Proceedings of the Polytechnic Association. 845 



Devil's tears, which were sohl as toys a few years ag-o, and certainly 

 it is surprising that any sensil)le man should reconimcnd them for an 

 article of such common use as matches. 



Ce:\ient to Resist a Red Heat and Boilixg Water. 

 A Gei'man journal gives two processes for malting these cements: 

 1st. To four or live parts of clay, thoroughly dried ;md |»idverized, 

 add two parts of iron tilings free from oxyd, one })art of ])eroxyd of 

 manganese, one-half part of common salt and one-half of borax. 

 These are rubbed together and made as line as possible, after which 

 water enough is added to make a thick paste. It mast be a|tj)lied 

 immediately and then gradually heated almost to a white heat. 3d. 

 To equal parts of sifted peroxy<l of manganese and v.-ell pulverized 

 oxyd of zinc, add a sufficient quantity of silicate of soda (water glass) 

 to form a thin paste. The mixture should also be used immediately. 

 It foi-nis a cement quite as hard and duraljle as that obtained by the 

 first method. 



"WiiEX TO Sweetex Tarts. 

 Dr. Letheby, in his lectures on tViod, states that common cane- 

 sugar is adulterated in Europe by means <->f starcli-sugar or even 

 starch itself. Starch-sugar, or as it is sometimes called grape-sugar, 

 or glucose, has alow sweetening power; not half so great as tliat 

 of cane-sugar, in fact, it is produced from the the latter \)y the action 

 of vegetable acids and heat, when cane-sugar is ad<led to fruit in 

 making a tart or fruit pie, and in making jellies and jams. It is 

 false economy, therefore, to sweeten to any exteiit l)ef)re the tart is 

 baked. Some American housewives have discovered, by practice, 

 in making rhubarb pies, which requires a large amount of the sweet- 

 ening principle, that a given (quantity of sugar vrill be most effective 

 when the largest portion is applied to the pie aftei' it lias been taken 

 from the oven. 



PuROrEfUA. 



The oil known among tlie Rortugncse by this iiaiue has recently 

 been subjected to experiments ])y Bouis. It c()ntains al)out six ]ier 

 cent of nitrogen, which, on di-tillation, is cvoKhmI as aniiU'jnia. As 

 it possesses some of tlie properties of c;istor oil, and is obtained, like 

 the latter, from a plant belonging to the s])ongo family {'Hphorhhi- 

 ceo') he was led to distill it witli an alkali, and the result of a saponi- 

 fication and distillation was an infianunable conqjlcx li(piid having 



