US2238861A - Electrodeposition of metals - Google Patents

Description

Patented Apr. 15, 1941 2,238,8til

ELECTRODEPOSITION F METALS Rudolf Lind, Euclid, William J. Harshaw, Shaker Heights, and Kenneth E. Long, South Euclid, Ohio, minors to The Harshaw Chemical Company, Elyria, Ohio, a corporation of Ohio No Drawing. Application July Serial No. 217,774

3 Claims.

This invention relates as indicated to electrodeposition of metals and more specifically, to a process of and materials for use in the process of electrodepositing nickel characterized in that the resulting nickel plate, as deposited, is both bright and ductile. More particularly, the present invention has to do with new addition agents for producing the above-named desirabl char-J acteristics in the nickel plate and which may be used with aqueous acid nickel baths of usual composition operating under usual conditions.

In order to properly evaluate the present invention, it" is necessary to define brightness and ductility or brittleness, terms heretofore used to describe all degrees of brightness or brittleness.

BRIGH'INESS It is obvious that an extremely thin deposit of nickel over a highly buffed surface will appear bright. Bright plates of this type have been made for years and are well recognized in the art. Their limitations are that if the plated article is exposed to the atmosphere or to wear, the plat soon disappears or wears oil. A plate thinenough so that it will retain substantially the full brightness of the polished base metal is impractical for use even as a base for the electrodeposition thereover of a protective coating of other metals such as chromium. If a heavier deposit is plated out, the brightness of the highly.

buffed surface diminishes and a gray or white dull deposit is obtained.

A nickel plate which isthick enough to be practical for use and which is bright without bufling is not only desirable per se, but it is particularly advantageous where it is destined for use as the base for an electrolytically deposited chromium plate; since, if the nickel plate does not require to be polished and buffed, a relatively thin plate gives the same protection as the neces-- sarily heavier gray plate, some of which must be taken oil in the polishing to'secure the desired brightness. Furthermore, a very considerable saving in time and cost on the production of plate articles becomes possible, whether with nickel plate per se or with additional chromium finish.

The addition agents of the present invention jointly produce a plate that not only maintains the brightness of the most highly polished base metal, irrespective of the thickness of the plate, within practical limits, but also increases in brightness with increase in thickness of the plate on an unpolished surface. The brightness produced by such addition agents may be characterized as brightness increasing with thickness of plate on an unpolished surface."

The question of ductility is one of vital concern to the plater. In general, all bright plates are harder and, therefore, more brittle than ordinary dull nickel. when enough or many of the previously employed addition agents was added to a bath to produce a bright plate, the plate was often too brittle for commercial us and yet if less addition agent was used, the plate would not be fully bright.

A test for ductility may be made by plating on a non-adherent surface and stripl nl of! the foil and bending it double on itself. A plate .001" thick which will pass this test without breaking is herein termed "highly ductile." A plate .0005" thick or thicker which will pass this test is herein termed ductile and is satisfactory for many uses.- A plate .0002" thick which will not pass this test without breaking is herein termed "brittle or of poor ductility.

The addition agents of the present invention not only produce plate with the highest order of brightness, but also "ductile" or highly ductile" plate as defined by the above scale. This is desirable and essential to the practial use of bright nickel plating.

The principal object of the present invention, therefore, broadly stated, is to provide an improved process of electrodepositing nickel involving a novel class of addition agents which will not only render the nickel plate desirably bright but which will also preserve or render the plate desirably ductile.

Other objects of our invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter more particularly pointed out in the claims, the following description setting forth in detail certain approved modes of operation of our process and combination of ingredients embodying our invention, such disclosure constituting, however, but certain of various forms in which the principles of our invention may be used.

Broadly stated, our invention comprises the discovery that a plurality of addition agents respectively selected from certain different classes of compounds, neither one of which will produce an entirely commercially satisfactory plate when used alone, are cooperative in their action and when used in combination in conventional acid nickel baths, will produce a bright and commercially ductile plate. k

Since these two classes of compounds are intrinsically and functionally distinct, they will be described separately, being identified respectively as (1) "aromatic amino compounds" and (2) "aromatic sulfon-compounds.

AROMATIC AMINO COMPOUNDS The substances comprising this class of compounds, which we have found especially suitable, may be classified as follows:

I. Dyes and dyestufls:

A. Azo dyes. B. Stilbene dyes. C. Diand tri-phenylmethane dyes. D. Xanthene dyes. E. Acridine dyes. F. Thiazole dyes. G. Indamine, Indoaniline and Indophenol yes. H. Azine dyes. I. Oxazine dyes. J. Thiazine dyes. K. Oxyquinone and Oxyketo dyes.

II. Alkalm'ds. III. Other aromatic amines.

The salts of the above referred to dyes, such as chloride, hydrochloride, acetate and sulphate, are usually preferable to the referred to type of dyes themselves because of their greater solubility.

Reduction products and substitution products or many of the referred to types of dyes and other compounds are suitable and, in some cases, superior to the compounds themselves. It is to be understood that such members of the above groups as are not soluble in the nickel bath cannot be used.

Some specific examples of the aromatic amines which have been found to give good results are as follows:

SUBSTANCES salt employed being indicated.

TABLE I I. Dyes and dyestufls A. Azo dyes 1. Pontachrome Blue R (1'-hydrox-1,2'-azonaphthalene-4,4'-disulfonate of sodium) 0.05-0.10 g./l. (208) 2. Direct Blue D3B (sodium 3,3'-dimethyldiphenyl-4-.azo-2.' (8' '-a.m.ino-1) (-napl1- thol-3",6"-disulfonate) 4' azo 2" (8'f-amino-1"-naphthol 3",6'" disulfonate) )0.025-0.05 g./l. (471) 3. Brilliant Croceine 3BA (sodium azobenzene-4-azo-1"- (naphthol-2" disulfonate-6",8") )0.025-0.05 g./l. (539) B. Stilbene dyes 1. Pontamine Yellow SX (sodium dinitro-azodistilbenetetrasulfonate) 0.05-0.25 g./l. (704) v C. Triphenylmethane and diphenylmethane dyes l. (Fuchsin) p.p'-diamino m methyl fuchsonimonlum chloride 0003-0030 g./l. (780) 2. Triaminotolyl diphenyl methane hydrochloride (reduction product of Fuchsin) 0.003-0.030 8J1.

3. Triaminotolyl phenyl carbitol hydrochloride (carbitol product of Fuchsin) 0.003.-0.030 g./l.

4. Mixture of reduction products and carbitol of Fuchsln prepared as hereinafter explained 0.003-0.030 g./l.

5. Malachite Green (tetramethyl-p.p'-diaminotriphenylmethane) (754) D. Xanthene dyes 1. Rhodamine S (tetramethyl-diaminosuccinylxanthylium chloride) 0.025-0.05 8./l. (863) 2. Sulfo Rhodamine B, extra (sulfonic acid of tetraethyl-diaminophenylxanthylium sulfonate, sodium salt) 0.025-g./l. (864) E. Acridine dyes '1. Rhodamine Orange (tetramethyl-diamlnoacridine hydrochloride) 0.025-0.05 g./l. (902) F. Thiazole dyes 1. Thioflavine TCN (2-(p-dimethyl-aminophenyl) -6-methylbenzothiazole methylchloride) 0.025-0.125 g./l. (934) G. Indamine, indoaniline and indnphmol dyes 1. Hansa Green GS (No chemical name nor formula given in Schultz) 0.025-0.05 g./l. (940) H. Azine dyes l. Safranine Y (mixture of ms-phenylditolazonium chloride and ms-o-tolylditolazonium chloride) 0.001-0.05 g./l. (967) 2. Induline BB or Induline R (sodium salt of sulfonated alcohol soluble Induline) 0.025-0.05 g./l. (984) 3. Nigrosine (sulfonated alcohol soluble Nigrosine) 0.05-0.25 g./l. (986) I. Oxazine dyes 1. Basic Navy Blue D (dimethylaminophenonaphthazoxonium chloride) 0.025-0.050 8J1. (1025) J. Thiazine dyes 1. Methylene Blue or Calcozine Blue 2F EX (tetramethyldiaminodiphenazthionium chloride) 0.02-0.05 g./l. (1038) 2. Methylene Green BD or Calcozine Green (tetramethyldiaminonitrodiphenazthionium chloride) 0.025-0.05 g./1. (1040) 3. Toluidine Blue (dimethylaminophenoaminotolazthionium chloride) 0.025 g./l. (1041) 4. Thionine Blue S0 (trimethylethyldiaminodiphenazothionium chloride) 0.025 g./l. (1042) 5. New Methylene Blue or Calcozine New Blue N (symmetric diethyldiaminoditolazthionium chloride) 0.025 g./l. (1043) 6. Thiocarmine R (sodium salt of sulfonic acid of symmetric 'diethyldibenzyldraminodiphenazthionium sulfonate; internal sulfonate) 0.025 'g./l.' (1044) 7. Brilliant Alazarine Blue GA (dimethylamino-dihydroxynaphthophenazthionium sulfonate and/ or benzyl-ethylaminodihydroxy-naphthophenazthionium sulfonate) 0.025 g./l. (1048) K. Oxyquinone and ozylceto dyes 1. Newport acid Anthraquinone Blue AB (4,8-diaminoanthrarufln 2,6-disulionic acid: soda salt, and/or 1.5-dloxy-4,8-diaminoanthraquinone 2,6 disulfonic acid; soda salt) 0.05-0.25 SJ]. (1187) aasaeei II. Alkaloids A. quinine bisulfate 0.008-0.020 g./l.

B. Nicotine sulfate 0.004-0.010 g./l.

C. Brucine sulfate 0.002-0.008 g./l.

D. Cinchonine sulfate 0.005-0.010 g./l.

Other Aromatic amines A. Benzidine acetate 0.004-0.010 g./1.

B. 2,4 diaminophenolhydrochloride 0.005-

C. m-Toluylenediamine 0.005 g./1.

D. O-m-and p-,Phenylenediamine sulfate E. Phenylhydrazine 0.02 g./l.

F. Pyrrole 0.05-0.10 g./l.

G. Aminoazobenzene sulfonic acid 0.005-

H. Picramic acid 0.005-0.010 g./l.

I. p-Nitroaniline 0.0040.008 g./l.

We have found it most practical to prepare specific Example I-C-4 given above in the following way: Fifty parts of the dye, 1,000 parts of water, 100 parts of granular nickel and 100 parts of hydrochloric acid are heated and mechanically stirred until the magenta color of fuchsin has practically disappeared. The mixture is then stirred with a small amount of activated carbon and filtered. The filtrate is made up to one liter and contains the equivalent of five grams of the original fuchsln per 100 cc.

While the quantities of the substances listed in Table I are not sharply critical, they are used in small amounts as indicated by present preferred ranges indicated opposite each compound listed, the lower limit being determined by the desired brightening effect and the upper limit being determined by the embrlttling effect or, in some cases, solubility in the nickel bath. These compounds are capable of producing, in the absence of compounds of the second class, deposits which are bright but brittle, and are used in quantities less than required to produce maximum brightness in the absence of any compound of the second class. The brightness produced by these compounds alone is often accompanied by other defects in addition to brittleness such as "streaking, burning, etc. Most of the examples given in Table I are commercial products. In general, impurities are undesirable, however, mixtures of these brightening agents are usable and are within the contemplation of the invention.

The second class of materials, representative particular ones of which are employed in combination with one or more substances of the first class of compounds above identified, may be and for the purposes of this specification are designated as aromatic sultan-compounds. These materials are capable of cooperating with the materials of the first class to produce nickel deposits having a high order of brightness accompanied by commercial ductility. Particular examples which we have found to give excellent results are as follows:

III.

TABLE II Alpha-naphthalene mono-sulfonate Beta-naphthalene mono-sulfonate Naphthalene disulfonates Naphthalene trisulfonates Sulfonated naphthalene o-Benzoic sulfimide (saccharin, preferably as sodium salt) Benzene sulfonamide Benzene sulfohydroxamic acid 9. p-Toluene sulfonamide 10. o-Toluene sulfonamide The above named addition agents of this second class, suitably in the form of the sodium or the nickel salt, may be used in various quantities upwards from 0.2 g./1., however, 5 g./l. or less is usually sufficient concentration for best results. Larger quantities, within the limits of solubility, do no harm.

Specific Example 5 of Table II above is such as may be produced by reacting 2 parts of 20% oleum on one part of naphthalene at C. for two hours, neutralizing the resulting mixture with nickel carbonate, filtering and diluting to 26 B. Where quantities of "sulfonated naphthalene" are referred to hereinafter, it is to be understood that the quantity specified represents roughly the nickel-naphthalene-mixed-sulfonate content of the mixture. Five cc. of the nickel neutralized reaction mixture is taken as equivalent to one gram of nickel-naphthalene-mixed sulfonates. This treatment produces, as is well known, a mixture containing nickel naphthalene monosulfonates, disulfonates and trisulfonates.

A conventional aqueous acid nickel bath in which the combined use of the two classes of addition agents will be found to give improved results, as above indicated, consists of:

N1SO4.6H2O" 120-450 grams per liter NlClaGHzO 15-75 grams per liter 15 grams per liter to H3303 saturation Sodium lauryl sulfate"-- 0-1.0 grams per liter Current density Up to 60 amperes per sq. ft. pH 1.5-5.5 Temperature Room to F.

Where this compound is given, the material sold under the trade name of Duponol M. E. Dry is to be understood. It is sold as the technical compound. Other equivalent surface tension reducing agents may be used instead of Duponol. Preparations known as Tergitol 7 and Tergi tol 08, sold by Carbide & Carbon Chemicals Co. and said to be sodium secondary alcohol sulfates, may be used instead of Duponol. The quantities required are of thesunie order.

"Some heptahydrate is usually present. Where nickel sulfate is used herein in specific examples, this mixture or hydrates is to be understood.

In the above table giving the composition of a conventional bath, sodium lauryl sulfateis added for the purpose of reducing the surface tension in order to prevent pitting of the plate. The sulfates of normal primary aliphatic alcohols, having from 8 to 18 carbon atoms, are a class of compounds preferred for use for this purpose. 7

Following are a number of specific examples .of bath compositions, each liter of which contains the substances indicated. a

PAa'rrcuLsa Eksmrms That is, the reduction roduct f .0 unreduced dye. p 0 00 gram of the Example 'No. 6

v 4 2,2$6,ae1

Example No. 2 Example 1V0. 7

Nickel sulfate "grams" 240 gigt ii fi "f Nickel chloride do 37.5 B 6 Boric acid do 37.5 5 23 E 1 sodium lauryl sulfate do. .25 e Pontacyl Green B do.. 0. 1 g g i p sulfate 0-010 Sulfonated naphthalene (nickel :5 summlde salt) "grams" 4.0 um. Sam L0 W at er to makp Mn" 1 Sodium lauryl sulfate (technical) do 0.25 pH 4 0 Water to make "liter" 1 a H 3-4 5 Temperature C..- 50-60 D Current density amp./sq. It-.. 40 Temperature 45-55 Current density amp./sq.ft 30-40 Example No. 3 Example No. 8

Nickel sulfate grams 240 Nickel sulfate --8 240 Nickel chloride do 37.5 Nickel do 37.5 Boric acid do 37. 5 3 '1 Sodium lauryl sulfate d0 g Fuchsln 01,25 Reduced Fiinhuln d0 *0. 005 sogl l g li g Beta-naphthalene monosulfonate (sodiamyks ate (technical) um salt) grams-.. 2.0 pH er 0 ma 8 Water to mak 1 Tem tu nc PH 0 Current density amp./sq.fl; 40 2:2 :3 ggg z; 5557; g" 2: z gf s. e reduction product of .025 g. o: the unreu Example N0. 9

That is, the reduction product of 0.005 g. of the Nickel sulfate grams 240 unreduced dye. Nickel ChlOI' fl (10 37.5 Example N0. 4 Boric acid do 37.5 Reduced Fuchsin ....do 0.005 Nickel S f Benzene sulfohydroxamic acid do 2 0 Nickel chloride d0- Water to make llter 1 Boric acid do 37. 5 P 3.5 Sulfonated naphthalene (nickel T perature c 45-50 salt) "grams" 4. 0 Current density amp./sq.tt 2.2, 4.4 Tetramino 5.5 dimethyldid {shalt is, the reduction product of .005 g. of the antephenylmethane sulfate gram .010 40 Water to make liter 1 Example 10 Temperature C -47 el Sulfate grams 240 Current density amp./sq. ft 36 Nickel chloride pH 2 5 to 4 5 Boric acid dn 37.5 45 Reduced Fuchsinv do- 0.005 Ezample No. 5 p-Toluene sulfonamide .do 1.0 Water to make litpr 1 Nickel sulfate rams-- 2 pH 4.0 Nickel chloride do 37.5 Temperature C -55 Boric d do 37.5 50 Current density amp./sq.tt 40 sodium lauryl sulfate d0.. 25 d 'l hgt is. the reduction product or .005 g. of the unre- Reduced Fuchsin d0-- 2 Mixture of alpha and beta naphthalene Exam) 16 11 mono sulfonates (free acid) grams 20 Nickel sulfate gra.ms 240 Water to make 1i*er 1 kel hloride do 37.5 pH 2 0 Boric acid dn 37.5 0 Reduced Fuchsin do '0 005 Temperature (2.. 55-65 It 40 o-Toluene sultonamide do 1.0 Current density p Water to make "liter" 1 I 4.0 That is, the reduction product of .002 grain of the Temperature 0C unreduced (lye.

Current density amp./sq.i't 40 That is, the reduction product of .005 g. of the unre- (luced dye.

Nickel sulfate --srams 240 Example No. 12 Nickel cimonde "3 7"" Nickel sulfate gra,ms 240 Nickel chloride do 37.5 Sodium Su B i d Reduced Fuchs -010 Fu h i dn 0 015 Sulfonated naphthalene nickel salt) Q-Benzo1c summide 39 s Sodium lauryl sulfate do 0.25 Water to make 1 Water to make liter 1 pH n 2.0 pH Temperature --C-- 55-65 Temperature 0.; 55-60 cu -em; density --amp./sq.ft-- 40 Current density --amp./sq.rt-- 60 trample No. 13

Nickel sulfate zrams..- Nickel chloride. do.. Boric acid do Sodium uobenaene-4-asc-i'.'-

(naphthol-2"-disulfonate-6".8")

(Brilliant Croceine 83A) do "Sulfonated naphthalene (nickel salt) do Water to make .1iter. pl!

Temperature C..- Current density amp./sq. ft

Esample No. 14'

Nickel sulfate "grams" Nickel chloride ....do Boric acid do Tetra-methyldiaminosuccinylxanthylium chloride (Rhodamine S). srams Sulfonated naphthalene" (nickel salt) do Sodium lauryl sulfate -do Water to make ...liter 9" Temperature C-..

Current density ..-amp./sq. ft

Example No. 15

Nickel sulfate grams Nickel chloride do Boric a do Mixture of ms-phenylditolazonium chloride and ms-o-tolylditolazonium c h 1 o rid e (Safranine Y) "grams" o-Benzoic sulflmide (saccharin, sodium salt) "grams" Sodium lauryl sulfate "do..- Water to make liter.. DH Temperature C Current density ampJsq. it

Example No. 16

Nickel sulfate grams..-

Nickel chloride ..-do-.. Borlc arid do Dimethylaminophenonaphthazoxonium chloride ,(Basic Navy Blue D cone.)

Tetramethyldiaminodiphenazthionium chloride (Methylene Blue, extra, cone.)

grams..- Sulfonated naphthalene" (nickel salt) grams Sodium lauryl sulfate do Water to make liter pH Temperature C Current density amp./sq. ft-..

a,aaa,ee1 5 A Example No. 18

Nickel sulfate "grams" 240 37,5 Nickel chloride do-.. 37.5 375 Boric acid do 37.5 Tetramethyldiaminonitrodiphenazthionium chloride (Methylene Green BD) grams 0.025 0 5 "Sulfonated naphthalene (nickel salt) grams-.. 4.0 44) Water to make liter 1 1 pH 4.0 49 Temperature C-.. 50 50 Current density amp./sq. ft 40 Example No. 19

Nickel sulfate "grams" 240 240 Nickel chloride do 37.5 315 Boric a dn 37.5 20 Quinine bisulfate. do 0.010 p-Toluene sulfonamide do 1.6 o 025 Sodium'lauryl sulfate do 0.25 Water to make liter 1 4 0 pH 4.0 0 Temperature C 55 1 Current density amp./sq. ft

Example No. 20

Nickel sulfate grams 240 Nickel chloride do 37.5 Boric a do 37.5 Nicotine sulfate do 0.010 2 Benzene sulfohydroxamie acid do 2.0 Sodium lauryl sulfate "do 0.25 Water to make liter 1 PH 4.3 Temperature C. 60 Current density amp./sq. ft 40 2.0 40 E a 0.25 a: mple No 21 1 Nickel sulfate grams 240 4.0 Nickel chloride do 37.5 Boric acid do 37.5 40 Benzidine (dissolved with aid of acetic acid) grams 0.01

Sulfonated naphthalene (nickel salt) grams 4.0 240 Water to make "liter" 1 pH 4.0 r 50 Temperature C 50 Current density "amp/sq. ft 40 0-030 Example No. 22

4.0 Nickel sulfate grams 240 1 Nickel chloride n do 37.5 4.0 Boric acid do 37.5 50 m-Toluene diamine do 0.005 40 SulfOnated naphthalene do 4.0 Water to make liter 1 pH 1 4.0 Temperature C 50 g Current density amp./sq. ft 40 37.5 5 Example No. 23

Nickel sulfate grams 240 0,025 Nickel chloride do 37.5 Boric acid "do 37.5 5,0 7 Picramic acid do 0.005 0.25 "Sulfonated naphthalene do 4.0

1 Water to, make liter 1 3.3 DH 4.0

0 Temperature C 50 5o Current density ampJsq. it" 40 Having thus described our-invention, what we claim is: I. A nickel plating bath comprising an aqueous, acid solution of a nickel electrolyte of the class consisting of nickel sulfate, nzickel chloride and mixtures thereon said solution having the capability of producing bright and ductile deposits of nickel, such capability having been imparted thereto by the inclusion therein 01 cooperating addition agents, one of said addition agents consisting of one or more aromatic amino compounds soluble in the bath to the extent of at least 0.002 gram per liter and characterized by a brightening and embrittling tendency at a concentration between 0.002 and 0.10 gram per liter, the other of said addition agents consisting of one or more sulfur containing aromatic com- Pounds soluble in the bath to the extent 01' at least 0.2 gram per liter selected from the group consisting of the naphthalene mono-, di-, and trisulionates, benzene sulionamides, toluene sulfon'amides, ortho benzoic sulflmides (saccharin. soluble saccharin) and sulfohydroxamic acid and characterized by a ductilizing tendency, said first mentioned addition agent being maintained in solution in concentration from 0.002 to 0.10 gram per liter and said second mentioned addition agent being maintained in solution in concentration above 0.2 gram per liter, said addition agents cooperating to produce bright and ductile electrodeposits of nickel.

2. A nickel plating process comprising electrolyzing an aqueous, acid nickel electroplating solution containing one or more nickel compounds of the class consisting of sulfate and chloride and an addition agent of each 01' two classes, one of said classes consisting of those aromatic amino compounds which are soluble in the said electroplating solution to the extent of at least two milligrams per liter, and which are characterized by a brightening and embrittling tendency at a concentration between 0.002 and 0.10 gram per liter and the second of said classes consisting oi. naphthalene mono-, di-, andtrisulionates, benzene suli'onamides, toluene sulfonamiides, ortho benzoic sulilmides (saccharin, soluble saccharin) and su1- iohydroxamic acid, one or more compounds 01' the first of said classes being maintained in solution in quantity such as would, in the absence of a ductilizing agent, produce an embrittling effect on the resulting deposit and one or more compounds of the second class being maintained in solution in quantity to render the deposit ductile, said addition agents cooperating to produce bright and ductile deposits of nickel.

3. A nickel plating solution containing one or more nickel compounds of the class consisting of sulfate and chloride, at bufiering' agent, and one or more addition agents of each 01 two classes, one of said classes consisting of those aromatic amino compounds which are soluble in the said electroplating solution to the extent of at least two milligrams per liter and which are characterized by a brightening and embrittling tendency at a concentration between 0.002 and 0.1 gram per liter, and the second of said classes consisting of naphthalene mono-, di-, and trisulfonates, benzene sulfonamides, toluene sulfonamides, ortho benzoic suifimides (saccharin, soluble saccharin) and benzene sulfohydroxamic acid, one or more compounds 01' the first of said classes being maintained in solution in quantity from 0.002 to 0.10 gram per liter and one or more compounds of the second of said classes being maintained in solution in quantity from 0.2 to 5.0 grams per liter, said addition agents cooperating to produce bright and ductile electrodeposits of nickel.

RUDOLF LIND.

WILLIAM J. HARSHAW.

KENNETH E. LONG.