TRANSACTIOXS OF SECTION B. 609 



cipitated is acid, tlie acid may be neutralised by adding excess of tlie carbonate, 

 but the liquid must then be well boiled to expel all the carbon dioxide, and then 

 cooled before the bromine water is added. Not only does free carbonic acid pre- 

 vent the precipitation of the cobalt, but zinc also considerably interferes with the 

 reaction. A very small amount of that metal seriously retards the precipitation 

 of the cobalt, and a large amount almost stops it altogether. 



The author has ascertained the composition of the precipitated black oxide of 

 cobalt by dissolving it in a mixture of hydrochloric acid and potassium iodide, and 

 determining the amount of iodine liberated. It is fairly constant in composition, 

 and approximates closely to the formulae Oo,,0,4 and Co.O,,. Which of these 

 more correctly represents its composition he is unable to decide, but he suggests 

 that its composition is sufficiently uniform to enable it to be used as a means for 

 the volumetric determination of cobalt, by finding the amount of iodine which it 

 liberates. The process has been tested by JMr. J. H. Davidson, B.Sc, in the assay 

 of cobalt ores, and he finds it far more rapid than the processes generally in use, 

 and at the same time quite sufficiently accurate for assay purposes. 



9. Re-port of tlie Committee on Isomorplious Sulphonic Derivatives of 

 Benzene. — See Reports, p. 8-5. 



10. Bej)ort of the Committee on Isomeric Naphthalene Derivatives. 



See Reports, p. 174. 



11. Report of the Committee on the Possibility of making Special Reports 

 more available than at ])resent. — See Reports, p. 169. 



FRIDAY, SEPTEMBER 11. 

 The following Papers and Report were read :^ 



1. Investigations at Loiv Temperatures : — (a) Densities of Solid Hydrogen, 

 Nitrogen, and Oxygen ; (b) Methods of iwoducing Solid Hydrogen and 

 Nitrogen ; (c) Latent Heats, Specific Heats, and Coefficient of Expansion 

 of Liquid Hydrogen. By Professor James Devvar, LL.D., F.R.S. 



2. The Application of Loiv Temjjeraticres to the St^idy of Biological 

 Problems. By Allan Macfadyen, M.D. 



The cellular doctrine lies at the basis of modern biological research. Living 

 matter in its simple and complex conditions consists essentially of protoplasm with 

 a contained body or nucleus. The two elements, plasmon and nucleus, constitute 

 the elementary organism— the cell. The lowest individual forms of life are 

 represented by a single cell, and such unicellular organisms may be either of a 

 vegetable or animal type. The cells in each instance exist as free living and 

 independent organisms. The higher forms of life are built up of parts in which the 



190.3. R „ 



