The "Potato murrain" is characterised by "the rapid putrescence of the leaves and haulm, which is first indicated by the presence of a little mould, Peronospora infestans, which preys upon the tissues, spreading rapidly in every direction. The tubers also exhibit brown spots on their surface and within their tissues, and according to circumstances decay with greater or less rapidity" (Treas. of Bot.). In 1846 the sudden inroad of this disease led to the fearful famine in Ireland, which resulted in the death of thousands. Mure made the first proving of S. t. ae., using a potato "in an entire state of decomposition, without, however, being completely rotten." Effects of eating diseased potatoes, some of them fatal, have been observed, and these have been added to Mure's. The symptoms of the proving were pretty severe, and one of the most important—prolapse of the rectum—has been confirmed by the poisoning cases. A man and three children ate boiled diseased potatoes, and among their symptoms were these: "Pain of an acute character was referred to the region of the anus, which on examination was found perfectly patulous and exquisitely tender to the touch. Two of the four patients had prolapsus ani, which was probably caused by the violent and ineffectual efforts to discharge the contents of the rectum. There had not been an evacuation of the bowels, nor had they passed water, except in drops and with extreme suffering, for six days. On introducing, the finger into the rectum, which caused acute pain, it was found that the intestine was completely filled, to within an inch of the orifice. with a solid substance." The foul odour of the diseased potato is reproduced in the breath and body odour of the patients. Lips cracked and raw; gums bleeding; tongue coated, thick, cracked; throat inflamed and ulcerated with sensation of something sticking in it or a fleshy growth. In one poisoning case a condition of noma of left cheek was induced. Peculiar Sensations are: Of water splashing on head; as if brain were leaping in skull (on stooping). As of something sticking in throat. As if there were a fleshy growth in throat. As if a spring unrolled in left hypochondrium. As if a hollow body were turning rapidly in chest. Of stoppage in trachea. Of something becoming detached from sacrum. The urine has an oily pellicle. Excruciating muscular pains. The symptoms are < by touch and pressure. Headache is < on waking; by smell of alcohol; walking at 5 p.m.; sleeping; working (headache). Cold water = shock.