5 Feb 1887 Surgeon Army Medical Staff.
5 Feb 1899 Major RAMC.
Malta 7 Apr 1906 Embarked for Malta with Colonel David Bruce as a new member of the Mediterranean Fever Commission. Major Weir returned to England on 26 Sep 1906 on the Postal and Oriental Steamer Caledonia.
7 June 1907 Highly commended by the Royal Society for services rendered in connection with the investigations into the cause of Mediterranean Fever.
20 Dec 1909 Died at Lucknow from cholera, while on the journey from Darjeeling to Calcutta. Major Weir was returning here after inspecting, as Divisional Sanitary Officer, the site of a proposed new cantonment for Gurkhas, near Darjeeling, when he was seized with cholera in the train, and died on the boat while crossing from Saraghat to Railway Station, Saraghat.
He was a very exceptional man. Naturally of a most retiring, modest disposition, if he had a fault it was that he hid his own light most carefully under a bushel. To those who had the privilege of knowing him intimately, his was a most fascinating and lovable personality. A brilliant classical scholar, and a deep thinker and reader, a conversation with him on any general subject was an intellectual treat. He was of the perfect type of gentleman, the soul of truth and honour, and sensitive to a degree for others; one could never imagine him even thinking of anything mean or common. His personal charm was such, that by all his brother officers here he was looked upon with a singular devotion, and they loved to see him in the mess, and to work in his laboratory. His influence and example were priceless. He loved soldiers, too, and often spoke to me of looking forward to the time when he could give up his special line and be again in personal touch with the men. To me, who have been intimate with him since boyhood, he was more than an ordinary brother; always the loved, trusted, and faithful friend, his advice, sympathy, and companionship were priceless. I almost shudder to think of the future here without him. The Service has lost in him a very brilliant and very valuable officer. His work on the Malta Fever Commission alone must be well known, and, no doubt, appreciated at headquarters. Here he was untiring in the battle of prevention, and it seems the very acme of cruel, fateful irony that dear little Jimmy Weir should be carried off thus by one of those dire diseases, fighting which he had spent so many of the best years of his life. He will not soon be forgotten at this station. The new laboratory at the hospital, which is on the verge of completion, and in which he took such a keen interest, is to be called after him, and is to have a memorial brass sacred to his memory.