100 ANNUAL OF SCIENTIFIC DISCOVERY. 



pointed to examine it, as reported by M. Jacquelan, are that it is not new, nor 

 as eood as was announced ; but it had been tried and approved for five 

 years by the Lyons and Mediterranean Railroad Company ; that the Com- 

 mittee could not tell whether it was durable or not ; its cost was about twenty 

 cents for water-proofing a coat or pair of pantaloons. On the other hand, 

 M. Balard, known to all, as one of the most distinguished and careful 

 chemists of France, reports that the thinnest woollen cloths impregnated \vith 

 it are totally impermeable to water after weeks of contact with it, that the 

 water evaporates from them, and does not pass through ; that clothes which 

 had been soaked for forty-eight hours in fresh water, were as impermeable 

 afterwards as before ; but that the transpiration from the skin appears to 

 destroy the impermeability, so that it is probably applicable only to exterior 

 clothing ; finally, that there is every probability that it is lasting, as appears 

 from the certificates. M. Balard himself testifies that an overcoat worn by 

 him for five months, which had been beaten and rubbed and subjected to all 

 the ordinary usage of overcoats, remained perfectly impermeable. Clothes 

 prepared in this way are said to be softer to the touch, warmer, absorbing 

 less moisture, drying more quickly, and therefore more durable. 



It would appear, therefore, that this process, which is cheap and easily ap- 

 plicable, even after articles are made up, is well worth experimenting upon. 

 Bull. Soc. Encour., Sept. and Dec., 1855. 



Waterproofing Paper, Cloth and Leather. P. Pierre Hoffman, of Stras- 

 bourg, has taken out a patent in England for a new varnish, which, when 

 applied to the articles named in the above caption, render them, it is stated, 

 air and water-proof, while at the same time they keep dry under all varia- 

 tions of temperature in the open air, are elastic and do not become sticky 

 the latter being a fault common to a number of varnishes. The articles are 

 coated with a mixture either of siccative linseed oil and sulphur, called balm 

 of sulphur, or of a mixture of sulphur with a quantity of siccative oil, gum 

 copal, gum opal, yellow amber, resin, india rubber, and gutta percha and 

 with the essences of turpentine or naphtha, etc., these two latter keeping in 

 solution the above named substances, which may be mixed separately or at 

 the same time with the balm of sulphur. 



The chief features of the invention consist in the use of the balm of sul- 

 phur for rendering fabrics air and water-proof, and in preparing the balm in 

 the following manner : When the siccative or common drying oil has boiled 

 for about two hours, in order to thicken it and separate its mucilaginous 

 parts it is left a few days to settle, previous to dccantation; then ten parts, 

 by weight, are taken and submitted to slow boiling, during which small 

 quantities of flowers of sulphur are added, and agitation is kept up the whole 

 time. When from one to two parts of flowers of sulphur have been thus 

 thrown in small quantities into the oily mixture, a transformation soon takes 

 place, and the balm of sulphur now assumes a homogeneous mass of a 

 brownish color, cohesive and elastic, somewhat like india rubber. The con- 

 stituents of this composition or coating are then the following (by weight) : 

 Ten parts of siccative thickened linseed oil, and from one to two parts of 

 sulphur in powder. The balm of sulphur, thus prepared, is used as the 



