TRANSACTIONS OF SECTION B. 697 



been proved beyond all doubt, not only by such experiments as that of Galippe, 

 who for fourteen months took copper with his food daily without any ill efi'ect, 

 and the classic experiments of Lehmann and his pupils on themselves for many 

 months ; but by the infinitely larger experiments made yearly by thousands of the 

 public who consume copper in some form or other in artificially coppered vegetables, 

 and in their flour, fruit, various kinds of flesh, oysters, crabs, wines, mineral 

 waters, iS:c. ' coppered ' by nature. Not one case of injury to health under such 

 circumstances has ever been brought forward, even in prosecutions for selling 

 ' coppered' peas as being ' injurious to health!' The charge is supported by the 

 allegation ' copper is a poison.' But people who eat * coppered ' vegetables do not 

 consume ' copper.' The chemical compound of copper they swallow is not copper 

 at all, and they are not injured. Even verdigris, so much feared, is not all the 

 dangerous substance alleged. Copper utensils are quite harmless with ordinary 

 cleanliness. The alleged ' poisonings ' by food cooked in copper vessels have 

 undoubtedly been mostly, if not all, due to ptomaine-poisoning. Copper has been 

 known and used longer than any other metal, and in its alloys is the most generally 

 used of all metallic substances. It has been in use from pi-ehistoric times, and its 

 dangers, if they existed, must have been known to the ancient and modern world. 

 Xet the ancients are absolutely .silent on the subject, and among moderns only a 

 few, almost entirely analysts, declaim to an incredulous public as to dangers which 

 have not been realised. The alleged fraud in so-called ' greening' of vegetables is 

 purely imaginary. The copper does not 'green' old peas or make them look 

 young. Old yellow peas when ' coppered ' still look old and yellow. The quantity 

 of the copper compound present in the amount of artificially treated vegetables 

 which is occasionally eaten at a meal is only a fraction of the corresponding 

 amount of copper sulphate which physicians prescribe to be taken three times a 

 day for weeks and months continuously. Therefore there is no sufficient ground 

 for the prohibition of the sale of ' coppered ' vegetables, any more than of the 

 innumerable kinds of fruits, vegetables, sbell-fish, cereals, mineral waters, wines, 

 and animal flesh which naturally contain the metal in some form. If the latter 

 drastic arrangement were attempted, absolute and general starvation would be the 

 inevitable result, so widely is the natural presence of copper in articles of food 

 extended. 



G. Interim Report on the Continuation of the Bihliography of 

 Sj)ectroscopy , — See Reports, p. 150. 



7. Report on Preparing a New Series of Wave-length Tables 

 of the Spectra of the Elements. — See Reports, p. 193. 



FRIDAY, SEPTE3lJ3EIt 7. 



The following Papers and Reports were read ; — 



1. The Specific Heat of Gases at Temperatures up to 400° C. 

 By H. B. Dixon, F.R.S., and F. W. Rixox, B.Sc. 



The authors have found that the specific heat of gases between 15° C. and 

 400° C. may be directly measured by heating the gas (under pressure) in a thin 

 steel cyhnder and dropping it into a water calorimeter. A repetition of the 

 experiment with the steel cylinder empty makes the method a differential one, 

 eliminating most of the experimental error. 



The specific heat of CO^ at constant volume has been thus measured between 

 15° and 115° C, 192° C, 298° C, and 398° C. The specific heat obtained at 

 115° agrees closely -with that obtained by Joly under nearly similar conditions. 



