by this thought-created picture. One striking illustration is that of a force raying outwards, the projection of an earnest prayer. Another prayer is seen producing forms like the fronds of a fern, another like rain pouring upwards, if the phrase may be permitted. A rippled oblong mass is projected by three persons thinking of their unity in affection. A young boy sorrowing over and caressing a dead bird is surrounded by a flood of curved interwoven threads of emotional disturbance. A strong vortex is formed by a feeling of deep sadness. Looking at this most interesting and suggestive series, it is clear that in these pictures that which is obtained is not the thought-image, but the effect caused in etheric matter by its vibrations, and it is necessary to clairvoyantly see the thought in order to understand the results produced. In fact, the illustrations are instructive for what they do not show directly, as well as for the images that appear. It may be useful to put before students, a little more plainly than has hitherto been done, some of the facts in nature which will render more intelligible the results at which Dr Baraduc is arriving. Necessarily imperfect these must be, a physical photographic camera and sensitive plates not being ideal instruments for astral research; but, as will be seen from the above, they are most interesting and valuable as forming a link between clairvoyant and physical scientific investigations. At the present time observers outside the Theosophical Society are concerning themselves with the fact that emotional changes show their nature by changes of colour in the cloud-like ovoid, or aura, that encompasses all living beings. Articles on the subject are appearing in papers unconnected with the Theosophical Society, and a medical specialist[1] has collected a large number of cases in which the colour of the aura of persons of various types and temperaments is recorded by him. His results resemble closely those arrived at by clairvoyant theosophists and others, and the general unanimity on the subject is sufficient to establish the fact, if the evidence be judged by the usual canons applied to human testimony. The book _Man Visible and Invisible_ dealt with the general subject of the aura. The present little volume, written by the author of _Man Visible and Invisible_, and a theosophical colleague, is intended to carry the subject further; and it is believed that this study is useful, as impressing vividly on the mind of the student the power and living nature of thought and desire, and the influence exerted by them on all whom they reach. [Footnote 1: Dr Hooker, Gloucester Place, London, W.] THE DIFFICULTY OF REPRESENTATION We have often heard it said that thoughts are things, and there are many among us who are persuaded of the truth of this statement. Yet very few of us have any clear idea as to what kind of thing a thought is, and the object of this little book is to help us to conceive this.