“To return to the eye, gentlemen,” says the grinder; “recollect the Petitian Canal surrounds the Cornea.  Mr. Rapp, what am I talking about?”

Mr. Rapp, who is drawing a little man out of dots and lines upon the margin of his “Quain’s Anatomy,” starts up, and observes—­“Something about the Paddington Canal running round a corner, sir.”

“Now, Mr. Rapp, you must pay me a little more attention,” expostulates the teacher.  “What does the operation for cataract resemble in a familiar point of view?”

“Pushing a boat-hook through the wall of a house to pull back the drawing-room blinds,” answers Mr. Rapp.

“You are incorrigible,” says the teacher, smiling at the simile, which altogether is an apt one.  “Did you ever see a case of bad cataract?”

“Yes, sir, ever-so-long ago—­the Cataract of the Ganges at Astley’s.  I went to the gallery, and had a mill with—­”

“There, we don’t want particulars,” interrupts the grinder; “but I would recommend you to mind your eyes, especially if you get under Guthrie.  Mr. Muff, how do you define an ulcer?”

“The establishment of a raw,” replies Mr. Muff.

“Tit! tit! tit!” continues the teacher, with an expression of pity.  “Mr. Simpson, perhaps you can tell Mr. Muff what an ulcer is?”

“An abrasion of the cuticle produced by its own absorption,” answers Mr. Simpson, all in a breath.

“Well.  I maintain it’s easier to say a raw than all that,” observes Mr. Muff.

“Pray, silence.  Mr. Manhug, have you ever been sent for to a bad incised wound?”

“Yes, sir, when I was an apprentice:  a man using a chopper cut off his hand.”

“And what did you do?”

“Cut off myself for the governor, like a two-year old.”

“But now you have no governor, what plan would you pursue in a similar case?”

“Send for the nearest doctor—­call him in.”

“Yes, yes, but suppose he wouldn’t come?”

“Call him out, sir.”

“Pshaw! you are all quite children,” exclaims the teacher.  “Mr. Simpson, of what is bone chemically composed?”

“Of earthy matter, or phosphate of lime, and animal matter, or gelatine.”

“Very good, Mr. Simpson.  I suppose you don’t know a great deal a bout bones, Mr. Rapp?”

“Not much, sir.  I haven’t been a great deal in that line.  They give a penny for three pounds in Clare Market.  That’s what I call popular osteology.”

“Gelatine enters largely into the animal fibres,” says the leader, gravely.  “Parchment, or skin, contains an important quantity, and is used by cheap pastry-cooks to make jellies.”

“Well, I’ve heard of eating your words,” says Mr. Rapp, “but never your deeds.”

“Oh! oh! oh!” groan the pupils at this gross appropriation, and the class getting very unruly is broken up.