CURRENT TOPICS. 529 foundries to designate any metal that is red, casts well, and cuts freely. Mixture. Copper ............. 85 Tin ................. 5 Zinc ................ 5 Lead ............... 5 A cheapermixture. Copper ............. 85 Tin ................. 3 Zinc ................ 9 Lead ............... 3 Statuary Bronze.--The best metals obtainable are selected and the best mixture known is always employed for statuary, on account of the enormous expenditure for labor, which forbids any economy in metal. The mixture is: Copper ............. 90 Zinc ................ 3 Tin ................. 6 Lead ............... I The small quantity of lead is necessary to impart the required chasing qualities to the statue. Mixture for trolley wheels: Copper ............. 92 Zinc ................ 2 Tin ................. 6 No lead is used here, as it has been shown that this mixture gives a far greater mileage than one which contains lead. Mixture for pattern castings: Copper ............. 88 Zinc ................ 2 Tin ................. 8 Lead ............... 2 Good metals are necessary for pattern bronze. They come out of the sand bright and clean. ¢ Preservatives for Butter and Margarine. K. FISCHER AND O. GRUENERT. (Zeit. Unters. Nahr. Genussm., xxii, 553.)--The re- sults of numerous experiments showed that common salt is the best preservative of butter and margarine. Specimens containing 3 per cent. of salt were quite fit for consumption after the lapse of three months, whilst other specimens which had been treated with benzoic acid, salicylic acid, boric acid, etc., had rapidly become ran- cid. With the use of salt the decomposition of the fat and casein was practically, though not quite, inhibited, but the other preservatives failed to stop this decomposition even when (in the case of butter) as much as I per cent. was added. Light Emitted by Fireflies. P. SINGH and S. MAULIK. (Nature, lxxxviii, III.)--A number of fireflies were placed over a photo- graphic plate and various materials interposed. The plate was affected through thin layers of wood and leather, but not appreciably through glass. Thus the rays emitted by fireflies are in some respects analogous.to RSntgen rays and ultra-violet light.

Light emitted by fireflies

Download PDF Report

View
219
Download
3

Embed Size (px)

Citation preview

CURRENT TOPICS. 529

foundries to designate any metal that is red, casts well, and cuts freely.

Mixture. Copper . . . . . . . . . . . . . 85 Tin . . . . . . . . . . . . . . . . . 5 Zinc . . . . . . . . . . . . . . . . 5 Lead . . . . . . . . . . . . . . . 5

A cheaper mixture. Copper . . . . . . . . . . . . . 85 Tin . . . . . . . . . . . . . . . . . 3 Zinc . . . . . . . . . . . . . . . . 9 Lead . . . . . . . . . . . . . . . 3

Statuary Bronze.--The best metals obtainable are selected and the best mixture known is always employed for statuary, on account of the enormous expenditure for labor, which forbids any economy in metal. The mixture is:

Copper . . . . . . . . . . . . . 90 Zinc . . . . . . . . . . . . . . . . 3 Tin . . . . . . . . . . . . . . . . . 6 Lead . . . . . . . . . . . . . . . I

The small quantity of lead is necessary to impart the required chasing qualities to the statue.

Mixture for trolley wheels:

Copper . . . . . . . . . . . . . 92 Zinc . . . . . . . . . . . . . . . . 2 Tin . . . . . . . . . . . . . . . . . 6

No lead is used here, as it has been shown that this mixture gives a far greater mileage than one which contains lead.

Mixture for pattern castings:

Copper . . . . . . . . . . . . . 88 Zinc . . . . . . . . . . . . . . . . 2 Tin . . . . . . . . . . . . . . . . . 8 Lead . . . . . . . . . . . . . . . 2

Good metals are necessary for pattern bronze. They come out of the sand bright and clean.

Preservat ives for But te r and Margarine. K. FISCHER AND O. GRUENERT. (Zeit. Unters. Nahr. Genussm., xxii, 553 . ) - -The re- sults of numerous experiments showed that common salt is the best preservative of butter and margarine. Specimens containing 3 per cent. of salt were quite fit for consumption after the lapse of three months, whilst other specimens which had been treated with benzoic acid, salicylic acid, boric acid, etc., had rapidly become ran- cid. With the use of salt the decomposition of the fat and casein was practically, though not quite, inhibited, but the other preservatives failed to stop this decomposition even when (in the case of butter) as much as I per cent. was added.

L igh t Emi t t ed by Fireflies. P. SINGH and S. MAULIK. (Nature, lxxxviii, I I I . ) - - A number of fireflies were placed over a photo- graphic plate and various materials interposed. The plate was affected through thin layers of wood and leather, but not appreciably through glass. Thus the rays emitted by fireflies are in some respects analogous.to RSntgen rays and ultra-violet light.