“Good Lord above!” cried the Captain.

“Diphtheria,” repeated the Doctor; “and, although I dislike extremely to criticize a member of my own profession, I must say that any physician should have recognized it.”

Sophronia groaned and covered her face with her apron.

“Ain’t there—­ain’t there no chance, Doctor?” gasped the Captain.

“Certainly, there’s a chance.  If I could administer antitoxin by to-morrow noon the patient might recover.  What time does the morning train from Boston arrive here?”

“Ha’f-past ten or thereabouts.”

Dr. Morgan took his notebook from his pocket and wrote a few lines in pencil on one of the pages.  Then he tore out the leaf and handed it to the Captain.

“Send that telegram immediately to my assistant in Boston,” he said.  “It directs him to send the antitoxin by the early train.  If nothing interferes it should be here in time.”

Captain Hiram took the slip of paper and ran out at the door bareheaded.

Dr. Morgan stood in the middle of the floor absent-mindedly looking at his watch.  Sophronia was gazing at him appealingly.  At length he put his watch in his pocket and said quietly: 

“Mrs. Baker, I must ask you to give me a room.  I will take the case.”  Then he added mentally:  “And that settles my vacation.”

Dr. Morgan’s assistant was a young man whom nature had supplied with a prematurely bald head, a flourishing beard, and a way of appearing ten years older than he really was.  To these gifts, priceless to a young medical man, might be added boundless ambition and considerable common sense.

The yellow envelope which contained the few lines meaning life or death to little Hiram Joash Baker was delivered at Dr. Morgan’s Back Bay office at ten minutes past ten.  Dr. Payson—­that was the assistant’s name—­was out, but Jackson, the colored butler, took the telegram into his employer’s office, laid it on the desk among the papers, and returned to the hall to finish his nap in the armchair.  When Dr. Payson came in, at 11:30, the sleepy Jackson forgot to mention the dispatch.

The next morning as Jackson was cleaning the professional boots in the kitchen and chatting with the cook, the thought of the yellow envelope came back to his brain.  He went up the stairs with such precipitation that the cook screamed, thinking he had a fit.

“Doctah!  Doctah!” he exclaimed, opening the door of the assistant’s chamber, “did you git dat telegraft I lef’ on your desk las’ night?”

“What telegraph?” asked the assistant sleepily.  By way of answer Jackson hurried out and returned with the yellow envelope.  The assistant opened it and read as follows: 

Send 1,500 units Diphtheritic Serum to me by morning train.  Don’t fail.  Utmost importance.

J. S. Morgan.