THE MONTHLY BULLETIN. 79 



Solder (equal parts of tin and lead) — The strip of solder, weighing 

 about 37 grams, lost 0.2696 grams during a period of 88 days' exposure, 

 being an average daily loss of 0.003172 grams. 



Tin-plated Iron — This strip, weighing about 4 grams, showed about 

 the same daily loss as the block tin for the first two weeks, when most 

 of the tin plating seemed to have been removed. The loss for the 

 remainder of the 88-day period was almost negligible, here again 

 showing the slight influence of cyanide upon iron. 



Interpreting the above results it seems reasonable to conclude that 

 a tank constructed of sheet iron would be a suitable container as far as 

 the action of the cyanide is concerned. The only objection to this is 

 its susceptibility to rust from the outside. 



A tank constructed of tinned iron with soldered joints would not be 

 so subject to rust from the outside. The tin plate would be soon eaten 

 away from the inside and the solder would be very slowly dissolved, 

 but this latter action is very slow so that a tank of this sort would last 

 for a long time. Ordinary 5-gallon coal oil and gasoline cans have been 

 used with satisfaction for carrying the cyanide solution into the field 

 and emptying into the supply tank of the machine. These cans are still 

 in good shape after three months' use. 



Block tin and lead are slowly but constantly dissolved by the cyanide 

 solution, are expensive, and offer no advantages over the above. 



Zinc, Copper, Aluminum, Brass — Strips of these were almost com- 

 pletely dissolved in ten days, with the exception of the brass, in which 

 case the solvent action is somewhat slower, but also very rapid. These 

 metals are absolutely unsuitable for the purpose. 



Galvanized Iron — The coating of zinc was entirely dissolved in a 

 few days. This material, then, possesses no point of superiority over 

 iron and also has the disadvantage that the zinc is soon dissolved away 

 at the joints and permits leakage. 



Treatment of Wooden Containers. 



A variety of substances was experimented with in order to find a 

 suitable material for the treatment of wooden tanks or barrels. 



Rosin varnish, asphaltum varnish, shellac and paint are completely 

 disintegrated by the cyanide. 



Both animal and vegetable fats and oils are saponified by the action 

 of the cyanide. 



Paraffin, however, is not affected to an appreciable extent and would 

 be a very suitable material for the treatment of wooden tanks or barrels. 

 The wood should be untreated with any other substance and must be 

 dry. The paraffin must be applied hot. A very satisfactory method for 

 treating a barrel with paraffin has been tried out in a commercial way 

 by the speaker, although for another purpose. 



In this case the containers to be treated were 5-gallon kegs of soft 

 pine. About 2 quarts of paraflln were melted and poured into a keg 

 while hot. The bung was closed and the keg rolled and turned over 

 in such a way that the melted paraffin came in contact with all parts of 

 the interior. The heat of the melted paraffin was found to be sufficient 

 to prevent its solidification to any great extent. The bung was removed 

 and the excess of paraffin poured out and reheated for the next keg, 

 more paraffin being added from time to time to maintain a volume of 



