juxta-posed

— As light, then, cannot be regarded as the photographic agent, electricity, which, in all probability, is the principle of light, would seem to be ; and the effects produced, when phosphorescence is de­veloped through juxta-posed transparent me­dia, of different densities or electrical affini­ties, bear so striking an analogy to those which are produced upon a sensitive surface when exposed to the action of light, reflected from bodies in different of intensity, as to render it more than probable, that what is understood by the term photography, is a simple case of phosphorescence by insolation.