Mr. G. Gulliver’s Observations on the Blood Corpuscles, 23 
seen by transmission, the light twice reflected causes rings 
which are easily visible, although one portion of the inter- 
fering light is less than g^o^h part of the other by the undu- 
latory formulae, and about ^i^thby my experiments; also, in 
the former experiment, the polarizing angle for glass (56^° 
nearly) is approaching towards the polarizing angle for dia- 
mond (about 68^), therefore, the whole light reflected by the dia- 
mond would be only a small fraction of the incident light, and 
that by the glass, according to Mr. Green’s formula, would bear 
a considerable ratio to it, and therefore the rings should be very 
distinct, in place of which none are to be seen at all ; so that 
Mr. Green’s formula neither represents the facts nor agrees 
with Fresnel’s. 
Professor Forbes also says, in the second sentence of his 
memorandum, “ but the chief evidence for the truth of this 
remarkable law rests on the indirect observation of the change 
of the plane of polarization of an incident ray after reflexion.” 
He here alludes to a series of valuable experiments made by 
Sir David Brewster, and published in the Phil. Trans, for 
1830. If we look over Sir David’s table at page 75, we see 
the results of the experiments on the change of the plane of 
polarization after reflexion by diamond, affbrding errors of 
observation, although, from the nature of the experiment ne- 
cessarily large, (averaging 46|-') yet all lying on one side of 
the calculated results. When the theory is true we naturally 
expect the errors of observation to fall sometimes on one side 
and sometimes on the other side of the calculated place. 
Hence, it is clear, that the undulatory theory, even in this 
vaunted case, does not give the accurate results. 
Queen’s College. 
IV, Observations on the Blood Corpuscles or Red Disks of the 
Mammiferous Animals, By George Gulliver, F,R,S,, 
Assist ant Surgeon to the Royal Regiment of Horse Guards'^', 
\ COMPLETE history of the blood corpuscles of the 
mammalia would be a very acceptable addition to ana- 
tomical science, and probably no less advantageous to zoo- 
logy. To accomplish this work, however, the co-operation of 
so many circumstances is necessary, that the contributions of 
different observers are especially desirable. I have long been 
engaged in the inquiry ; and, as I have been favoured with 
the liberal permission of the Council of the Zoological So- 
ciety t to avail myself of the advantages of their collection, I 
* Communicated by the Author, Nov. 23, 1839. 
t In returning my best thanks on this occasion to the Council, I cannot 
