described above the heavy a~iplicatioiisof inorganic fert.ilizers, while furnistiing an adequate supply of the inajor nutrients, could not meet the deficioiicy of iiinnganeso iii tlie soil. However, bhe manure apparently carried sufficient manganese to supply the dcmiinds of the plaiit,. Hence future fertilizer practice must take indo coiwidimition t,he role of manganese and other elenrents which may be prorcd indispensable to pltirit growtli and fnnction;
provision must be niade for determining deficiencies where they occur and meeting thein through appropriate suppleinents to the fertilizers applied. At t.be same time it should be emphasized t,liat the amounts of the constituents required are exceedingly sniall and t,irat precautions must bc excreised to prevent risk of toxic effects from excessive applications or from applicatioiis to soils and addition to fertilizers already supplying amounts sufficient, for plant. requirements.
Interchangeable Unit Laboratory Furniture' O M E features of t.lic l:iborrit,ory fiiriiitnre ilesigmd by the staff of tlic Ikpnrtmaiit of (',liwuii~:allhgiiiceritig of t,lic 1:nirersity of Michigan 11:iw prorod of siiffioioot valuc duriiig tlic tlircc years of opcratiim to rvarrttnt tlieir descriptioii. Prior exjx:ri(:nrt! li:irl tniiglrt, that the type of funiitiire iriost ncrrled iii :L given Idiomtory would vary froni ye:w to yenr, ii1111 t,li:it l ~ w v yfixed ~ fnniitnre was undesir:iblc. It w a i lit r tu kccp the cost of iiew furnit,uro lo\\-, iiiiii it irnblc to taka ndv3ntngc of hhe ecoiiornici rcsiilting FS prodi~r~tim or st;iialardizetl nnitrj. Tlic icatures described liere are not :LIIn w e l , hiit it is iiclicved that the resultatit furniture is iliffmmt from that iii any otlrer laboratory. A11 uriits-~ial,~irat~iry desks, sinks, lroods, apparatus cases-were iiiade of sta unit of its kind could lx?placed next to a ~ i o t l sor r siilistitutcil for onot,licr.
S
Desks
The niost iiistiiictive features arc seen i n Figurw 1 and 2, which show two riews of the end units of ii r1oul)le row of laboratory desks. Icignre 1 shows norn~;d nppcarnnce of the assembled units and Fieiire 2 m s tlic siiiiii: eiiiiiij-
dnits. The sinks are carried oii indepeiident pipe frames and the iead waste pilies discharge vcrticniiy into it leadliiied wooden trongh wlrich lias B iliwliarge at. one end through :L lead pipe iuto a n iron soil pipe susycndcd from the ceiling of the rou~rihelow. Tlie pip nd sinks were instdied while there was entire freedom for t,lie workmeii to nse tlieir tank on bot,li d e s of the rack. \Vhen the pipe work was completed the beneli units were pushcd into plaoe and the desk was conlplete. If are needed tire piping system becomes completely .ibk by prilling away the bench units. li:aoh bench 5 feet long, 21 inches wide, and 40 inahes high. Ench pipe rack is also 5 feet long, 64 inches high, and 9 inches vc.iilc. An exception is to he noted in t.lie pipe racks w-liicli carry the flues for down-draft hoods where tlie width of the r x k is increased to 12 inr:hes. T h e constroclion for single desks to stand against the wall is similar. The desk units theniselves are identical, but tlie sinks for the single units are shorter. A corner of n single nnit with its sink is shown i n Figure 3, wliich also shows the lead pipe from the sink and the iron waste pipe from the iiood uniting i n a cast-iron soil pipe tee. Castused for all waste lines after leaving tlie
Fieure I - LahoraIory ~ Ilcsks. Complete Assembly
Pleurs 2 --Laborrrcory Desks, Bench Unirs Removed
nient wit,lr tire bench units piilled i r i i t US tlie way tu perniit access to the piping. All pipes are carried on a wooden pipe rack which stands between the two tables. The pipe rack shown in Figure 2 carries a soctiini flue for downdraft desk hoods, pipes for steam, waterr gas, and compressed air, a lead-lined trough for waste water, and elect,rical con-
tables, the favorable experience of fiftceri years i n the Chemistry Building having shown that acid-proof iron was unnecessary for our purposes. The value of this design has been proved not only when repairs or alterations have had to be made to the piping or wiring system, but also vhen it has been desirable to convert a laboratory to different uses. Single units have been
3
Received Novemher 8, 1926.
Mtirch: 1921'7
I.vI>~~'*Y7~losXrperiment Stat,ioii, iiicludeil somc esperinicnt~swith n~aiigti- iessiiig i~ ricgligible inanganex! wiitent :is C i l i l l p 2 i T ~ d wit11 nese sulfate a i d ferrous sulfntc h i i g iwitli tlie geiiernl fcrti- tlic gimcrttl ruii of American soilk, it rievertholeis furiiisties lizer study. 'Tlie rcsult,s of t,liis test in the field on the coli- :I striking illustraLioii of :I, h i d id problcrri that may mise ditioii arid yield of tho crop BTF of interest and sigiiifiennce more Ereqiient,ly in tlie intiire: witli tlic more inteiisive iiew iigricultural as bearing aut the laboratory results in a practiaai way. wliii~iitiuiiof old arid the developiiient iircas, t,ogctlinr witll the iiiiliantion of iirorlcrn pure Ewtiliacr Tlic inangnnese sulfikte3or ferriiiis siiliate, \was distrihiited orer areas one f ( J 0 t Srom tlie plniits in two applieations, materinls of clicniicttl rnnniifnctiirc. In tiie first place, the first a t the time of setting iiiid tlie Fecond 2 wucks later. p r e s a i l i ng conditions Tile total amount was cquirtihit, to :i 1iroadc:rst :ippli&ioii of about 150 pounds per acre. l'hc inorgnnio fertilizer, itre stimulating the exiiitogetlier :WOO pouiids t:r1 m:lllgaur!se.
0
crate, li"1d 50 pouiids.
Tlie addition of iriarigariesc with 2000 ~ I J U I I ~ofS mililtire per acre gave incrcnses iii yields omr those from 1500 p i l n d s of maiiure without imuiganese, amounting to 32 atid 24 per cent, respectivcly, for two separate fields; tlic iricresses in yields, orer those from 3000 pounds oE manure witliout rnaiigniiesc, were 9 a i i d 18 per cent, respecbirely. Wlierc 1000 pounds of peat per acre were substituted for manure tlie yields, on :iddit,ioii of niaiiganesc, exceeded those fromi blie same ainouni of peat. witliout mnriganese by 48 arid 84 per cent, respectively. Purtiiermore, tlicy surpassed tilose from 1500 poiinda of maiiure wit,liout mangarmc by 8 and l!) pcr cent; and, as coinparcd wiili tliosc fmtil :3000 p(J1Ilids or iiiail~rchut no mang:iocsc, d i i k there w s :I decrease of 12 per cent in the m e ease, there was tin increase of 1:1 per ceiit iii the other. At, t l i e same time superior growtli of plants nod color of foliage TTM noted in all cases where manganese \*-as present,. Ferro113 sulfate applirnlioiis rcsulted in yichla slightly lowcr tliaii tlrose from the corresponding check plots. Tlie results of t,iie laborntory experimeiits are t,lius esseii-
In the second pltice, iiioilerii trend in regard to fertilizer iiiriterials may give rise to problems of n similar nature. Tlic older fert,ilioers, consisting of, or derived from, plant mid animal by-products or offal, and even tlre inorganic Ecrt,ilizor salts originating in natural deposits and comtairiing greater or less amounts o i aeeonipanying impurit,ies, nrr hoing supplanted, and will in tlie future be supplanted to :i greater cstcnt,, by m:inufaetiired products of i i iiigli degrw of purity, especislly t,lic :iir-dcriveil iiit.rogeii products. 'lllic applic:&m uf tlrose ciiemical iertilizer substances i o t,lic gaieral ruii of soils containing sufficient reserves of tiit. r iriorgniiic ci~iist.itiieiitsis not likely to iilrolve any pmhlcm of deficiency frorli that source. On the other h a d . under conditions .shere these constiiuerits may he deficient or unsvailahle, or mny in time become so, the results of such defieieney will probably be encountered; with the rruder fertilizer innterinJ8 sufficient ainounts of the necessary clernciits miglit be supplied as impurities. In the prolileiii
