In February of the present year the Station received from a cheese manufacturer of the State two samples of rennet extract, with request for analysis and an explanation of the superior efficiency of one of them, suggesting the possibility that an extra (added) amount of free acid might be the cause. In accordance with custom, the request was complied with so far as possible. In June the same gentleman sent two more samples, and in August several more. Some of the results of investigation were so remarkable that the writer, now interested and desirous of getting at the truth, suggested duplicate samples, to avoid the danger of erroneous conclusions from single samples. Most of the samples were sent by the same gentleman; a few were obtained from other reliable sources by the writer himself. Nearly all were received in pint jars or bottles, unsealed— “broken packages” in fact. The sender of these assured me by letter that he was “very particular about every one of them, and could swear that they were exactly as recorded,” adding that they were taken from the original packages by himself and were “exactly as received.” One sample came to the writer direct from 'the manufacturer; it was the best examined of that make.