450 lloyal Society. 



and gives the details of a series of observations on the blood of a 

 human foetus that was born alive at the end of the sixth month. 

 He examined the blood of the parent, and of the placenta, and also 

 of different parts of the body of the foetus a few hours after death, 

 and found in general that the blood of the parent contained a very 

 large quantity of white chyle corpuscles, and was extremely coagu- 

 lable : the blood of the placenta contained, beside an abundance of 

 chyle corpuscles, red blood-discs of extremely variable sizes, the 

 largest being one-third or one-fourth larger than those of the 

 mother, and the smallest scarcely more than one-fourth as large as 

 the largest. There were also an immense abundance of molecules 

 and nucleoli, from which latter the red blood-discs appeared to be 

 developed. The blood of the vein and lungs presented a similar ir- 

 regular condition as to size of the corpuscles, while that of the left 

 auricle of the heart, aorta and arteries of the cord was more uniform 

 in its character. From these observations the author concludes, 

 that the blood of the vertebrata is analogous in its mode of develop- 

 ment to that of the insects and other invertebrata, and that the red 

 blood-discs are the ultimate developments of the opake white gra- 

 nules or nucleoli of the blood. 



Drawings illustrating the subjects accompany the paper. 



February 20. — " Additional Remarks respecting the Condensation 

 of Gases." By Michael Faraday, Esq., F.R.S. &c. 



The author, suspecting the presence of nitrogen in the nitrous 

 oxide on which he had operated, repeated his experiments with this 

 gas, very carefully prepared from pure nitrate of ammonia, but the 

 results still indicated the presence of a more volatile gas mixed with 

 another less volatile. He found that olefiant gas is readily soluble 

 in strong alcohol, aether, oil of turpentine, and other bodies of the 

 same kind ; and that, like the former gas, it seems to be of a com- 

 pound nature. His experiments confirm the prevalence of the law 

 that the force of vapour increases in a geometrical ratio for equal 

 increments of heat, commencing at a given amount of pressure. The 

 more volatile a body is, the more rapidly does the force of its vapour 

 increase by an augmentation of temperature, the increase of elasti- 

 city being directly as the volatility of the substance. By further and 

 more accurate investigation, a general law may be established for 

 deducing, from only a single observation of the force of any given 

 vapour in contact with its fluid, its elasticity at any other tempera- 

 ture. 



Postscript to the Paper by Sir John F. W. Herschel, Bart., F.R.S., 

 read at the last meeting. 



The author found that neither cinchonine nor salicine, in a state 

 of great purity, possessed, in the smallest appreciable degree, the 

 optical property which he has shown to belong to quinine. 



February 27. — " An Account of Compact Aluminum," by Pro- 

 fessor F. Wohler of Gottingen, in a Letter to Thomas Graham, Esq. 

 Communicated by Thomas Graham, Esq., F.R.S. 



The author has lately found, contrary to the results of his former 

 researches on aluminum made eighteen years ago, that this metal is 



