224 A New Method of Preserving Tumours. 



During the past few years I have repeatedly felt the need of 

 some method for preserving specimens of tumours and other patho- 

 logical formations for microscopic investigation, which might prevent 

 the alterations in the cellular elements which are so apt to occur 

 with the media now in use, and also avoid the difficulty of sending 

 fluids by mail, or the delay and expense attendant upon carriage by 

 express. Since employing the plan described above, for ensuring 

 the portability of specimens of tube-casts, in spite of their exposure 

 to either very high or very low climatic temperatures, I have made a 

 few observations upon the effects of the acetate of potash solution 

 upon morbid growths, and, as a result of my researches, recommend 

 the following method : — 



Place a small fragment of any tumour or pathological structure, 

 say a quarter to half an inch square and one-tenth of an inch thick, 

 in a couple of drachms of saturated solution of acetate of potash, and 

 allow it to fully imbibe the fluid by soaking therein for forty-eight 

 hours. The solution referred to is best made by simply pouring 

 half an ounce of rain-water upon one ounce of dry granular acetate 

 of potash, in a clean bottle. When the tissue is thus fully saturated 

 with this saline liquid, remove it by means of a pair of forceps, without 

 much pressure, and insert it in a short piece of india-rubber tubing, 

 or wrap it up carefully in a number of folds of thin sheet rubber or of 

 oiled silk, tying the whole firmly at the ends with strong thread. 

 When thus prepared, specimens can be enclosed with a letter in an 

 ordinary envelope, and sent long distances, doubtless thousands of 

 miles, by mail, without danger, on the one hand, of decomposition, 

 because of the preservative power of the potassic acetate, or, on the 

 other, of desiccation, on account of its exceedingly deliquescent 

 nature. 



One very important advantage which this plan has over those 

 in which alcohol or glycerine is employed as a preservative agent, is 

 that the menstruum has little or no effect upon the oil-globules con- 

 tained in cells. Hence by its aid we are enabled to recognize fatty 

 degeneration in the cellular elements of a tumour, and easily to 

 detect the same metamorphosis in the kidneys from minute oil-drops 

 in the epithelium attached to tube-casts of Bright's disease, under 

 circumstances where specimens preserved in glycerine or alcohol 

 would afford a doubtful or wholly negative result. 



Urinary deposits composed of oxalate of lime or of triple phos- 

 phate are not, according to my experience, readily preserved in solu- 

 tion of acetate of potash, possibly on account of chemical decom- 

 positions which occur. When these crystalline bodies are met with, 

 as is usually the case, in non-albuminous urine, they could probably 

 be best retained in an unaltered state by adding from twenty to 

 thirty per cent, of solution of carbolic acid to the renal secretion in 

 which they are found. — From the Philadelphia i Medical limes' 



