424 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



and other crops, which are said to pay the proj^rietors better 

 than wine. 17 ^, XXL, 117. 



CLEANING SILVER-WARE, ETC., WITH POTATO-WATER. 



Silver and plated articles should be placed about ten min- 

 utes in the hot water in which potatoes have been boiled 

 (with salt), and then be rubbed with a woolen rag, and rinsed 

 in pure water, when the articles will not only be free from 

 tarnish, but perfectly bright. Potato-water that has become 

 sour by standing several days answers still better, and is 

 also excellent for cleaning articles of steel and glass water- 

 bottles. 5 (7, Marc\ IV., 32. 



SUBSTITUTE FOR PERSIAN INSECT-POWDER. 



The wild rosemary {Ledum 2^cilustre) has been suggested 

 as a substitute for Persian insect-powder. When dried as 

 well as fresh it is destructive to lice, bugs, fleas, moths, etc. 

 The tincture prepared from it is also a remedy for the bites 

 of gnats, and insects generally; not only relieving the itch- 

 ing in a short time, but also the pain when applied to a 

 wound. The tincture repels gnats when mixed with glyc- 

 erine and rubbed upon the skin. It seems to deserve notice 

 on account of these properties, and its possible substitution 

 for the more expensive and frequently adulterated Persian 

 insect-powder. It is most effective Avhen fresh and in bloom, 

 and should be gathered in the latter condition. 5 C, 72. 



DETECTION OF OLEOMARGARINE IN BUTTER. 



According to Mr. Horsley, it is not diflicult to determine 

 by chemical tests the presence of oleomargarine, or artificial 

 butter, as an adulteration in genuine butter. He remarks 

 that fresh butter is completely soluble in methylated ether 

 of specific gravity 0.730 at a temperature of 65. If methyl- 

 ated alcohol, 63 above proof, be added to this, and well 

 shaken, all the lard, beef, mutton, or tallow tats that may 

 have been mingled with the butter will be precipitated. 

 Care, however, is to be taken not to mistake the crystalliza- 

 tion of butter out of the ethereal solution, at a lower temper- 

 ature than 65, for the fats precipitated by the alcohol. The 

 butter, besides, being so much lighter, occupies the upper 

 layer, is different in character, and is easily remelted by the 



