OXIDATION OF LEAD SOLDER. 1 ] § 



In the chalks of Volhynia there are a great number of , ^- 



flints, in the form of nodules more or less large. In on^ Petrified woo4^ 

 place were found two as big as a man's fist, enclosing petri* **"" *^ * * 

 fied roots of wood. The autlior possesses one of these, the 

 wood in which has not altered in colour, and appears to be 

 beech. Another nodule found in the same place contains a 

 number of splinters of wood. 



The chalk, from which these flints were taken, analysed Analysis of tb» 

 by Mr. Haquet, gave in 100 parts, lime 47, magnesia 8, '^^^^^^ ^^* 

 carbonic acid 33, silex 7, alumine 2, oxide of iron 0*5. 



He has likewise analysed several flints from different 

 places, ^nd found them containing : 



Silex ...ff 92*75 •• 92-50.. 92-75.. 97 ••89 Analysesof 



Alumine I-IO-. .. 1-50.. 1 ..2 ^i^^s. 



Lime 1-25.. 3 .- 2-75.. 0-25«r 4-15 



Magnesia ...••• •« •. 0-51'. •• 



Oxide of iron 2 • • 1*25. . 1 • » 1 • • 1'75 



Oxide of manganese •• 0*75. • 



Mr. Haquet observes, that flints are never found at any Always near 

 nsiderable depth; and the deeper we go, tli 

 more distant from each other are the nodules. 



considerable depth; and the deeper we go, the smaller and * ^® ^"' '^^*^' 



VIII. 



Of the Oxidation of the Solder <if Leaden Vessels used in 

 Wash-houses; by J, C.X>ELA^^TiiERiE*, 



xILN enlightened amateur of the arts, Mr. Fougeray de Lead solder 



^Launai, who lives near Soissons, informed me, that Taun- *^ '"r^^^'* '** '. 



• . . Z . "" vessels used lO 



dresses, who wash geat quantities of linen, use for their washing. 



b^ucklng tubs large vessels made of se\'eral sheets of lead, 



soldered together with the common solder consisting of lead 



and tin. This solder suffers no damage, as long as the ves- 



pel is kept in use : but if it be left empty for a few months, 



the >«older is so much oxided, that the lead must be soldered 



afresh, before it will hold lie again. 1 requested prof, Vau- 



<jueiiii to examine this solder, and the following is the result. 



He found, that it consisted almost whoUy of carbonated The lead con- 



• Journal de Pbysiciue, Vol.LXllI, p. 252. September, 1806. 



I 2 ©xide 



