220 



THE ALUMNI JOURNAL. 



FORMALDEHYDE IN PHARMACY.* 



By F. C. J. BIRD, Ph. C, F. I. C. 



Formaldehyde is an exceedingly powerful an- 

 tiseptic, and at first sight appears to be one 

 which should prove exceptionally valuable in 

 certain pharmaceutical operations on account 

 of its intense germicidal action, the absence of 

 odor or taste in dilute solution, its non-poison- 

 ous nature, and its volatility. It has been stat- 

 ed that milk may be preserved by formalde- 

 hyde, and the antiseptic subsequently driven 

 off on boiling or cooking the milk; this state- 

 ment suggests a practicable process for the 

 preparation of liquid extracts such as ergot by 

 repercolation with cold water. The difficulty 

 of preventing the ergot liquors from turning 

 sour when working in any but the coldest 

 weather presents an almost insuperable obsta- 

 cle to the adoption of the method under present 

 conditions, but it was thought that by the use 

 of formaldehyde the ergot percolates might be 

 kept sweet, and the antiseptic finally removed 

 by the application of a moderate temperature 

 at the end of the operation. To my disappoint- 

 ment, however, I found that formaldehyde is 

 retained by aqueous liquids with the greatest 

 pertinacity, and it is almost impossible to effect 

 the removal of the last traces. The following 

 examples will illustrate this: — 



I. Forty fluid ounces water containing 80 

 minims formaldehyde solution (=1 in 600) was 

 heated to 200° F. on a water bath at intervals 

 during four days, until the volume was reduced 

 to 10 fluid ounces. Tested from time to time, 

 it always gave abundant evidence of the pres- 

 ence of formaldehyde, and on gently warming 

 the residue the characteristic odor became dis- 

 tinctly perceptible. 



II. 100 C. c. distilled water, containing i 

 minim of solution of formaldehyde (about i in 

 3800) was rapidly boiled down to 40 C. c. The 

 residue still reacted strongly for formaldehyde. 



III. 100 C. c. water containing J|j minim for- 

 maldehyde solution (=1 of formaldehyde in 

 38,000) was distilled, and the distillate collected 

 in fractions of 5 C. c, each fraction being tested 

 with Nessler's reagent. 



Fractions i to 7 gave a brownish yellow opal- 

 escence, changing to copious orange precipi- 

 tate, which gradually became yellow, and final- 

 ly blackened. 



Fractions 8 to 16. A yellow precipitate which 

 darkened on standing. 



*Read at the meeting of the British Pharmaceutical 

 Conference. 



Distillation was now stopped, and the 20 C. c. 

 remaining in the retort tested. A distinct yel- 

 low precipitate fell, indicating that the liquid 

 still contained formaldehyde. These facts will 

 evidently have to be taken into account in any 

 quantitative process dependent on the distilla- 

 tion of mixtures containing formaldehyde. 



If used as a preservative for infusions, etc., 

 the small proportion necessary does not affect 

 either the taste or flavor of the liquid, an im- 

 portant advantage when contrasted with chlo- 

 roform. The following table gives the result 

 of a trial of its antiseptic powers on four of the 

 Pharmacopoeia infusions. 



The Roman numerals represent five series of 

 samples (each measuring 10 fluid ounces) which 

 were treated as follows: 



I. No addition. 



II. Vapor from one minim formaldehyde so- 

 lution. 



III. Vapor from five minims formaldehyde 

 solution. 



IV. One minim formaldehyde solution added 

 to the infusion. 



V. Five minims formaldehyde solution add- 

 ed to the infusion. 



The infusions were kept in corked bottles, 

 exposed to most trying conditions of tempera- 

 ture, the thermometer registering from 70° to 

 80° F. during the whole week. 



Inf. Senncs, B. P. 



2d day 



3d " 



4th " 

 5th ■' 



6th " 



7th " 



Slightly 



d'comp'd 



Sour and 



putrid 



II. 



Unch'g'd 



Slightly 



d'comp'd 



Sour 



III. 



Unch'g'd 



Slight de- 

 compos'n 

 no mould 



IV. 



Unch'g'd 



Sour 



Unch'g'd 



Slightly 

 mouldy, 

 no putrid 



odor 



Mould ou 



surface 



increas'd 



Very 



mouldy 



not sour 



