144 THE AMERICAN MONTHLY [May, 



ary mimuii ». I can say that I have had consiclcrahlc experience 

 in tliis line of work, but know of no permanent way of preserv- 

 injj the corpuscles aftei inordantin*; from :i stain lu'vond a week 

 or ten davs' time. 



F*or mordanting or separating; the corpuscles, a solution of 33",', 

 of caustic potash is superior to all else. If carefully sealed, tiiey 

 may be preserved a short time in this solution ; not, however, 

 without the formation of some crystals fiom the potash. Proba- 

 blv a better solution for preserving and mounting the corpuscles 

 wcjuld be a solution of the glycerin of the same specific gravity of 

 the blood serum. W. N. Shek.man. 



Mf.hcki>. Cai... Miirch 20, 'gj. 



{XT,) Blood Stains. — Replying to Problem No. 4, on page 50 of 

 the Jt>L"HNAi, for February. 1^9;^, I would say: 



Blood-corpuscles mav be restored to perfect form and shape 

 (not all of them) from dried blood, and are so proven by measure- 

 ment, which I have demonstrated to my satisfaction many times. 

 It cannot alwavs be done bv tiie methods (solutions) mentioned 

 in the reply to Qiiestion 139, II. M. P., on page 45, vol. i, No. 

 3, of the Slicroscope for March, 1S93, but with the caustic potash 

 solution I have often succeeded in demonstrating and measuring 

 them in 30 minutes. I can demonstrate this assertion positively. 

 The New York Medico-Legal Society recently asserted that any 

 skilful microscopist could distinguish human blood from that of 

 the domestic animals, and a great many scientific men coincide 

 with it in this view. 



The opponents to the identification of blood have twice made 

 an eflbrt to use the American Microscopical Society to sustain 

 their side of the question, but have as often failed. The proof 

 of their perfect restoration can be demonstrated and illustrated by 

 photomicrographs. \\ . N. SiinHMAX. 



Merceo, Cai... April ig, iSgj. 



(14) Cheaper Instruments. — \Ve think that our Star Micro- 

 scope ought to meet the wants of your subscribers who require a 

 cheap instrument. For a little over $20, they get a good out- 

 fit. This is a special! v low price, but if it is too high we can get to 

 work and possiblv make a cheaper instrument. This one 

 has a joint and it might be possible to make one very much 

 cheaper than this. We want your ideas on the subject. 



Williams, Brown & Eaklk. 

 PHlL.\nF.i.PHlA. Fehruary. H /8gj. 



(15) A Microscopical Index. — To get the greatest value out of 

 mv file of microscopical journals, I bought a letter file for fifty 

 cents, made of stout paper. It has an index. After reading a 

 periodical carefully I write upon paper 2^ x 3 inches a reference 

 to the title of each item, adding, of course, the volume and number 

 of the journal. I file these slips alphabetically in the compart- 

 ments of the indexed file. This in time will make a complete 



