The patient is restless, often semi-delirious, and his skin may be dry and hot, or cold in the final collapse, though it is not often damp with perspiration. The hurrying small pulse and the panting rapid shallow breathing, often with sounds of fluid in the trachea, are both characteristic. Examination of the chest finds physical signs very similar to those of the blue congested type, a little dulness on percussion and numerous fine râles and rhonchi, especially in the axillae and over the back. In both cases the intensity of the pulmonary oedema is hidden from physical examination by the presence everywhere in the lungs of scattered islets of emphysema. [Illustration: PLATE III.] PLATE NO. IV Gangrene of foot caused by vascular thrombosis from chlorine poisoning. _History of case._ Gassed by chlorine in 1915 under conditions which could not have induced frost-bite. Severe dyspnoea from pulmonary oedema. Drawing of foot made on fifth day. Both feet were then anaesthetic, stone cold, and no pulsation could be felt in the dorsalis pedis artery. The right hand also was mottled, cold, and painful. The circulation was restored in a few days with complete recovery, except that two toes became black and shrivelled. Such arterial thrombosis, of slowly progressive onset, is quite uncommon in the extremities, though it is occasionally seen with phosgene. The obstruction is very rarely so complete as to cause gangrene and death of the tissues. But this drawing of a visible condition is introduced in order to emphasize the fact that an unseen vascular thrombosis of smaller vessels in deeper organs of the body is frequently found with phosgene poisoning. Such thrombosis is revealed by the microscope in fatal cases in the smaller lung vessels, in the kidney, in the mucous membrane of the stomach, and in the brain. Indeed in deaths with prolonged asphyxia from gassing by phosgene the white matter of the brain is often seen to be thickly sown with brownish-red petechial spots around each tiny arterial thrombus. The obstruction to the lung circulation has already been referred to; the kidney thrombosis does not appear to have any serious results; and, except where larger haemorrhages have burst in the brain, the scattered cerebral thrombi do not appear to be of grave clinical import. The petechial areas within the stomach may occasionally become the seat of a superficial ulceration. Large thrombi are sometimes found within the heart, but they also are associated with rather than the cause of the other changes that lead to death. [Illustration: PLATE IV.] PLATE NO. V Erythema of skin from general exposure to the vapour of yellow cross substance. Dermatitis of this distribution and associated with conjunctivitis forms a characteristic picture of poisoning by this vesicant.