1865.] 



CANADIAN MAKBLE.— ON THE SEPARATION OF SILVER FROM LEAD. 



221 



ing the past season some have realized as high as five hundred, seven 

 hundred, eight hundred, and eight hundred and fifty gallons to the 

 acre. 



The success in producing wine from this grape is in some measure 

 to be attributed to the greater length of the seasons and the character 

 of the soil in this vicinity. It being absolutely necessary to make wine 

 from this or any other grape, that it should reach the degree of ripe- 

 ness or maturity which will furnish the requisite amount of sugar or 

 saccharine matter to preserve the wine by its conversion into alcohol 

 in the process of fermentation. Grapes maybe considered ripe enough 

 for eating, which would not do for wine making. 



Substitutes for Citric and Tartaric Acids, and tliclr Salts. 



Gatty and Kopp employ lactic acid and the lactates. This acid, 

 when used as a resist, is thickened with starch, and then printed by 

 block or roller upon cloth, which is afterw.ards printed or padded with 

 mordants. One gallon lactic acid at 40° Twaddle is used, instead of 

 one gallon lemon-juice at 50° Twaddle. In cases where the lemon- 

 juice is previously saturated with an alkali, the lactic acid is treated 

 in the same manner. 



When lactic acid is used as a discharge, it is thickened as in the above 

 case, and printed upon cloth saturated with mordants, which it dis- 

 charges by forming soluble salts with the oxides constituting the mor- 

 dants. In using lactic acid to precipitate carthamine from the alkaline 

 solution of safflower, 4 lbs. acid at about 40° Twaddle are used in place 

 of 3 lbs. tartaric acid. In dyeing Prusian blue, scarlet, crimson, &c., 

 on silk or wool, tartaric acid or cream of tartar is generally used. In 

 such cases, lactic acid or bilactate of soda is applied, and the manipu- 

 lations are the same as when tartaric acid is ured, 1:^ lbs. bilactate of 

 soda at 66° Twaddle serving for 1 lb. cream of tartar. When lactic 

 acid is employed for steam colours, it is substituted for tartaric acid 

 in the proportions already stated, the preparations of the colours being 

 the same as when tartaric acid is used. Lactic acid may be applied in 

 preparing white and coloured discharges upon Turkey red and other 

 colours ; the operation is managed just as if tartaric acid were used — 

 only, after printing, the cloth should not be exposed to a long-con- 

 tinued heat, which, owing to a slight volatilization of the lactic acid, 

 would reduce its discharging properties. 



Belford's process depends upon the formation of an artificial tartaric 

 acid by mixing oxalic acid with sugar, a substance containing the exact 

 proportion of hydrogen in which oxalic acid is deficient. A quantity 

 of sugar or treacle is drenched with nitric acid, and with some mother- 

 water in which oxalic acid has been crystallised. As soon as nitrous 

 vapours cease ascending, more nitric acid is added, and the solution is 

 then concentrated until a crystalline mass is obtained on cooling. This 

 mass consists of slender crystalline needles, and is next washed for 

 obtaining the acid. After washing the crystals, add sugar which has 

 been dissolved in some of the washing liquor, the quantity of sugar 

 required being proportional to the degree of acidity which it is desired 

 to attain. The syrupy fluid is then concentrated at a gentle heat, and 

 left to crystallise at a moderate temperatui'C. Or, take one part of 

 sugar or treacle, and add one-third acetic acid, and three parts nitric 

 acid at 36° Twaddle. This yields an oxalic acid containing more 

 hydrogen than the common oxalic acid (? !). The crystals obtained 

 from this solution are purified by washing and re-crystallisation. The 

 oxalic acid thus obtained may be converted into tartaric acid by deoxi- 

 disation. This is effected by dissolving sugar in the washing liquor 

 and mixing with the acid. The solutions, when concentrated at a low 

 temperature and crystallised, yield so-called "tartaric" acid. The 

 ■wash liquors when concentrated may be used as mordants. 



Murdock substitutes for cream of tartar, and for the mixture of 

 cream of tartar with alum, common salt with nitric acid, and sulphate 

 of alumina. 100 lbs. salt are mixed with 300 lbs. of water, and when 

 dissolved, 20 lbs. nitric acid are introduced. When alum is required, 

 100 lbs. sulphate of alumina are gradually added. The water should 

 be cold, and the mixture but slightly stirred. 



Canadian Marble* 



We have been favoured with some hand specimens of different vari- 

 eties of marble from the quarries of Messrs. NichoUs & Co., in the 

 township of Marmora. The marble is within two feet of the surface of 

 the ground. The river Moira runs across the corner of the lot on which 

 the quarry is situated, and offers available power for the requisite 

 machinery in a marble manufactory. The distance of these quarries 

 from Cobourg is about 50 miles, and from Belleville nearly 30 miles. 



From the circumstance of their proximity to the Marmora iron works, 

 it is probable that the distance from a port will not long continue to 

 be a serious obstacle against the general adoption of Canadian marble 

 for ornamental and useful purposes. It is not generally known that a 

 large supply of very good mai ble can be obtained from many parts of 

 Canada. Notices of localities where marble may be procured are 

 interspersed throughout the Reports cf the Geological Commission : — 

 Mr. Logan says that, some beds of the Chazy limestone in the neigh- 

 bourhood of Montreal are known to take a moderately good polish, and 

 they are cut into slabs for the purpose of chimney-pieces, and occa- 

 sionally for tables, one of which, manufactured by Sir. Hammond of 

 Montreal, and sentto theLondon Industrial Exhibition of 1851, attracted 

 attention, and was readily sold. The colour of these slabs is a dark 

 grey ; in some parts of the district the grey shews occasional spots of 

 red, as on Madame Nolan's farm at Ste. -Catharine, and on Isle-Bizard ; 

 but in seigniory of La-Chenaye, on the Little River, about a mile from 

 St. -Lin, massive beds of the formation become almost wholly red, and 

 give large slabs of a very handsome aspect. The beds are ccmposed 

 of a mass of comminuted organic remains, consisting of shells and 

 corals, the latter predominating, and the prevailing species being 

 ChMiles lycoperdon. The corals are coloured ochre-red, while some of 

 the shells approach rather a rose-red, and parts of the stone are mot- 

 tled with a greyish-red running irregularly over the surface. A large 

 supply of this marble might easily be procured. 



On the Sepaeation of Silvee from Lead. — At a meeting of the 

 Royal Cornwall Polytechnic Institute, Mr. J. A. Phillips, of London 

 (formerly of the Museum of Economic Geology), said that one of the 

 most important improvements which had recently been made in the 

 metallurgical .art came into operation last year, and is the separation 

 of silver from lead by means of zinc. After describing the old process 

 of separation, and the subsequent process discovered by Mr. Pattin- 

 sou, of Newcastle-on-Tyne, involving several crystallisations and a 

 final cupilation, he stated that still more recently a patent had been 

 taken out by Mr. Parkes for a process by which he separates the sil- 

 ver entirely by one operation. To do this, the alloy of silver and 

 lead is melted in the usual way in a large iron pot ; to this a small 

 quantity, a few pounds of zinc per ton, is added, the whole mixed up 

 and allowed to remain a short time. By this means the silver is 

 brought to the surface in the form of alloy with the zinc, and this 

 mixture is subsequently skimmed off and treated for the silver it con- 

 tains. In crdor to do this, the zinc is first partially separated by oxi- 

 dation, and the residual alloys afterwards treated in the cupel. In 

 connexion with the purification of metals, he might mention some of 

 his own experiments in regard to tin. The tin from Peru and some 

 other countries contains a large amount of tungstan, or wolfram, 

 which very much depreciates its value. Till recently this tin could 

 only be employed for very common purposes, .such as making tin pipes 

 and other things which did not require tin of good quality. But in 

 analysing some of this tin he happened to discover a process by which 

 the separation was very easily effected, and this process had been re- 

 cently patented. It consists in taking impure tin, containing from 5 

 to 10 per cent, of tungstan (worth £25 per ton less than tin of ordinary 

 purity), granulating it by melting it in a reverberatory furnace, and 

 allowing it to flow into a vessel containing water. This granulated 

 tin is then placed in a pan with common hydrochloric acid, which 

 may be obtained from the soda manufacturers at almost a nominal 

 price. This being heated, hydrogen gas is evolved, and a solution of 

 chloride of tin is obtained. In this operation it is necessary that 

 the tin should be present in excess ; unless it be so, a certain portion 

 of tungstan be dissolved. Should, however, the operation be carried 

 on too far, and a portion of tungstan will be dissolved, the addition of a 

 small quantity of impure tin precipitates the tungstan, and chloride 

 of tin, free from tungstan, is obtained. This is turned off into a vat, 

 in which more granulated impure tin is placed, and any arsenic or 

 antimony remaining is there deposited, and a pure solution of chloride 

 of tin obtained. From this wo have to get the chemically pure tin 

 we require, and which is quite as good as the stream tin of Cornwall. 

 Into this bath we put bars of metallic zinc, which precipitates the tin 

 in a spongy mass, when instead of chloride of tin we get chloride of 

 zinc. The tin thus produced may be fused into bars, or sold as tlie 

 best tin. The chloride of zinc must bo so used as to lower the ex- 

 pense of the whole process. To do this, it is precipitated by milk of 

 lime, or common chalk ; we then get oxide of zinc, which is largely 

 used as a pigment ; and to give it sufficient opaqueness for that pur- 

 pose, the washed oxide of zinc is heated to redness, when it is found 

 to bo equal to the ordinary oxide of zinc obtained by sublimation. 



