66 Notes and Memoranda. 



ties. The plumbago, thus obtained in a pure form, is washed and 

 heated, the result of the combined mechanical and chemical action 

 of these operations is, that the plumbago is so perfectly disintegrated 

 as to be formed into light floculi, which are capable of being blown 

 away by the slightest current of air. In this condition they are 

 readily condensed into solid blocks by pressure. 



Phosphorized Copper and Brass. — The peculiar effects of the 

 presence of small portions of phosphorus on the properties of metallic 

 copper have been studied carefully by Mr. Parkes, who has taken 

 out a patent for the application of phosphorus to the improvement 

 of the working properties of metallic copper. Phosphorized copper, 

 as it is termed, possesses an extreme degree of malleability and may 

 be forged readily even when heated to redness ; it is so ductile that 

 it is capable of being drawn out into tubes which can be flattened 

 in various directions, or even tied into close knots without showing 

 any evidence of cracking ; these tubes are made, in the first instance, 

 by casting them of a large size, and the diameter is then reduced by 

 drawing them in the same manner as wire. The extreme ductility 

 of phosphorized copper is shown by the production of a long tube 

 with a bore as fine as a needle, which has been reduced down by 

 drawing from a nine inch casting. Brass manufactured from phos- 

 phorized copper also retains many of its valuable properties. 



Insect-destroying Powder. — The exact nature of the preparation 

 so well known as the Persian insecticide powder, has not been gene- 

 rally known. It is produced by the Pyretlirum roseum caucasicum, 

 a composite flower growing wild in the Caucasus. The central or 

 tubular florets of the disc are alone employed, and when ground 

 furnish the powder known in commerce. The plant belongs to the 

 same genus as the common feverfew of our hedgerows; several 

 species of Pyrethrum the natives of England and other temperate 

 climates ; and ■ it would be interesting to ascertain whether those 

 florets possess the same destructive influence on insect life. Speci- 

 mens of the plant and its flowers in the various stages of manufac- 

 ture, are shown in the Austrian and in the Russian courts. 



NOTES AND MEMORANDA. 



Tobacco Smoking- and Angina Pectoris. — In a communication to the- 

 ]?rench Academy on the 9th of June, M. Beau connects the practice of tobacco- 

 smoking with that very painful and dangerous disorder, angina pectoris. In one 

 case a gentleman of sixty passed the greater part of one day in smoking, and 

 during a month he suffered violent palpitations at night, accompanied by oppression 

 and shooting pains in the shoulders. On leaving off smoking, the symptoms dis- 

 appeared. Three months afterwards he betook himself again to tobacco, and 

 brought back the complaint, which finally left him when the narcotic weed was 

 definitively abandoned. In the second case a physician about fifty smoked 

 cigarettes all his spare time, his digestion was bad, and he suffered nightly attacks- 

 of angina. He gave up smoking, and the disease subsided, but sitting in a room 

 filled with tobacco smoke was enough to cause a return of the pains on the fol- 

 lowing night. In the third instance a physician of thirty-five smoked as he went 

 his rounds in the country, and for a long time suffered loss of appetite. One 



