1874.] Phenomena called Spiritual. 81 
Houdin, a Bosco, or an Anderson, backed with all the 
resources of elaborate machinery and the practice of years,— 
have all taken place in my own house, at times appointed 
by myself, and under circumstances which absolutely pre- 
cluded the employment of the very simplest instrumental 
aids. 
A third error is that the medium must select his own 
circle of friends and associates at a séance; that these 
friends must be thorough believers in the truth of whatever 
doctrine the medium enunciates; and that conditions are im- 
posed on any person present of an investigating turn of mind, 
which entirely preclude accurate observation and facilitate 
trickery and deception. In reply to this, I can state that, 
(with the exception of the very few cases to which I have 
alluded in a previous paragraph* where, whatever might 
have been the motive for exclusiveness, it certainly was 
not the veiling of deception), I have chosen my own 
circle of friends, have introduced any hard-headed un- 
believer whom I pleased, and have generally imposed my 
own terms, which have been carefully chosen to prevent 
the possibility of fraud. Having gradually ascertained 
some of the conditions which facilitate the occurrence of the 
phenomena, my modes of conducting these inquiries have 
generally been attended with equal, and, indeed, in most 
cases with more, success than on other occasions, where, 
through mistaken notions of the importance of certain 
trifling observances, the conditions imposed might render 
less easy the detection of fraud. 
I have said that darkness is not essential. It is, however, 
a well-ascertained, fa@t that when the force is weak a bright 
light exerts an interfering action on some of the phenomena. 
The power possessed by Mr. Home is sufficiently strong to 
withstand this antagonistic influence ; consequently, he 
always objects to darkness at his séances. Indeed, except 
on two occasions, when, for some particular experiments of 
my own, light was excluded, everything which I have 
witnessed with him has taken place in the light. I have 
had many opportunities of testing the action of light of 
different sources and colours, such as sun-light, diffused day- 
light, moon-light, gas, lamp, and candle-light, electric light 
from a vacuum tube, homogeneous yellow light, &c. The 
interfering rays appear to be those at the extreme end of the 
spectrum. 
I now proceed to classify some of the phenomena which 
* See note on page 79. 
VOL: Iv. (N.S.) M 
