462 



Dr. B. Stewart on the Kew Magnetic Carves. [June 10, 



strong hydrochloric acid, and heated to about 140° for two or three hours. 

 After cooling, a layer of colourless liquid was observed floating on the top 

 of the brown tarry contents. It immediately became gaseous on opening 

 the tubes, and was presumedly chloride of methyl, as the issuing gases were 

 found to be free from carbonic acid. The residue in the tubes, when dis- 

 solved in water and precipitated by carbonate of sodium, yielded, on extrac- 

 tion with ether and agitation with hydrochloric acid, a crystalline chloride 

 having, when purified by recrystallization, all the properties of the chloride 

 of apomorphia derived from morphia. It gave the same qualitative reactions, 

 produced the same remarkable physiological effects, and yielded the follow- 

 ing numbers on combustion with chromate of lead and oxygen : — 

 0*3120 gramme gave 0*7680 carbonic acid and 0*1740 water. 



Calculated. Found. 



C 1T 



204 



67*22 



67*13 





18 



5*93 



6*19 



N 



14 



4*61 







32 



10*54 





CI 



35*5 



11*70 





C 17 H 17 N0 2 HC1 



303*5 



100*00 





Hence the reaction which takes place is in accordance with formula (4) 

 above, viz. 



Codeia. Apomorphia. 



C 17 H 17 (CH 3 ) HN0 3 + HC1=CH 3 C1+ H 2 + C 17 H 17 N0 2 . 



Doubtless there is an intermediate reaction, viz. either that indicated 

 by formula (3), where morphia is the intermediate product, or that in ac- 

 cordance with (2), where a base homologous with apomorphia, and thence 

 called apocodeia, is first produced, and subsequently split up into apo- 

 morphia and chloride of methyl, thus — 



Apocodeia. Apomorphia. 



C 18 H 19 N0 2 + HC1=CH 3 Cl+C 17 H 17 N0 2 . 

 We are at present engaged in investigating the nature of this interme- 

 diate reaction. 



V. "A Preliminary Investigation into the Laws regulating the 

 Peaks and Hollows exhibited in the Kew Magnetic Curves 

 for the first two years of their production/' By Balfour 

 Stewart, LL.D., F.R.S., Superintendent of the Kew Obser- 

 vatory. Received May 20, 1869. 



The Kew magnetographs began to be in regular operation in May 1858, 

 and have continued so up to the present date. The curves derived from 

 these instruments, representing the changes which take place in the three 

 components of the earth's magnetism at Kew, are often found to be studded 

 with small serrated appearances, which have been denominated peaks and 



