Latter or former

Please help, I have kept reading this old article dated 1921. I am comfused. May I know who is the latter and the former.  

The Latter is Dr. Conwell

The Former is Dr. Alexander 

Dr. Alexander seems to have been a keen and resourceful officer, but was not at all a favourite with his official superiors. 

The idea of a leper asylum at Jerejak Island originated with him, as also the first suggestion of quarantine boarding of ships 

to stop the entry of smallpox, which was so frequent in the early days. The Government generally ignored his suggestions, 

which made him somewhat querulous. But the climax came when he had to go to China on sick leave, leaving Assistant 

Surgeon W. E. E. Conwell, M.D., in charge. Dr. Conwell was an energetic man, with the ear of the Government, but had the 

fatal habit of rearranging a house during an ephemeral occupation. The subsequent protests of Dr. Alexander led to the

 latter's retirement, but fortunately not to the former's preferment.

Thank You very much