Whilst Abulcasis bitterly declaims against the barbers, because they, in spite of their ignorance, permit themselves to perform operations on the teeth, and especially to extract them, Guy de Chauliac speaks in quite a different tone. He recognizes that such operations are _particular_, which is as much as to say, in modern language, that the practice of dental surgery constitutes a _specialty_. Guy, it is true, expresses his desire that dental operations be performed, for greater security, under the direction of doctors, but he does not use one word of blame or contempt against the _dentatores_, thus leaving it to be understood that, according to him, their art had every good reason to exist. Besides, from the enumeration of the surgical instruments which Guy says are necessary to them, we can easily argue that the _dentatores_ of the fourteenth century were not, as at the very first one might be led to believe, mere “tooth-pullers,” but that, at least, the best among them cured teeth as well as the scanty knowledge and means of cure then available enabled them to do. In the chapter on odontalgia,[243] Guy de Chauliac distinguishes between the pains, the point of departure of which is in the tooth itself, and those resulting from disease in other parts, for example, from apostema[244] of the gums; in these latter cases, in order to cause the pain to cease, it is necessary to cure the part from which the pain is derived, taking into account the nature of the disease and its causes. When the pain is situated in the root of the tooth or in its nerve, it is necessary, says the author, to distinguish whether it is caused by an accumulation of morbid matter, or whether it is, instead, a simple pain _without matter_. Besides, it is necessary to distinguish, in the first case, whether the matter producing the pain is hot, cold, or windy; and also, in the second case, it is necessary to ascertain if the pain is of a warm, cold, dry, or humid nature. As may be seen, the principles and subtle distinctions of the pneumatic school were then in full vigor. The treatment must vary according to all the aforesaid cases; but the means of cure advised by Guy de Chauliac do not present any special interest, as they are almost entirely taken from Galen and from the Arabian authors, and especially from Rhazes, Ali Abbas, and Avicenna. On coming to speak of the looseness of teeth,[245] Guy says that this may depend on various causes: that is, on a fall or a blow; on humidity, which softens the nerve and ligament;[246] on dryness and lack of nourishment of the teeth; and lastly, on corrosion of the gums.