It was found that even when the acute poisoning had been avoided, a great lassitude was produced for some time by the inhalation of the gas. In the case of Hull's 10th Brigade, which had been practically living in the fumes for a fortnight, but had a specially bad dose on May 2, it was found that out of 2500 survivors, only 500 were really fit for duty. The sufferings of the troops were increased by the use of gas shells, which were of thin metal with highly-compressed gas inside. All these fiendish devices were speedily neutralised by means of respirators, but a full supply had not yet come to hand, nor had the most efficient type been discovered, so that many of the Allies were still poisoned.
Upon May 3 the enemy renewed his attack upon the 11th Brigade, now commanded by Brigadier-General Prowse, and the 1st Rifle Brigade, which was the right flank regiment, was badly mauled, their trenches being almost cleared of defenders. The 1st Somersets also suffered heavily. Part of the 1st York and Lancasters and the 5th King's Own Lancasters were rushed up to the rescue from the supports of the Twenty-eighth Division. The gallant Colonel of the latter battalion, Lord Richard Cavendish, was wounded while waving on his men with his cane and shouting, "Come along, King's Own." At the same time the German infantry tried to push in between the 11th Brigade on our left and the 85th on the right, at the salient between the Fourth and Twenty-eighth Divisions, the extreme north-east corner of the British lines. The fight was a very desperate one, being strongly supported by field-guns at short ranges. Three more British battalions--the 2nd Buffs, 3rd Fusiliers, and 2nd East Yorks--were thrown into the fight, and the advance was stopped. That night the general retirement took place, effected in many cases from positions within a few yards of the enemy, and carried out without the loss of a man or a gun. The retirement was upon the right of the British line, and mainly affected the Twenty-seventh, and to a less degree the Twenty-eighth, Divisions. The Fourth Division upon the left or north did not retire, but was the hinge upon which the others swung. During the whole of these and subsequent operations the Fourth Division was splendidly supported by the French artillery, which continually played upon the attacking Germans.