Yet another cause was contributing to restore the column as the favourite formation for the attack of cavalry. With the steady improvement in fire-arms, the bullet became more and more potent in velocity and penetration, and increasingly difficult to fend off by means of armour. It must never be forgotten that a bullet-wound, for a century and more after the introduction of fire-arms, generally meant death. The primitive surgery of the time, misled by the livid appearance of the edges of the wound, pronounced bullets to be in their nature venomous, and treated the hurt somewhat as a snake's bite, with such tortures of boiling oil and other descriptions of cautery as are sickening even to read of. Wise men took refuge in the virtues of cold water, and kept the surgeons at a safe distance. "Trust a doctor and he will kill you; mistrust him and he will insult you," wrote a Frenchman[81] who had suffered much from the profession. But above all, men relied on prevention rather than cure; so to keep bullets out of their bodies they made their armour heavier and heavier, covering themselves with stithies, to use the words of contemptuous critics,[82] till they could neither endure swift movements themselves nor find horses that could maintain any pace under the burden.[83] It was obvious therefore that if cavalry was to act by shock, the shock must be, as in former days, that of ponderous weight rather than of high speed. Moreover, quite apart from all questions of formation there was much in the prevailing tactics of infantry to encourage cavalry to change the lance for the pistol. Huge square battalions, bristling with eighteen-foot pikes and garnished with musketeers, were not easily to be broken by a charge, but presented a large mark at a fairly safe range to the mounted pistolier. Thus all circumstances conspired to favour a great and radical reform in the tactics of cavalry, the change not only from line to column, but from shock to missile action. When once the pistol was recognised as the principal weapon of the horsemen, it was obvious that all other tactical considerations must give way to the maintenance of a continuous fire. To this end there was but one system known, namely the old method of Pescayra, that the front rank should fire first and file away to the rear to reload, leaving successive ranks to come up in its place, and go through the same performance in turn. Plainly, therefore, a reversion to the old dense column, as great in depth as in breadth of front, was imperative. It was accordingly re-introduced, and from its quadrate outline was called by the name of a squadron, which from this period tends to become a term applied exclusively to cavalry. Massed together in such squadrons men could move slowly and steadily, willingly sacrificing speed that they might take the better and surer aim. [Sidenote: 1557.]