A Mahomm?dan male, aged 19, attended the Jainagar dispensary as an out-patient, during my incumbency, with swelling of his left leg. On questioning, he narrated that about six months previously, he had had an attack of fever associated with intense pain in the left leg with a reddish, painful, linear mark extending throughout the limb. This lasted about a fortnight, but disappeared on application of some embrocation from a local sympathiser. Then, after a month or so, he began to notice a painless swelling of his limb which continued to increase for six months; the limb grew to double the girth of the other sound leff. . i .< On examination I found that the swelling was solio> painless, and not pitting on pressure to any notable degree. _ , From the above history and the present condition ot the patient I made a provisional diagnosis of filariasiSAs arsenic has been said to be of much value in the treatment of such filarial cases, I chose arrhenol, 311 organic preparation of arsenic. The following morning I injected him intravenously with a solution of arrhenol (gr. ii to 1 c.c. of distilled water) and gave the following mixture.