198 Proceedings of the British Association for [Sept 



5. A letter was read from Dr. Turner, reporting the opi- 

 nion of the committee appointed at last meeting, to take into 

 consideration the adoption of a uniform set of chemical 

 symbols for this country. The opinion of the majority was, 

 that those used on the continent should be had recourse to. 

 It was strongly recommended that the abbreviations should 

 not be carried further than the dots for oxygen ; indeed, it 

 was suggested by some, that these should be rejected, as 

 they merely express theory, and consequently vary, accord- 

 ing to the view that is taken of the composition in this 

 country and on the continent ; but it is obvious, that if 

 brevity is not carried any further than this, no bad conse- 

 quences can follow from a system of notation. 



Dr. Thomas Thomson strongly recommended that the 

 centigrade thermometer should be adopted in this country 

 for scientific purposes, as being infinitely better adapted for 

 such purposes than that of Fahrenheit. His suggestion 

 appeared to coincide exactly with the opinion of the com- 

 mittee. 



Tuesday, Wth August. — 6. Mr. Davy detailed some experi- 

 ments which he had made upon the preservation of tin plate 

 by the agency of zinc. When exposed for some days to the 

 action of water, the plate by itself soon becomes slightly 

 corroded, but is completely preserved by the zinc, the latter, 

 at the same time oxidizing. Hence, the plate might be 

 employed in place of copper for many purposes, where 

 salt water comes in contact with vessels. Several metals 

 he had ascertained are not protected. 



7. Mr. Graham described the constitution of certain salts 

 in continuation of the papers which he has published upon 

 this subject. He views sulphuric acid as a sulphate of water, 

 and as represented by H S. Sulphuric acid of spec. grav. 

 1*78 is hydrous sulphate of water, or a hydrate expressed 

 by H S H, 1 atom being basic and essential to the composi- 

 tion of the acid, the other being driven off" by heat. Hy- 

 drated oxalic acid is an oxalate of water H (C + C) H^. 



Nitric acid = H N' H^ of spec. grav. 1-42. 



Oxalate of magnesia =Mg (C + C) H^. 



Nitrate of Copper = Cu N H ^ . 



There are three oxalates of potash, 



l.K(C + C)H. 



