JUSTUS VOX LIE BIG. 657 



day sent me a crystalline body which he had obtained by the 

 action of peroxide of lead upon this acid : I immediately there- 

 upon wrote to him with great joy, and without having analyzed 

 the body, that it was allantoin. Seven years before I had had 

 this body in my hands ; it had been sent to me by C. Gmelin for 

 investigation, and I had published an analysis of it in Poggen- 

 dorf's Annalen J since that time I had not seen it again. But 

 when we had analyzed the substance obtained from uric acid 

 there appeared a difference in the amount of carbon, the new 

 body gave one and a half per cent carbon less, and since the 

 nitrogen had been determined by the qualitative method a corre- 

 sponding quantity (four per cent) of nitrogen more ; consequently 

 it could not possibly be allantoin. However, I trusted my eye- 

 memory more than my analysis, and was quite sure that it was 

 allantoin, and the thing now to be done was to find the remains of 

 the substance previously analyzed in order to analyze it afresh. 

 I could describe the little glass in which it was with such pre- 

 cision that my assistant at last succeeded in picking it out from 

 among a couple of thousand other preparations. It looked exactly 

 like our new body, except that examination under the lens showed 

 that Gmelin, in the preparation of his allantoin, had purified it 

 with animal charcoal, some of which having passed through the 

 paper in the filtration had become mixed with the crystals. 



Without the complete conviction which I had that the two 

 bodies were identical, the allantoin produced artificially from uric 

 acid would undoubtedly have been regarded as a new body, and 

 would have been designated by a new name, and one of the most 

 interesting relations of uric acid to one of the constituents of the 

 urine of the foetus of the cow would perhaps have remained for a 

 long time unobserved. In this manner it came to pass that every- 

 thing I saw remained intentionally or unintentionally fixed in 

 my memory with equal photographic fidelity. At a neighboring 

 soap-boiler's I saw the process of boiling soap, and learned what 

 " curd soap " and " fitting " are, and how white soap is made ; and 

 I had no little pleasure when I succeeded in showing a piece of 

 soap of my own making, perfumed with oil of turpentine. In the 

 workshop of the tanner and dyer, the smith and brass-founder, I 

 was at home, and ready to do any hand's turn. 



In the market at Darmstadt I watched how a peripatetic dealer 

 in odds and ends made fulminating silver for his pea-crackers. I 

 observed the red vapors which were formed when he dissolved his 

 silver, and that he added to it nitric acid, and then a liquid which 

 smelt of brandy, and with Avhich he cleaned dirty coat-collars for 

 the people. With this bent of mind it is easy to understand that 

 my position at school was very dex)lorable ; I had no ear-memory 

 and retained nothing or very little of what is learned through this 



VOL. XL. 46 



