. 

 Cork borer set, brass with handles. 

 Corks, assorted sizes 3 to 16 xxxx quality, 



regular length. 

 Cotton, absorbent, in 1-pound packages. 

 Cylinder, single graduated, Pyrex capacity: 



"lO, 25, 100, and 500 ml. 

 Dish evaporating, Coors, porcelain sizeNos. 



3 and 4. 

 File, triangular, 4-inch, for glass cutting. 

 Filter paper, qualitative circles, smooth 



white, 18.5 cm. diameter. 

 Filter paper, qualitative circles, heavy 



white creped, 40 cm. diameter. 

 Filter pump (aspirator), brass, %-inch in- 

 side pipe size thread, with threaded filter 



pump coupling. 

 Flask, boiling, flat bottom, vial mouth, 



Pyrex, capacity: 250, 500 ml., 1 liter. 

 Flask, Erlenmeyer, narrow mouth, Pvrex, 



capacity: 125, 250, 500 ml. 

 Flask, volumetric, contain and deliver, T. 



S. stopper EXAX, blue line, 500, 1,000, 



and 2,000 ml. 

 Flush plate bases, threaded for 19 mm. 



support rods. 

 Forceps, bottle, nickel plated. 

 Funnel, Bunsen, 125 mm. Pyrex, short 



stem. 

 Funnel, ribbed, heavy molded. 

 Gloves, rubber. 



Lamp, titration, fluorescent daylight. 

 Lubricant, stopcock, 1-ounce tubes. 

 Mortar, porcelain, Coors, with pour-out 



lip and porcelain pestle, 80mm. diameter. 



H. O. 607 



