18 RICHARD SEGEDI AND WILLIAM E. KELLEY 



We have modified the Backhaus for- synergistic toxicity, we have reduced these to the 



mula for artificial sea water into a 4-step ''^"i^""!' ^^"^^ ^" "''^'""^^ '^^ ^^*^^^- 



, 1 1 /r. d. ue have eliminated the boric acid used by 



preparation as shown below (for prepar- j^^ Backhaus to inhibit plant growth in amounts 



mg 100 gallons with specific gravity of up to six ten-thousandth parts. 



^ ' PART T ^^^^ have not found it necessary to use 



chemically pure (CP) substances throuffh- 



NaCl 10.43 kg. Technical ^, j- i -n t! i i 



^ , out as did Dr. Backhaus. 

 grade. 



MgClz.eHjO 2.04 kg. Do. ^''^^'^ I of the formula consists of its 



MgSOi.THaO 2. 62 kg. Do. gross dry components, and these may be 



KCl 277. 8 g. Do. weighed and placed in a mixing tank. A 



f!^^^V^?r.; ^^'^ ^" . , ^''■, hard stream of water directed into them 



SrOl2.6H20 7.5 g. Analytical -n t i j^i ^  -, mi 



reagent ^'^^ dissolve these chemicals. The con- 



Mn(S04)2 1. 5 g. Do. tainer may then be filled almost to the level 



Na2HP04. 7H2O-- 1.25 g. Do. of the desired specific gravity. 



LiCl .375 g. Do. Part II, which consists of the calcium 



Na2Mo04. 2H2O-. . 375 g. Do. ii -i ' r i j • i ^ ^ j 



* chloride, is dissolved m hot water and 



PART II added to the mix. Additional water may 



^ ^, coo -x. 1, • , then be added to bring the mix to the cor- 



CaGl2 522 g. Technical . . . *= . 



grade. ^'^^t specific gravity. Calcium chloride is 



T^A^^ T?.^.,T,x,^ a^^^^ a^.xr ^„ mixed separately because, at the high con- 



iRACE HiLEMENT OTOCK SOLUTIONS . 



. , , centrations of the gross comiDonents, it will 



Add 80 cc. each of solutions III and IV. j -^i ^i • 1 r. , / c 



react with the magnesium sulfate to lorm 



PART III magnesium chloride and calcium sulfate, 



Calcium Gluco- the latter of which will precipitate. 



nate 6.25 g. U.S.P. Parts III and IV, which are stock solu- 



KI .9 g. Analytical tlons of trace elements, may now be added 



reagent. ^q ^j^^ j^jx. Liquid Stock solutions of 



n or\ ^Tj W A o ^ T->^' these are desirable because (1) the assem- 



CUSO4. 5H2O 4.3 g. Do. , n j: XI X • T . , 



bly 01 the parts is made more convenient, 



Dissolve in 2 hters of distilled water. /-.n « ,, , . ,. 



{2} some or the compounds providing 



PART IV trace elements must be dissolved by heat 



Al2(S04)3 4.5 g. Analytical (calcium gluconate, cobalt sulfate, and 



reagent. aluminum sulfate), and (3) better quanti- 



C0SO4 .5 g. Feed grade. tative accuracy may be achieved by weigh- 



RbCl L5 g. Analytical ing out relatively large amounts for the 



reagent. '^ ^ , . ~r . ^^ • 



ZnS04. 7H20_. -_ .96 g. Do. stock solutions. If chlorinated tap water 



Dissolve in 2 liters of distilled water. ^^^^ been used, the solution must be aerated 



for a day or two before adding parts III 



We have also altered a few of the pro- and IV, or the residual chlorine will dis- 



portions 01 its constituents : place the ionic bromine and iodine since 



1. The Backhaus formula includes slightly the latter occupy a lower position in the 



more than a millionth part of iron, which we electromotive series. 



have omitted because our Great Lakes tap water nr i 1 1 1 j.  j. • 



, ^ We have been al)le to maintain marine 



i.s relatively rich in this element. . . , ,. . • 1 • • r> • i 



2. The Backhaus formula calls for about one "^vertebrates indefinitely m this artificial 

 five-thousandth part of zinc sulfate and one ^ea water— something we have not been 

 fifty-thousandth part of copper sulfate. Fearing able to do with any other type. 



