the witnesses were among the best Chemists of the day, yet the question (simple as it might at first appear) whether oil or sugar at certain temperatures, and under certain circumstances, should be considered the more inflammable substance, occupied three days on the first and six days on the second trial. Notwithstanding which, a third trial took place involving the same question, and controversial pamphlets were published on both sides on the nature and supposed contradictions of the evidence. It has been supposed that medical practitioners may avail themselves of the privilege enjoyed by legal advisers,[232] and that they are not bound to divulge the secrets of their patients, reposed in them in the course of professional confidence;[233] undoubtedly this confidence ought not to be violated on any ordinary occasion, but when the ends of justice absolutely require the disclosure, there is no doubt that the medical witness is not only bound, but compellable to give evidence; ever bearing in mind that the examination should not be carried further than may be relevant to the point in question; of this the Court will judge, and protect the witness accordingly. In the celebrated trial of the Duchess of _Kingston_, before the House of Peers, (11 _Harg._ St. Tri. 243) this point of medical liability was raised by Mr. _Cæsar Hawkins_, and determined by Lord _Mansfield_ in the following words: “I suppose Mr. _Hawkins_ means to demur to the question upon the ground, that it came to his knowledge some way from his being employed as a surgeon for one or both parties; and I take for granted, if Mr. _Hawkins_ understands that it is your Lordships opinion that he has no privilege on that account to excuse himself from giving the answer, that then, under the authority of your Lordships judgment, he will submit to answer it: therefore to save your Lordships the trouble of an adjournment, if no Lord differs in opinion, but thinks that a Surgeon has no privilege to avoid giving evidence in a Court of Justice, but bound by the law of the land to do it; if any of your Lordships think he has such a privilege it will be a matter to be debated elsewhere, but if all your Lordships acquiesce, Mr. _Hawkins_ will understand that it is your judgment and opinion, that a Surgeon has no privilege, where it is a material question, in a civil or criminal cause, to know whether parties were married, or whether a child was born, to say that his introduction to the parties was in the course of his profession, and in that way he came to the knowledge of it. I take it for granted, that if Mr. _Hawkins_ understands that, it is a satisfaction to him, and a clear justification to all the world. If a Surgeon was voluntarily to reveal these secrets, to be sure he would be guilty of a breach of honour, and of great indiscretion; but, to give that information in a Court of Justice, which by the law of the land he is bound to do, will never be