which organ is sick, which can be done on the basis of the symptoms manifested, so long as one knows 'all the organs, all the tissues that make up the means of communication by which these organs are linked together, and the changes that a modification in one organ may bring about in others';.'Explain how an organ became sick', by means of an external agent; by taking account of the essential fact that irrita lion may cause hyperactivity or, on the contrary, functional asthenia, and that 'these two modifications almost always exist together in our economy' (under the effect of cold, the activity of the cutaneous secretions diminishes, while that of the lung increases);. '