Published in NZMJ 1909;7(30):42–45 and written by Dr W J Barclay, Thames.

Upon further enquiry it was found that it is not unusual for the men attending to these engines in the cabins of launches to experience toxic symptoms of a lesser degree, e.g., headache and dizziness. Thus the engineer of this same launch stated that, on the same night as the fatality occurred, he himself “felt queer,” but was able to continue at work till the boat arrived home. He was able to help with the corpse, and rode off on a bicycle for assistance, but on returning he partially collapsed. I found him sitting in the wet grass against a fence, feeling faint and with a feeble pulse. He had to be helped indoors, but recovered with rest and stimulation.

This collapse, some time after coming into the fresh air, is like what is experienced in C.O. poisoning, and I think the engineer of this launch undoubtedly suffered from this in a minor degree.

The difference in degree of poisoning is probably explained by the fact that the visitor was sleeping in the very fore part of the cabin, in a recess extending under the deck and without any opening for ventilation, whilst the engineer was sitting at the back of the cabin receiving the benefit from an open port-hole fixed halfway forward in the cabin. Thus the visitor lay in comparatively stagnant air ; the engineer sat in the best ventilated part of the cabin.

Carbon monoxide is a particularly dangerous gas. When mixed with air it has no warning smell, and is easily breathed ; hence its action is insidious. And it is also very deadly.