17S TEAK-BOOK OF FACTS. 



always found that chemical practice was required to make such 

 knowledge available, and that for that reason it was nearly useless 

 in the hands of the public. When, too, a particular case becomes 

 mixed up with the numerous cases that may be associated with it, I 

 think it often disappears from view, and the whole are after a time 

 forgotten. Hence, I prefer adhering to the case of adulteration 

 arising from the joint action of salt water, or sea spray, and lead ; 

 and I have the full confidence that if it arise at any of your military 

 posts at home or abroad, no difficulty will be found in the effective 

 application of the remecy. 



" I am, my dear Sir John, 



" Your very faithful servant, 



"M. Faraday. 



" To Sir J. F. Burgoyne, &c, &c, &c." 



POISONOUS METALS IN CHEESE. 

 Professor Voelcker has stated to the Pritish Association that 

 he lias detected both Copper and Zinc in Cheese. In some specimens 

 copper, in others zinc, and in some both copper and zinc, were 

 found. The description of cheese in which these Poisonous Metals 

 ■were found was double-Gloucester cheese. Skimmed milk cheese, 

 which was likewise examined for copper and zinc, did not contain 

 any metallic impurity. Stilton and other varieties of cheese have 

 not as yet been examined ; it mu3t not therefore be inferred that 

 cheese made in other districts than Gloucestershire contains poisonous 

 metals. Inquiry in the dairy districts of Gloucestershire and Wilt- 

 shire has led to the discovery that in many dairies in these counties 

 sulphate of copper, and sometimes sulphate of zinc, are employed 

 in the making of cheese. The reasons for which these prejudicial 

 salts are added to the cheese are variously stated. Some persons 

 added sulphate of zinc with a view of giving new cheese the taste 

 of old ; others employed sulphate of copper for the purpose of pre- 

 venting the " heaving" of cheese. Dr. Voelcker also stated that he 

 IihI l'c uiiid alum in Gloucester cheese, ami mentioned that he had 

 learnt that in some dairies alum was employed to effect a more com- 

 plete separation of the caseitiu from the whey. 



STRYCHNINE AND CURARE. 



Our readers may recoiled that, in I S my of 



Boiences received an important communication from Dr. Valla, of 

 Turin, on th I application of the Curare or Woorali Poison 



to the oure of traumatio lock-jaw.* This was much too precious a 

 discovery not to be immediately tried in France, bnt tin- attempts 

 at Paris and al Bordeaux were only successful in two cases out 



of seven, so that this remedj Ij and l>r. \ 



success ascribed to good fortune rather than to the efficacy of the 

 poison. But after thelapseof nearly a \ ar, probably spenl In making 



cperimenta, weflnd I >r. • 

 new and highly interesting communication to I pay of 



• See the-cOBO detailed In the I r.icli, 18C0, p. 103. 



