4 PHILOSOPHICAL TI'.ANSACTIONS. [aNNO 1724. 



(lipped in the same brandy a large napkin 4 times folded, and applied it over 

 all the dressings, and with a couple of strong towels, which were also dipped, 

 I swathed her round the body, and then gave her an opiate medicine, which 

 was ordered to be repeated at intervals. 



Next morning I found her in a breathing sweat, .nid sbe informed me, with 

 joy, that she had not slept so much, nor found herself so well refreshed, at 

 any time for 3 months past. I carefully attended her once every day, and as 

 constantly dressed her wound in the same manner as above, for about 8 days 

 together ; I kept in the lower part of the wound a small tent, which discharged 

 some serosities at every dressing for 4 or 5 days. But business calling me else- 

 where, I left her, having first instructed her two daughters (both women, who 

 carefully attended her) how to dress her wound, and told them what diet I 

 thought most proper, enjoining them strictly to observe what I ordered. 



She afterwards mended apace to the admiration of every one, and lived in 

 perfect health from that time, which was in August 1701^ till October 1714, 

 when she died in 10 days sickness. 



That this tumor, or rather dropsy of the ovarium, proceeded from the 

 midwife's rashness in pulling away the placenta, not knowing how to separate 

 it from the uterus skilfully, seems to me plain from what the woman herself 

 told me, and what fell out afterwards. 



Method of Jjreparing Prussian Blue,* communicated from Germany, to John 

 PVoodwurd, M.D. Gresham Professor of Phijsic, and F. R. S. N°381, 

 p. 15. Translated from the Latin. 



Take of crude tartar and crude nitre dried, each f iv. Let them be reduced 

 to a fine powder and mixed together; then detonate them in a charcoal fire, and 



• This is the first account that was made public of the nietliod of preparing this blue colourj 

 the process having, until this time, been kept a secret. The discovery of this useful pigment was 

 wholly accidental. It happened (as Macquer relates from Stahl) in the following manner. A 

 manufacturer of colours, named Diesbach, who usually prepared a lake of cochineal, by mixing a 

 decoction of this substance with alum and some green vitriol, and by precipitating the mixture with 

 a fixed alkali, being one day in want of fixed alkali, borrowed from Dippel, in whose laboratory he 

 worked, some salt of tartar from which that chemist had several times distilled his animal oil, and 

 observed that the lake precipitated by means of this alkali instead of being red, was of a fine blue 

 colour. Dippel, to whom he related the appearance, knew that it must have been caused by his 

 alkali, and attempted to produce the same effects by giving the same quality to fixed alkali by an 

 easier process. In this he succeeded. This blue has been called Prussian or Berlin blue from the 

 place where it was first made. An account of it was published in the Berlin Memoirs for 1710, but 

 no description was then given of the process for making it; of which Dr. Woodward in 17'24 first 

 published the particulars in the above communication. 



