1852.] SCIENTIFIC INTELLIGENCE, 



SCIENTIFIC HVTELLIGENCE. 



43 



Chemis.ry and Physics. 



Coaling Metah: Henry Grissell's (of the Regent's Canal Iron-works) 

 improvement in coaling metals with other Metals. — Patent dated January 

 11th, 1851. Eiinilied J.ily lOili, 1851, (Loiulon Patent Journal.)— 

 The patentee's improvements ia coating metals with other metals are 

 BS follows : — 



Coating Iron with Zinc. — For this purpose the patentees use a bath 

 or vessel of irun, or other suitable material, in which, by means of heat 

 they melt tlie zinc, and on the surface of the melted zinc place a thick 

 lajer of cldoride of zinc (prepared by dissolving zinc in muriatic acid, 

 and dnvinij ofT the water.) i-ra mixture composed of 8 parts of chloride 

 of zinc, and 10 parts of chloride of potassium, or a nii.xt'ire of equal 

 parts of chloride of zinc and chloride of sodium, or chloride of potassium. 

 When the raetnl and the salt are in a state of fusion, the iron to bo 

 coated with zinc is dipped into the metal, th ougli the covering of 

 fused salt, and becomes coated with zinc. If, however, it is found 

 that a sullicient quantity of zinc lias not adhered to the iron a small 

 quantity of sil-aminoni:ic, in powder, is sprinkled over the iron, which 

 is again dipped into the melted zinc. Under this part of their inven- 

 tion, the patentees claim the u.=e of chloride of zinc applied as above 

 mentioned in the fused state; also of the mixtures of the various salts 

 above enumerated. 



Coating Zinc, Iron coaled with Zinc, or other Metal, with a Metallic Alloy. 

 — For this purpose the patentees u*e a vessel of iron, or other suitable 

 material, in which tlie allny is melted. One of the alloys u.sed by them 

 is composed of zinc 10 part*, tin 26 parts, and lead 5 parts. A layer of 

 chloride of zinc mixed witli an equal weight of sal-ammoniac is kept in 

 a state of fusion on the surface of the metal alloy, the temperature of 

 ■which must not be carried higher than is sufficient to keep the alloy in 

 a fluid state. The metal to be coated is dipped into the melted alloy, 

 but not allowed to remain there longer than is absolutely necessary to 

 receive a cn.iting of the alloy. The patentees use also the alloy called 

 "fusible metal," which they prefer to make as follows: bismuth 8 

 parts, lead 5 parts, and tin 3 parts ; alloys of other compositions will 

 do, provided that their melting points are below 4110 deg. Fah. The 

 patentees claim the u.se, in the manner above stated, of the alloys spe- 

 cified and r^fer.ed to, and of the method above described for coating 

 metals with such alloys. 



Coating Iron or other Metal with Tin, or Tin alloyed with Lead. — For 

 this purpose the patentees nse a vessel of iron, or other suitable mate- 

 rial, in which the tin aUoy is melted, and on the surface of tlie fu.sed 

 metal lay a stratum of chloride of zinc, mixed with about its own 

 weight of sal-.inimoniac. The metal to be coaled is then dipped into 

 the raetnl liquid or alloy, until the coating is effected. The patentees 

 itate that it will be found advantageous, in the use of this and the 

 preceding processes, to dip the metal to be coated several times, in ol- 

 der that it may come in contact often with the layer of fused salt ; 

 also advantaaieous in the preceding process to dip the iron or other 

 met.il into a hot and slightly acid solutionof chloride of zinc, previous 

 to immersion in tlie bath of me ted metal. The patentees claim, under 

 this he.id of their invention, the use of a mixture of chloride of zinc and 

 lal-amnioniac forming a saline compound, which is kept in a state of 

 fusion on the surface of the melted tin or alloy, in the process of coating 

 metals with other metals. 



Coating Iron or other Metal with Silver, or Alloy of Silver and Copper. 

 In this case, the surface of the iron or other metal to be coated is to 

 be amiilganiated in the usual way. The patentees prefer to use for the 

 amalgamating procee-s a mixture of 12 parts o; morcury, 1 of zinc, 2 of 

 aulphale of iron, 2 of muriatic acid, and 12 of water; the mixture to 

 be heated, and, when 200 deg. Fah., the iron to be amalgamated is 

 placed in the mixture, and the mercury rubbed on the .>ur(ace of the 

 iron. The silver, or alloy of silver, is then melted in a crucible, placed 



in a suitable furnace, and the amalgamated metal is dipped into it un- 

 til it has a proper coating of silver or alloy employed. 



Under this head, the patentees claim the process of coating iron or 

 other metal or silver, or alloy of silver and copper, by amalgamating 

 the surface of the metal to be coated, and then putting it into the 

 melted silver or alloy. 



Coating Iron with Copper, Brass, or any alloy of Copper, with Zinc, 

 Tin, or Lead. — In this case, the copper or alloy used is melted in some 

 suitable vessel, and on the surface of the melted metal is placed a 

 Inyer of borosilicate of lead, (composed of 112 parts of oxide of lead, 

 24 of boracic acid, and 16 of silica,) and when the metal and the salt 

 are in a state of fusion, the metal to be coated is introduced through 

 the layer of salt into the melted metal, where it is allowed to remain 

 long enough to acquire a coating of the metal. The patentees some- 

 times coat the iron with zinc, or with tin, or even amalgamate its sur- 

 face with mercury, in the way above mentioned, and then proceed to 

 dip it into the melted copper or alloy. Another method of coating 

 iron with copper or brass, is that of exposing it to the vapor of chloride 

 of copper, by placing that substance at the bottom of a copper cruci- 

 ble, in the upper part of which is placed the iron to be coated. The 

 crucible ia heated to redne.ss, in a suitable furnace, and the vapors of 

 chloride volatilize and coat the iron with copper. If the iron thus 

 coated with copper be placed in the upper part of a covered crucible, 

 in which meialic zinc, covered with animal and other charcoal, is 

 placed, and heat applied as in the above case, the vapors of the zinc 

 rise, and coming in contact \rith the copper-coated iron, convert the 

 coating of copper into brass. Instead of chloride of copper, a mixture 

 of metallic copper and sal-ammoniac may be used, or a mixture of 

 oxide of copper and sal-ammoniac. 



The patentees claim under this head of their invention, the use of 

 borosilicate of lead, in a fluid stale, over a surface of melted copper or 

 bra,ss, or of the alloys ab ive mentioned, in the process of coating iron 

 by immersion ; a'.so, the process of coating iron by the action of fused 

 chloride i f copper, or the mixtures above named, and of coating with 

 brass by subsequent treatment with vapors of zinc, as above mentioned, 

 — Silliman's Journal. 



On Rain lFa^er.5.— M. Chatin makes the following statements as re- 

 sults of his operations : — 



1. The chlorides which abound in the rains of maritime countries, 

 are at Paris more abundant than in the waters of the Seine whenever 

 the wind blows from the sea. 



2. Sulphates exist in a notable quantity in the rain of Paris and ia 

 that of Central France ; rain waters, thoui^h generally containing less 

 of chlorides than the waters of rivers, usually surpass the latter in th» 

 proportion of sulphates. 



3. Salts of lime and soda are contained in rain watera in an appre- 

 ciable quantity. 



4. Rain waters are especially distinguished by containing even half 

 a decigramme to a litre of azotized organic matter, which may b« 

 represented in its composition by a mix'ure of ulmate of ammonia 

 and uUnic acid ; this ingredient is found also in the lower strata of tli« 

 atmosphere, (thou'.;h less m Turin and on the borders of the sea than 

 at Paris and in Maurienne,) whence it is deposited by the dews and 

 mists, and may be separated by washing. 



5. Argillaceous earths retain better than lighter soils this principU 

 dissolved in rain waters. The atmosphere, and the rains which wash 

 it, perform an important part in agriculture, in restoring to the soil a 

 portion of soluble mineral and organic matters highly useful to 

 vegetation. 



Dr. Kemp's Eleelro- Magnetic Engine.— S. summary account of this 

 invention was given in the Mijiing Jownal for the lOth of January 

 last ; and, as the subject is one of considerable importance, a mor» 

 extended notice will probably be read with intsreat. The prodigioui 



